tag:blogger.com,1999:blog-91625655420822030582024-03-26T01:32:53.838-07:00Palaeocritti BlogHans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.comBlogger191125tag:blogger.com,1999:blog-9162565542082203058.post-11484882352716199272023-05-18T12:12:00.002-07:002023-05-18T12:12:17.293-07:00Bad News<br />
The google site palaeocritti actually is down now.
<br /><br />
I click this link:
<br /><br />
<a href="https://sites.google.com/site/palaeocritti/by-group/gorgonopsia/aelurosaurus">https://sites.google.com/site/palaeocritti/by-group/gorgonopsia/aelurosaurus</a>
<br /><br />
This happens:
<br /><br />
<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8N_BreelKRY0jQpDcmwKaZL5T1ljTRHvMwL39PgA0gm90_z1ZQaLsiqhb3DZY6DEuA5yqBJW_TGKV8f-Ly_v_DBByFDDLT_1w8vupMV4q-5wsuRoK-7j56YodpiJDy4uhrgxeYnjouxL58T6plt_T-AmG7ocwb8eiPNbNSpgVVTqF_e3KdbN3k_vb/s863/impossible.jpg" style="display: block; padding: 1em 0; text-align: center; "><img alt="" border="0" width="320" data-original-height="222" data-original-width="863" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8N_BreelKRY0jQpDcmwKaZL5T1ljTRHvMwL39PgA0gm90_z1ZQaLsiqhb3DZY6DEuA5yqBJW_TGKV8f-Ly_v_DBByFDDLT_1w8vupMV4q-5wsuRoK-7j56YodpiJDy4uhrgxeYnjouxL58T6plt_T-AmG7ocwb8eiPNbNSpgVVTqF_e3KdbN3k_vb/s320/impossible.jpg"/></a></div>
<br /><br />
Back in November 2016, and a long time after that, the non-payment of the site simply meant one had to use:
<br /><br />
<a href="https://sites.google.com/site/palaeocritti/by-group/gorgonopsia/aelurosaurus">https://sites.google.com/site/palaeocritti/by-group/gorgonopsia/aelurosaurus</a>
<br /><br />
instead of:
<br /><br />
<a href="www.palaeocritti.com//by-group/gorgonopsia/aelurosaurus">www.palaeocritti.com//by-group/gorgonopsia/aelurosaurus</a>
<br /><br />
as previously.
<br /><br />
Now, the material itself is gone.
<br /><br />
Which is bad for Young Earth Creationists, since it gave access to lots of details which could help to debunk the claims presented as generalities derived from such details.
<br /><br />
I wanted to check out T Rex on it, because I remembered it said "30 skeletons" ... Palaeofieldguide is still up, it gives less detail, for T. Rex it says:
<br /><br />
<blockquote>Several skeletons</blockquote>
<br /><br />
<a href="https://sites.google.com/site/paleofieldguide/tyrannosaurus">https://sites.google.com/site/paleofieldguide/tyrannosaurus</a>
<br /><br />
I did not want to get fooled into not saving it./HGLHans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-36724282924597845052016-11-04T07:17:00.001-07:002016-11-04T07:17:45.885-07:00Good News!<br />
Saint Charles Borromeo is praying for me.
<br /><br />
On the url "palaeocritti.com" you find nothing, domain is up for sale, and the guys who did it haven't paid for it.
<br /><br />
HOWEVER, this does not delete their materials.
<br /><br />
Same site is actually available under a longer url. As I found out while looking at Aelurosaurus felinus.
<br /><br />
<a href="https://sites.google.com/site/palaeocritti/by-group/gorgonopsia/aelurosaurus">https://sites.google.com/site/palaeocritti/by-group/gorgonopsia/aelurosaurus</a>
<br /><br />
And classification by location is also there:
<br /><br />
<a href="https://sites.google.com/site/palaeocritti/by-location">https://sites.google.com/site/palaeocritti/by-location</a>
<br /><br />
Parallel work is also done by this site:
<br /><br />
<a href="https://sites.google.com/site/paleofieldguide/by-country">https://sites.google.com/site/paleofieldguide/by-country</a>
<br /><br />
My back up blog was not necessary, but it was a good exercise for me!
<br /><br />
Hans Georg Lundahl
<br />Nanterre UL
<br />Saint Charles Borromeo
<br />4.XI.2016Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-63447110337822075732016-08-10T11:34:00.001-07:002016-08-10T11:34:49.845-07:00Mission failed<br />
I now see that the original palaeocritti site has gone down.
<br /><br />
Only FEW of the material have been saved onto this blog.
<br /><br />
I wanted to check if land dinosaurs had been found in Holy Land, Elasmosauri had, but these are sea reptiles.
<br /><br />
Palaeocritti was the site to consult, I had not yet done Holy Land in this salvage blog. Now it is too late./HGLHans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-40629018024624933992016-01-14T02:38:00.002-08:002016-02-27T06:32:48.412-08:00Carcharodontosaurus saharicus + iguidensis<b>Carcharodontosaurus was a large meat-eating theropod from the Early Cretaceous of Africa. Its huge skull with powerful jaw equipped with long serrated teeth make it a formidable predator. Carcharodontosaurus was originally described by French paleontologists Deperet and Savornin in 1925 as a species of Megalosaurus from fragmentary remains found in the desert of Algeria. The name Carcharodontosaurus was coined by Stromer in 1931. The original material was destroyed during WWII but additional fossils were found later. In 2007, Brusatte and Sereno described a new species from Niger, C. iguidensis.</b>
<br /><br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/carnosauria/carcharodontosaurus"><i>Carcharodontosaurus saharicus</i></a> [+ C. iguidensis]
<br /><br />
<dt>Authority
<dd>(Deperet & Savornin, 1925) Stromer, 1931
<br /><br />
<dt>Meaning of generic name
<dd>Carcharodon (Jagged teeth =) Shark [+ sauros] Lizard
<br /><br />
<dt>Meaning of specific names
<dd>[from Sahara desert, + from Iguidi of Agadez district in Niger]
<br /><br />
<dt>Size
<dd>Length: 13.5 m
<br /><br />
<dt>Remains
<dd>Fragmentary skull and associated postcrania.
<br /><br />
<dt>Age and Distribution
<dd>Baharija Formation (Cenomanian), Marsa Matruh Egypt; Tegana Formation Ksar-es-Souk Morocco; Chenini Formation "Continental intercalaire" Medinine, Tunisia; "Continental intercalaire" (Gharyan) Lybia; "Continental intercalaire" Adrar Tamenghest Wargla (Albian), Algeria; "Continental intercalaire" Agadez, Niger
<br /><br />
<dt>Classification
<dd>Dinosauria Saurischia Theropoda Carnosauria Carcharodontosauridae
<br /><br />
<dt>Further Reading
<dd>C. Depéret and J. Savornin. 1925. Sur la découverte d'une faune de Vertébrés albiens à Timimoun (Sahara occidental) [On the discovery of a fauna of Albian vertebrates at Timimoun (western Sahara)]. Comptes Rendus des Hebdomadaires des Seances de l'Academie des Sciences à Paris 181:1108-1111.
<br /><br />
S. Brusatte and P. C. Sereno. 2007. A new species of Carcharodontosaurus (Dinosauria: Theropoda) from the Cenomanian of Niger and a revision of the genus. Journal of Vertebrate Paleontology 27(4):902-916
<br /><br />
<dt>Synonyms
<dd><i>Megalosaurus saharicus</i> Deperet & Savornin, 1925; <i>Dryptosaurus saharicus</i> (Deperet & Savornin, 1925)</dl> Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-50613183580795961162016-01-14T02:37:00.001-08:002016-01-14T02:37:13.329-08:00Rugops primus<br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/ceratosauria/rugops"><i>Rugops primus</i></a>
<br /><br />
<dt>Authority
<dd>Sereno, Wilson and Conrad, 2004
<br /><br />
<dt>Meaning of generic name
<dd>Ruga, wrinkle (Latin); ops<i>, face (Greek).
<br /><br />
<dt>Meaning of specific name
<dd>primus, first (Latin). Named for its significance as one of the earliest abelisaurids with textured external skull surfaces.
<br /><br />
<dt>Size
<dd>Length: 24 - 30 ft (7 - 9 m)
<br /><br />
<dt>Remains
<dd>Holotype: MNN IGU1, Partial cranium lacking the posterolateral portions of the skull roof and palate.
<br /><br />
[Skull length nearly measured, part lacking calculated, body length calculated, then.]
<br /><br />
<dt>Age and Distribution
<dd>Horizon: Echkar Formation, Upper Cretaceous (Cenomanian).
<br /><br />
Locality: Near In Abangharit, Niger Republic, Africa
<br /><br />
<dt>Classification
<dd>Dinosauria Saurischia Theropoda Ceratosauria Abelisauroidea Abelisauridae
<br /><br />
<dt>Further Reading
<dd>Sereno, P., Wilson, J. & Conrad. 2004. New dinosaurs link southern landmasses in the Mid-Cretaceous. Proceedings of the Royal Society of London. Series B, Biological Sciences, 271, 1325-1330.</dl>
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-72641817033901011562016-01-14T02:30:00.001-08:002016-01-14T02:30:44.208-08:00Kaprosuchus saharicus<b>Kaprosuchus is known from only a single almost complete skull discovered in Niger. This crocodyliform was nicknamed "boar croc" after its unusual caniniform teeth which resemble those of a boar. It has been <i>estimated</i> that Kaprosuchus may have reached lengths of 6 metres. It is thought that this crocodyliform would have been strictly a terrestrial (living on land) animal and certainly a feared predator!</b>
<br /><br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/crocodylomorpha/kaprosuchus"><i>Kaprosuchus saharicus</i></a>
<br /><br />
<dt>Authority
<dd>Sereno & Larsson , 2009
<br /><br />
<dt>Meaning of generic name
<dd>Kapros, boar (Greek); souchos, crocodile (Greek).
<br /><br />
<dt>Meaning of specific name
<dd>Sahara, Sahara Desert; -icus, belonging to (Greek).
<br /><br />
<dt>Size
<dd>Body length: 6 m , Skull length: 50 cm
<br /><br />
<dt>Remains
<dd>Holotype (MNN IGU12): nearly complete skull.
<br /><br />
[Body length calculated, skull length actually measured, most of it at least: photo does not look like back of skull is there, but that might be because I know too little of croc skulls in general.]
<br /><br />
<dt>Age and Distribution
<dd>Horizon: Echkar Formation, Tegama Series; Upper Cretaceous (Cenomanian).
<br /><br />
Locality: Iguidi, Agadez District, Niger.
<br /><br />
<dt>Classification
<dd>Crocodylomorpha Neosuchia Mahajangasuchidae.
<br /><br />
<dt>Further Reading
<dd>P. C. Sereno and H. C. E. Larsson. 2009. Cretaceous crocodyliformes from the Sahara. ZooKeys 28:1-143.</dl>Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-12047717311149561022016-01-14T02:28:00.002-08:002016-01-14T02:28:39.853-08:00Suchomimus tenerensis<b>This large theropod from Niger was very similar to Baryonyx to the point that some author placed it in the same genus. It had an elongated crocodile-like snout equipped with sharp teeth ideal for catching fish. It lived in the similar marshy environments than the modern crocodiles. Blade shape vertebral spines form a low sail over the hips.</b>
<br /><br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/spinosauroidea/suchomimus"><i>Suchomimus tenerensis</i></a>
<br /><br />
<dt>Authority
<dd>Sereno, Beck, Dutheil, Gado, Larsson, Lyon, Marcot, Rauhut, Sadleir, Sidor, Varricchio, Wilson & Wilson, 1998
<br /><br />
<dt>Meaning of generic name
<dd>Crocodile mimic
<br /><br />
<dt>Meaning of specific name
<dd>[From Tenere Desert]
<br /><br />
<dt>Size
<dd>Length: 11 m
<br /><br />
<dt>Remains
<dd>Nearly complete skeleton with skull.
<br /><br />
<dt>Age and Distribution
<dd>Elrhaz Formation (Late Aptian), Tenere Desert region, Niger.
<br /><br />
<dt>Classification
<dd>Dinosauria Saurischia Theropoda Spinosauroidea Spinosauridae
<br /><br />
<dt>Further Reading
<dd>P. C. Sereno, A. L. Beck, D. B. Dutheil, B. Gado, H. C. E. Larsson, G. H. Lyon, J. D. Marcot, O. W. M. Rauhut, R. W. Sadleir, C. A. Sidor, D. D. Varricchio, G. P. Wilson, and J. A. Wilson. 1998. A long-snouted predatory dinosaur from Africa and the evolution of spinosaurids. <i>Science</i> 282:1298-1302.
<br /><br />
<dt>Synonyms
<dd><i>Cristatusaurus lapparenti</i> Taquet & Russell, 1998</dl>Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-44755812972184798072016-01-14T02:27:00.000-08:002016-01-14T02:34:39.936-08:00Spinostropheus gautieri<br />
<dl><dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/ceratosauria/spinostropheus"><i>Spinostropheus gautieri</i></a>
<br /><br />
<dt>Authority
<dd>Sereno, Conrad and Wilson, 2004 originally described as Elaphrosaurus gautieri, Lapparet, 1960
<br /><br />
<dt>Meaning of generic name
<dd>Spine Vertebra in Greek. Named for the prominent epipophyseal processes on the cervical vertebrae and its moderate body size
<br /><br />
[was earlier, with my earlier comment:]
<br /><br />
<dt>Meaning of generic names
<dd>Spine Vertebra <i>+ turning </i>in Greek. Named for the prominent epipophyseal [?] processes on the cervical vertebrae and – elaphrosaurus synonym – its moderate body size and its being a lizard
<br /><br />
[“prominent epipophyseal [?] processes” = disease?]
<br /><br />
<dt>Meaning of specific name
<dd>After Geologist F. Gautier
<br /><br />
<dt>Size
<dd>Body length: 12 ft (4 m)
<br /><br />
<dt>Remains
<dd>Holotype: Isolated mid-cervical vertebrae
<br /><br />
Referred Specimen: MNN TIG6, articulated axial column preserving the third cervical to the anterior sacrals with complete cervical and more fragmentary dorsal ribs. Cervical and dorsal vertebrae overlap with the holotypic specimen.
<br /><br />
[Neither head nor extremities!]
<br /><br />
<dt>Age and Distribution
<dd>Horizon: Tiouraren Formation, Irhazer Group, Lower Cretaceous Period (Lower Berriasian - Upper Barremian)
<br /><br />
Locality: Niger, Africa
<br /><br />
<dt>Classification
<dd>Dinosauria Saurischia Theropoda Ceratosauria
<br /><br />
<dt>Further Reading
<dd>Lapparent (1960). "Les dinosauriens du 'Continental intercalaire' du Sahara central." <i>Mem. Soc. Geol. France.</i> 88A:1-57.
<br /><br />
Sereno, P.C., Wilson, J.A., & Conrad, J.L. 2004. New dinosaurs link southern landmasses in the Mid-Cretaceous. <i>Proceedings of the Royal Society of London: Biological Sciences</i> 271: 1325-1330.
<br /><br />
[Earlier also]
<br /><br />
<dt>Synonyms
<dd>Elaphrosaurus gautieri</dl>Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-55884659541870867912016-01-14T02:25:00.001-08:002016-01-14T02:25:09.840-08:00Spinophorosaurus nigerensis<b>Spinophorosaurus is a basal sauropod from the Middle Jurassic of Niger. Known from two almost complete skeletons, it is to date the most complete basal sauropod discovered. It has a number of features that make it a close relative of the Asian basal sauropods such as Shunosaurus, rahter than to the Gondwanan genera. Spiky osteoderms found in association with the skeletons were probably placed at the end of the tail in the living animal to serve as a defense against predators.</b>
<br /><br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/spinophorosaurus"><i>Spinophorosaurus nigerensis</i></a>
<br /><br />
<dt>Authority
<dd>Remes, Ortega, Fierro, Joger, Kosma and Ferrer, 2009
<br /><br />
<dt>Meaning of generic name
<dd>The genus name refers to the presence of spikebearing osteoderms, Latin spina, spike, Greek phoro, to bear, and sauros, lizard
<br /><br />
<dt>Meaning of specific name
<dd>[from Niger]
<br /><br />
<dt>Size
<dd>Length: 13 m
<br /><br />
<dt>Remains
<dd>Holotype (GCP-CV-4229 and NMB-1699-R): partial skull and nearly complete postcranial skeleton.
<br /><br />
Paratype: NMB-1698-R, a partial skull and incomplete postcranial skeleton.
<br /><br />
<dt>Age and Distribution
<dd>Horizon: base of the Irhazer Group, possibly Middle Jurassic (Bajocian-Bathonian) or even Lower Jurassic.
<br /><br />
Locality: Thirozerine Dept., Agadez Region, Republic of Niger.
<br /><br />
<dt>Classification
<dd>Dinosauria Saurischia Sauropoda
<br /><br />
<dt>Further Reading
<dd>Remes, K., Ortega, F., Fierro, I., Joger, U., Kosma, R. and Ferrer, J.M.M. 2009. A new basal sauropod dinosaur from the Middle Jurassic of Niger and the early evolution of sauropoda. PLoS ONE, 4(9): e6924.</dl>Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-3121764346354064222015-01-12T02:13:00.000-08:002015-01-12T02:13:08.497-08:00Saharastega moradiensis<b>Saharastega is the most primitive Temnospondyl from Gondwana related to the Edopoidea, a group that flourished during the Late Carboniferous.
<br /><br />
Saharastega lived during the Upper Permian Period and was discovered in the Moradi formation, Northwestern Niger. It is suggested that along with Nigerpeton, Saharastega is the most primitive known temnospondyli and estimated at a length of 1.8 metres (5.9 feet). The rocks entombing Saharastega suggest an aquatic habitat with evidence of an oasis.</b>
<br /><br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/temnospondyli/saharastega"><i>Saharastega moradiensis</i></a>
<dt>Authority
<dd> Sidor, O'Keefe, Damiani, Steyer, Smith, Larsson, Sereno, Ide and Maga, 2005
<dt>Meaning of generic name
<dd>Sahara, for the Sahara Desert, and stege (Greek), meaning roof
<dt>Meaning of specific name
<dd>Moradi, the formation from which the fossil was recovered, and ending -ensis (Latin), referring to place or locality or other of sth’s origin or habitat.
<dt>Size
<dd>Skull length: 45 cm , Length: .
<dt>Remains
<dd><i>Holotype</i> (MNN MOR73): nearly complete skull lacking lower jaws.
<br /><br />
<i>Referred materials:</i> [none so far?]
<dt>Age and Distribution
<dd>Horizon: Moradi Formation (Izégouandane Group, Izégouandane Basin), Upper Permian (Wuchiapingian).
<br /><br />
Locality: 20 km west of Arlit, north-central Niger.
<dt>Classification
<dd>Temnospondyli
<dt>Further Reading
<dd>Sidor, C. A., F. R. O’Keefe, R. Damiani, J.-S. Steyer, R. M. H. Smith, H. C. E. Larsson, P. C. Sereno, O. Ide, and A. Maga. 2005. Permian tetrapods from the Sahara show climate-controlled endemism in Pangaea. Nature 434:886–889.
<br /><br />
Damiani, R., C.A. Sidor, J.-S. Steyer, R.M.H. Smith, F.R. O'Keefe, H.C.E. Larsson, A. Maga, O. Ide. The vertebrate fauna of the Upper Permian of Niger—V, The primitive temnospondyl Saharastega moradiensis. Journal of Vertebrate Paleontology 26: 559-572
</dl>
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-70435788527688448672015-01-12T02:11:00.002-08:002015-01-12T02:11:09.983-08:00Nigersaurus taqueti<b><i>Nigersaurus</i> is the most common vertebrate fossil from the Nigerian Elrhaz Formation. It had hundreds of very small sharp teeth and its skull was oriented downward indicating it was a low level browser. </b>
<br /><br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/sauropoda/diplodocoidea/nigersaurus "><i>Nigersaurus taqueti</i></a>
<dt>Authority
<dd>Sereno, Beck, Dutheil, Larsson, Lyon, Moussa, Sadleir, Sidor, Varricchio, Wilson G. P. & Wilson, J. A. 1999
<dt>Meaning of generic name
<dd>Niger, for the Republique du Niger; sauros, lizard (Greek).
<dt>Meaning of specific name
<dd>In honour of French paleontologist Philippe Taquet.
<dt>Size
<dd>Length: 9 m, Skull length:
<dt>Remains
<dd><i>Holotype</i> (MNN GAD512): Partial articulated skeleton that includes a partial skull, neck, scapula, forelimbs, and hind limbs
<br /><br />
<i>Referred materials:</i> Several partial skeletons and isolated bones.
<dt>Age and Distribution
<dd>Horizon: Elrhaz Formation, Tegama Group. Lower Cretaceous (Aptian-Albian).
Locality: Gadoufaoua region, Niger.
<br /><br />
<dt>Classification
<dd>Dinosauria Saurischia Sauropodomorpha Sauropoda Diplodocoidea Rebbachisauridae
<dt>Further Reading
<dd>P. C. Sereno, A. L. Beck, D. B. Dutheil, H. C. E. Larsson, G. H. Lyon, B. Moussa, R. W. Sadleir, C. A. Sidor, D. J. Varricchio, G. P. Wilson, and J. A. Wilson. 1999. Cretaceous sauropods from the Sahara and the uneven rate of skeletal evolution among dinosaurs. Science 286:1342-1347.
<br /><br />
P. C. Sereno and J. A. Wilson. 2005. Structure and evolution of a sauropod tooth battery. In J. A. Wilson & K. A. Curry Rogers (eds.), The Sauropods: Evolution and Paleobiology. University of California Press, Berkeley 157-177.
<br /><br />
P.C. Sereno, J.A. Wilson L.M. Witmer J.A. Whitlock, A. Maga A, et al. 2007 Structural Extremes in a Cretaceous Dinosaur. PLoS ONE 2(11): e1230.
<dt>Synonyms
<dd>Rebbachisaurus tamesnensis Lapparent, 1960
</dl>
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-18976123586592949362015-01-12T02:09:00.006-08:002015-01-12T02:09:52.816-08:00Kryptops palaios<b>Kryptops palaios is a basal abelisaurid from the Early Cretaceous of Niger. Described by Sereno and Brusatte in 2008, it is known by fragmentary remains that hint to a theropod with short and broad snout and tall vertebral spines. Its length is estimated to be 6-7 m. Contemporary dinosaurs include the fish eating theropod Suchomimus and the unusual ornithopod Ouranosaurus.</b>
<br /><br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/ceratosauria/kryptops"><i>Kryptops palaios</i></a>
<dt>Authority
<dd>Sereno & Brusatte, 2008
<dt>Meaning of generic name
<dd>From Greek krypto, covered; ops, face.
<dt>Meaning of specific name
<dd>From Greek palaios, old
<dt>Size
<dd>Length: 6-7 m
<dt>Remains
<dd>Holotype (MNN GAD1): partial skeleton including a left maxilla, several partial vertebrae and ribs, and an articulated pelvic girdle and sacrum
<dt>Age and Distribution
<dd>Horizon: Elrhaz Formation. Lower Cretaceous (Aptian-Albian)
<br /><br />
Locality: “Gadoufaoua” on the western edge of the Ténéré Desert, Niger.
<dt>Classification
<dd>Dinosauria Saurischia Theropoda Ceratosauria Abelisauroidea Abelisauridae
<dt>Further Reading
<dd>P. C. Sereno and S. L. Brusatte. 2008. Basal abelisaurid and carcharodontosaurid theropods from the Lower Cretaceous Elrhaz Formation of Niger. Acta Palaeontologica Polonica 53(1):15-46.
</dl>
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-71107937912949403202015-01-12T02:09:00.001-08:002015-01-12T02:09:09.069-08:00Eocarcharia dinops<b>Eocarcharia from the Early Cretaceous of Niger is a basal Carcharodontosaurid closely related to the North American tall-spined Acrocanthosaurus. First described by Sereno and Brusatte in 2008 together with the basal ablisaur Kryptops, it is known from fragmentary skull materials and teeth. </b>
<br /><br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/carnosauria/eocarcharia"><i>Eocarcharia dinops</i></a>
<dt>Authority
<dd>Sereno & Brusatte, 2008
<dt>Meaning of generic name
<dd>Dawn Shark
<dt>Meaning of specific name
<dd>Scary face
<dt>Size
<dd>Length: ? m
<dt>Remains
<dd>Skull fragments and isolated teeth.
<dt>Age and Distribution
<dd>Gadoufaoua, Elrhaz Formation (Aptian/Albian terrestrial horizon) Niger
<dt>Classification
<dd>Dinosauria Saurischia Theropoda Carnosauria Carcharodontosauridae
<dt>Further Reading
<dd>P. C. Sereno and S. L. Brusatte. 2008. Basal abelisaurid and carcharodontosaurid theropods from the Lower Cretaceous Elrhaz Formation of Niger. Acta Palaeontologica Polonica 53(1):15-46.
</dl>
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-22412511959327517092015-01-07T06:30:00.004-08:002015-01-07T07:06:06.782-08:00Rebbachisaurus garasbae<b><i>Rebbachisaurus</i> was a large sauropod dinosaur that grew to lengths of around 20 metres. This animal had a very long neck, small head and whip like tail, which are all common features of sauropods. Rebbachisaurus lived alongside many carnivorous (meat eating) dinosaurs, like Carcharodontosaurus, Rebbachisaurus size was its main defense. One species is presently recognized, R. garasbae, the type species from Morocco. "R. tamesnensis" from Niger is considered a subjective synonym of Nigersaurus taqueti. "R. tessonei" from Argentina has been transferred to the genus Limaysaurus.</b>
<br /><br />
<dl><dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/sauropoda/diplodocoidea/rebbachisaurus"><i>Rebbachisaurus garasbae</i></a>
<dt>Authority
<dd>Lavocat, 1954
<dt>Meaning of generic name
<dd>“Rebbach lizard”
<dt>Size
<dd> Length: 20 m, Skull length:
<dt>Remains
<dd>Holotype (MNHN): postcranial elements (scapula, a humerus, caudal dorsal vetebrae)
<br /><br />
<dt>Age and Distribution
<dd>Horizon: Tegana Formation. Lower Cretaceous (Albian).
<br /><br />
Locality: Ksar-es-Souk, Morocco.
<br /><br />
<dt>Classification
<dd>Dinosauria Saurischia Sauropodomorpha Sauropoda Diplodocoidea Rebbachisauridae
<dt>Further Reading
<dd>R. Lavocat. 1954. Sur les dinosauriens du Continental Intercalaire des Kem-Kem de la Daoura [On the dinosaurs from the Continental Intercalaire of the Kem Kem of the Doura]. Comptes Rendus 19th Intenational Geological Congress, 1952 1:65-68.
<dt>Images
<dd><table><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDm9ax1iWQrUEl_yRaQikUnaLBXILMlkjdvtt5xrzQkSDw5BPdKmAiZOy6lubY1uVuh_RPzCKn4gUifzslwe7aN65U6rQaGHsmJHOrazwfylpmfpNcpehsdlP-jV_oRek7TYAdaF3Ir9LV/s1600/Rebbachisaurus_BW.jpg" imageanchor="1" ><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiDm9ax1iWQrUEl_yRaQikUnaLBXILMlkjdvtt5xrzQkSDw5BPdKmAiZOy6lubY1uVuh_RPzCKn4gUifzslwe7aN65U6rQaGHsmJHOrazwfylpmfpNcpehsdlP-jV_oRek7TYAdaF3Ir9LV/s320/Rebbachisaurus_BW.jpg" /></a>
<tr><td><a href="http://spinops.blogspot.fr/2012/06/rebbachisaurus-garasbae.html">February 25, 2009, by Nobu Tamura</a>
<tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEia5HP6MB6zrZzIh_IjCUBJ4ey6hSLBYccyF1sSs0J-bw-UIcldVCrr0Mj0cHkhkBE2hsPid9vrL5njHGUhXLO6ZE6MF_1x-khG_tPP8SK7oglwWlLJquzk0lhBuqJ-EW438_evAuI-LLIT/s1600/Rebbachisaurus_NT.jpg" imageanchor="1" ><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEia5HP6MB6zrZzIh_IjCUBJ4ey6hSLBYccyF1sSs0J-bw-UIcldVCrr0Mj0cHkhkBE2hsPid9vrL5njHGUhXLO6ZE6MF_1x-khG_tPP8SK7oglwWlLJquzk0lhBuqJ-EW438_evAuI-LLIT/s320/Rebbachisaurus_NT.jpg" /></a>
<tr><td><a href="http://spinops.blogspot.fr/2012/09/rebbachisaurus-garasbae.html">October 23, 2011, by Nobu Tamura</a>
</table>
<dt>Blog post by Nobu Tamura (images above are from his other blog Spinops
<dd> <a href="http://paleoexhibit.blogspot.com/2011/10/new-rebbachisaurid-sauropod-from-isle.html">Paleoexhibit : A New Rebbachisaurid Sauropod from the Isle of Wight.
<br />http://paleoexhibit.blogspot.com/2011/10/new-rebbachisaurid-sauropod-from-isle.html</a></dl>
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-79817005914809285292015-01-07T06:29:00.001-08:002015-01-07T06:31:05.841-08:00Nigerpeton ricqlesi<b><i>Nigerpeton</i> is a large Temnospondyl and is the last surviving representative of a group that flourished during the Late carboniferous, the Edopoids. </b>
<br /><br />
<dl><dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/temnospondyli/edopoidea/nigerpeton "><i>Nigerpeton ricqlesi</i></a>
<dt>Authority
<dd> Sidor, O'Keefe, Damiani, Steyer, Smith, Larsson, Sereno, Ide and Maga, 2005
<dt>Meaning of generic name
<dd>Niger, for the country, and herpeton (Greek), meaning crawler
<dt>Meaning of specific name
<dd> ricqlesi, named for <a href="http://en.wikipedia.org/wiki/Armand_de_Ricql%C3%A8s">Armand de Ricqlès</a>
<dt>Size
<dd> Skull length: 60 cm, Length: .
<dt>Remains
<dd> Holotype (MNN MOR69): partial skull and associated atlas vertebrae.
<br /><br />
Referred materials: MNN MOR70 (skull); MNN MOR83 (three isolated sacral neural arches with associated ribs); MNN MOR82 (partial femur).
<br /><br />
<dt>Age and Distribution
<dd> Horizon: Moradi Formation (Izégouandane Group, Izégouandane Basin), Upper Permian (Wuchiapingian).
<br /><br />
Locality: 20 km west of Arlit, north-central Niger.
<br /><br />
<dt>Classification
<dd>Temnospondyli Edopoidea
<dt>Further Reading
<dd>Sidor, C. A., F. R. O’Keefe, R. Damiani, J.-S. Steyer, R. M. H. Smith, H. C. E. Larsson, P. C. Sereno, O. Ide, and A. Maga. 2005. Permian tetrapods from the Sahara show climate-controlled endemism in Pangaea. Nature 434:886–889.</dl>Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-60227750140716821332015-01-07T06:27:00.002-08:002015-01-07T06:51:53.448-08:00Jobaria tiguidensis<b>Jobaria was a relatively large primitive sauropod dinosaur with a rather short neck; it reached lengths of around 21 m (69 ft). It was discovered in the fall of 1997 during an expedition to Niger's Sahara Desert, led by palaeontologist Paul Sereno. It was first suggested that Jobaria lived during the Early Cretaceous Period, however later studies show that it lived during the Middle Jurassic Period. A juvenile Jobaria discovered at the site in Niger yielded tooth marks on the ribs, suggesting the specimen was preyed upon, perhaps by the dinosaur Afrovenator.</b>
<br /><br />
<dl>
<dt>Name
<dd><a href=" http://www.palaeocritti.com/by-group/dinosauria/sauropoda/jobaria "><i>Jobaria tiguidensis</i></a>
<dt>Authority
<dd> Sereno, Beck, Dutheil, Larsson, Lyon, Moussa, Sadleir, Sidor, Varricchio, Wilson G. P. & Wilson, J. A. 1999
<dt>Meaning of generic name
<dd> Jobar-, Jobar (Tamacheck); -ia, pertaining to (Greek). Named after the mythical creature Jobar, to whom local Touregs had attributed the exposed bones.
<br /><br />
[Meaning they thought people had seen Jobarias, how do we know they were wrong?]
<br /><br />
<dt>Meaning of specific name
<dd>Tiguidi- (Tamacheck); -ensis, [originating ]from (Latin) after the Falaise de Tiguidi, a cliff near the base of which lie the horizons yielding all of its remains.
<dt>Size
<dd> Length: 21 m, Skull length:
<br /><br />
[Unknown, i.e. skull missing, i. e. the Touareg’s can’t be proven wrong about Jobar by exposing them to vastly different skull.]
<br /><br />
<dt>Remains
<dd> Holotype (MNN TIG3): Partial articulated skeleton including the axis, forelimbs and hind limbs, pubes, and most of the tail.
<br /><br />
Referred materials: Several partial skeletons and isolated bones.
<br /><br />
<dt>Age and Distribution
<dd> Horizon: Tiourarén Formation. Middle Jurassic (Bathonian-Oxfordian).
Locality: Tamerát, Niger.
<dt>Classification
<dd>D inosauria Saurischia Sauropodomorpha Sauropoda Diplodocoidea
<dt>Further Reading
<dd> P. C. Sereno, A. L. Beck, D. B. Dutheil, H. C. E. Larsson, G. H. Lyon, B. Moussa, R. W. Sadleir, C. A. Sidor, D. J. Varricchio, G. P. Wilson, and J. A. Wilson. 1999. Cretaceous sauropods from the Sahara and the uneven rate of skeletal evolution among dinosaurs. Science 286:1342-1347.
<dt>Synonyms
<dd><i>Rebbachisaurus tamesnensis</i> Lapparent, 1960
<dt>Image
<dd><table><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhHOSwnWRQdItRhNFnlR_rVVIZRNEGgQOpXMJlCk7dpCxBnxnh8Oa92in1eLfPgx1icHCKxYmdOAFlOBy_4AZPp8MvwM5LtYG0DtTwmfU809zVfta2zKqSXi4cXq6qb89lWrQQP8fDPMTez/s1600/Jobaria_NT.jpg" imageanchor="1" ><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhHOSwnWRQdItRhNFnlR_rVVIZRNEGgQOpXMJlCk7dpCxBnxnh8Oa92in1eLfPgx1icHCKxYmdOAFlOBy_4AZPp8MvwM5LtYG0DtTwmfU809zVfta2zKqSXi4cXq6qb89lWrQQP8fDPMTez/s320/Jobaria_NT.jpg" /></a>
<tr><td><a href="http://spinops.blogspot.fr/2013/03/jobaria-tiguidensis.html">March 2, 2013 by Nobu Tamura</a>
</table></dl>
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-89228330558311796392015-01-07T06:25:00.003-08:002015-01-07T06:49:03.138-08:00Afrovenator abakensis<b>Afrovenator is known from a single nearly complete skeleton including a partial skull from the Middle Jurassic of Niger. The Tiouraren Formation in which Afrovenator was found was originally thought to be Early Cretaceous but new studies indicate it is Middle Jurassic.</b>
<br /><br />
<dl><dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/spinosauroidea/afrovenator "><i>Afrovenator abakensis</i></a>
<dt>Authority
<dd> Sereno, Wilson, Larsson, Dutheil and Sues, 1994
<dt>Meaning of generic name
<dd>African Hunter
<dt>Meaning of specific name
<dd> “The specific name refers to Abaka, the Tuareg name for the region of Niger where the fossil was found.” Tuareg for Agadez, then?
<dt>Size
<dd> Skull length: 90 cm, Length: 9 m
<dt>Remains
<dd>Holotype (UC UBA 1): Nearly complete skeleton.
<dt>Age and Distribution
<dd> Horizon: Tiourarén Formation. Middle Jurassic (Bathonian-Oxfordian)
<br /><br />
[Formerly classified as Early Cretaceous!]
<br /><br />
Type locality: Department of Agadez, Niger
<dt>Classification
<dd>Dinosauria Saurischia Theropoda Spinosauroidea Megalosauridae
<dt>Further Reading
<dd> P. C. Sereno, J. A. Wilson, H. C. E. Larsson, D. B. Dutheil, and H.-D. Sues. 1994. Early Cretaceous dinosaurs from the Sahara. Science 266(5183):267-271.
<dt>Images
<dd><table><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0mlNTqEhlOVEuzgQXuHqpzznTbA9NhSXx2izB1uOBV9Msbh8e7d7M9Kdc81pjJj2KYv-ghkqHvsXYq2e98XtoyGr1m5ZYRQJNeobcXToP4-7PKzGPadO5iXdkn8EOQweWFlkbKHyI15Iy/s1600/Afrovenator_new_NT.jpg" imageanchor="1" ><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0mlNTqEhlOVEuzgQXuHqpzznTbA9NhSXx2izB1uOBV9Msbh8e7d7M9Kdc81pjJj2KYv-ghkqHvsXYq2e98XtoyGr1m5ZYRQJNeobcXToP4-7PKzGPadO5iXdkn8EOQweWFlkbKHyI15Iy/s320/Afrovenator_new_NT.jpg" /></a>
<tr><td><a href="http://spinops.blogspot.fr/2013/03/afrovenator-abakensis.html">By Nobu Tamura March 2, 2013</a>
<tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhIv3PLuidjyVvLEkT1Yi0Y5x3erW_gNzjhol3RBE0EUo5dWWYHG1c3bRcie-r62t5VCiuLWw9JXIQHS7Uuu9mexYwc2_R6d-kBrZZMqJUzYVAMpfxqZGw6JICNPxE1kiDBPHMlWfqLFz3X/s1600/Afrovenator_NT.jpg" imageanchor="1" ><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhIv3PLuidjyVvLEkT1Yi0Y5x3erW_gNzjhol3RBE0EUo5dWWYHG1c3bRcie-r62t5VCiuLWw9JXIQHS7Uuu9mexYwc2_R6d-kBrZZMqJUzYVAMpfxqZGw6JICNPxE1kiDBPHMlWfqLFz3X/s320/Afrovenator_NT.jpg" /></a>
<tr><td><a href="http://spinops.blogspot.fr/2012/01/afrovenator-abakensis.html">September 26, 2008, by Nobu Tamura</a>
</table></dl>
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-32300485979790894012015-01-07T06:25:00.000-08:002016-01-14T02:43:33.379-08:00Niger<a href="http://www.palaeocritti.com/by-location/niger ">Niger on Palaeocritti</a>
<br /><br />
<ul><li>?
<br /><br />
<ul><li> <a href="http://palaeocritti.blogspot.com/2015/01/afrovenator-abakensis.html">Afrovenator</a> (Theropod, Tiourarén Fm, Mi. Jur. [Bath.- Oxf.])
<li> <a href="http://palaeocritti.blogspot.com/2015/01/jobaria-tiguidensis.html">Jobaria</a> (Sauropod, Tiourarén Fm, Mi. Jur. [Bath.- Oxf.])
<li> <a href="http://palaeocritti.blogspot.com/2015/01/nigerpeton-is-large-temnospondyl-and-is.html">Nigerpeton</a> (Moradi Fm, Up. Perm. [Wuch.])
<li> <a href="http://palaeocritti.blogspot.com/2015/01/rebbachisaurus-garasbae.html">Rebbachisaurus</a> [Not really ! Link goes to Morocco!]
<li> <a href="http://palaeocritti.blogspot.com/2015/01/saharastega-moradiensis.html">Saharastega</a> (Moradi Fm, Up. Perm. [Wuch.])</ul>
<br /><br />
<li>Irhazer Group, Niger, Lower Cretaceous (Lower Berriasian-Upper Barremian)
<br /><br />
<ul><li> <a href="http://palaeocritti.blogspot.com/2016/01/name-spinostropheus-gautieri-authority.html">Spinostropheus gautieri</a> (Theropoda Ceratosauria)
<li> <a href="http://palaeocritti.blogspot.com/2016/01/spinophorosaurus-nigerensis.html">Spinophorosaurus</a> (Irhazer Gr., Mi. Jur. [Baj.-Bath.])</ul>
<br /><br />
<li>Elrhaz Formation, Tegama Group, Niger, Upper Cretaceous (Aptian-Albian)
<br /><br />
<ul><li> Anatosuchus minor (Crocodylomorpha Notosuchia)
<li> Araripesuchus wegeneri (Crocodylomorpha Notosuchia)
<li> Elrhazosaurus nigeriensis (Ornithopoda Iguanodontia Dryosauridae)
<li> Lurdusaurus arenatus (Ornithopoda Iguanodontia Iguanodontoidea)
<li> Ouranosaurus nigeriensis (Ornithopoda Iguanodontia Hadrosauroidea)
<li> <a href="http://palaeocritti.blogspot.com/2015/01/nigersaurus-taqueti.html">Nigersaurus taqueti</a> (Sauropoda Diplodocoidea Rebbachisauridae)
<li> <a href="http://palaeocritti.blogspot.com/2015/01/kryptops-palaios.html">Kryptops palaios</a> (Theropoda Ceratosauria Abelisauroidea Abelisauridae)
<li> <a href="http://palaeocritti.blogspot.com/2015/01/eocarcharia-dinops.html">Eocarcharia dinops</a> (Theropoda Carnosauria Carcharodontosauridae)
<li> <a href="http://palaeocritti.blogspot.com/2015/01/carcharodontosaurus-saharicus.html">Carcharodontosaurus saharicus</a> (Theropoda Carnosauria Carcharodontosauridae)
<li> <a href="http://palaeocritti.blogspot.com/2016/01/suchomimus-tenerensis.html">Suchomimus tenerensis</a> (Theropoda Spinosauroidea Spinosauridae)</ul>
<br /><br />
<li>Tegama Group, Niger, Lower-Upper Cretaceous (Lower Albian- Lower Cenomanian)
<br /><br />
<ul><li> Aegyptosaurus baharijensis (Sauropoda Macronaria Titanosauria)
<li> Bahariasaurus ingens (Theropoda Ceratosauria Bahariasauridae)</ul>
<br /><br />
<li>Echkar Formation, Tegama Group, Niger, Upper Cretaceous (Cenomanian)
<br /><br />
<ul><li> <a href="http://palaeocritti.blogspot.com/2016/01/kaprosuchus-saharicus.html">Kaprosuchus saharicus</a> (Crocodylomorpha Mahajungasuchidae)
<li> Laganosuchus thaumastos (Crocodylomorpha Stomatosuchidae)
<li> <a href="http://palaeocritti.blogspot.com/2016/01/rugops-primus.html">Rugops primus</a> (Theropoda Ceratosauria Abelisauroidea Abelisauridae)
<li> <a href="http://palaeocritti.blogspot.com/2016/01/carcharodontosaurus-saharicus-iguidensis.html">Carcharodontosaurus iguidensis</a> (Theropoda Carnosauria Carcharodontosauridae)</ul></ul>Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-68807413712494219712015-01-07T06:19:00.000-08:002015-01-07T06:19:28.575-08:00Algeria<a href="http://www.palaeocritti.com/by-location/Algeria">Algeria on Palaeocritti</a>
<ul><li>?
<ul><li><a href="http://palaeocritti.blogspot.fr/2015/01/carcharodontosaurus-saharicus.html">Carcharodontosaurus</a></ul>
<li>El Kohol, Algeria, Eocene
<ul><li>
Eremosuchus elkoholicus (Crocodylomorpha Sebecosuchia Baurusuchidae)</ul></ul>
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-14281224666276818992015-01-07T06:17:00.003-08:002015-01-07T06:42:46.414-08:00Carcharodontosaurus saharicus<b>Carcharodontosaurus was a large meat-eating theropod from the Early Cretaceous of Africa. Its huge skull with powerful jaw equipped with long serrated teeth make it a formidable predator.
<br /><br />
Carcharodontosaurus was originally described by French paleontologists Deperet and Savornin in 1925 as a species of Megalosaurus from fragmentary remains found in the desert of Algeria. The name Carcharodontosaurus was coined by Stromer in 1931. The original material was destroyed during WWII but additional fossils were found later. In 2007, Brusatte and Sereno described a new species from Niger, C. iguidensis.</b>
<br /><br />
<dl>
<dt>Name
<dd><a href="http://www.palaeocritti.com/by-group/dinosauria/carnosauria/carcharodontosaurus"><i>Carcharodontosaurus saharicus</i></a>
<dt>Authority
<dd> (Deperet & Savornin, 1925) Stromer, 1931
<dt>Meaning of generic name
<dd> Carcharodon (Jagged teeth) Shark Lizard
<dt>Meaning of specific name
<dd>From Sahara
<dt>Size
<dd>Length: 13.5 m
<dt>Remains
<dd>Fragmentary skull and associated postcrania.
<dt>Age and Distribution
<dd><ul><li>Baharija Formation (Cenomanian), Marsa Matruh Egypt;
<li>Tegana Formation Ksar-es-Souk Morocco;
<li>Chenini Formation "Conitental intercalaire" Medinine, Tunisia;
<li>"Continental intercalaire" (Gharyan) Lybia;
<li>"Ci" Adrar Tamenghest Wargla (Albian), Algeria;
<li>"Ci" Agadez, Niger</ul>
<dt>Classification
<dd> Dinosauria Saurischia Theropoda Carnosauria Carcharodontosauridae
<dt>Further Reading
<dd>C. Depéret and J. Savornin. 1925. Sur la découverte d'une faune de Vertébrés albiens à Timimoun (Sahara occidental) [On the discovery of a fauna of Albian vertebrates at Timimoun (western Sahara)]. Comptes Rendus des Hebdomadaires des Seances de l'Academie des Sciences à Paris 181:1108-1111.
<br /><br />
S. Brusatte and P. C. Sereno. 2007. A new species of Carcharodontosaurus (Dinosauria: Theropoda) from the Cenomanian of Niger and a revision of the genus. Journal of Vertebrate Paleontology 27(4):902-916
<dt>Synonyms
<dd><i>Megalosaurus saharicus</i> Deperet & Savornin, 1925; <i>Dryptosaurus saharicus</i> (Deperet & Savornin, 1925)
<dt>Image
<table><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgSTQYG23-foVpCvFlN5iNNqxCAwSkYi0U8JH9yZqshmZLiFckcwb8CZ9Er4uA5PAv7lRvehq1OaFS2-PUIXSLJyFoLwpVgSua-q0eo2JBnMzlfT8gMJvXXvqQbCEtbxI5y-BGvF1sklA__/s1600/Carcharodontosaurus_BW.jpg" imageanchor="1" ><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgSTQYG23-foVpCvFlN5iNNqxCAwSkYi0U8JH9yZqshmZLiFckcwb8CZ9Er4uA5PAv7lRvehq1OaFS2-PUIXSLJyFoLwpVgSua-q0eo2JBnMzlfT8gMJvXXvqQbCEtbxI5y-BGvF1sklA__/s320/Carcharodontosaurus_BW.jpg" /></a>
<tr><td>By <a href="http://spinops.blogspot.com/2012/05/carcahrodontosaurus-saharicus.html">Nobu Tamura</a>, March 6, 2007
</table></dl>
<br /><br />
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-30913113953447587882013-12-28T11:42:00.001-08:002013-12-28T11:45:14.591-08:00How do we define fossil species?<a href="http://www.palaeocritti.com/palaeo-101/how-do-we-define-fossil-species">How do we define fossil species?</a>
<br /><br />
<i>What do we currently understand by a 'species'?</i>
<br /><br />
Naming species, also known as alpha taxonomy, forms the fundamental basis and core of systematic analysis (e.g., for biodiversity, macroevolutionary and ecological studies). Since the origin of the species concept, there has been heated and continuous debate as to what exactly constitutes a species. The discovery of DNA as an evolutionary tool sparked a vigorous new line of discussion into what defines a species. Even to this day, despite a wealth of theoretical, empirical and philosophical studies, there is still a lack of consensus in the way of rigorously defining a species unit. This is not to say that there isn't a general idea of what a species is (ask any biologist or palaeontologist); in fact most people reading this will probably have a pretty good idea of what they define a species as. But there is not total agreement, not by a long shot. Furthermore, most if not all current species concepts are explicitly based on extant organisms based directly on observations and data from their every day life, and whom also just happen to provide a near-endless supply of tasty DNA. But what about fossils? Using fossils in conjunction with systematic analysis is vital, and their exclusion a violation of the principles of science (which unfortunately is all too frequent). But how do palaeontologists actually recognise and diagnose fossil species? This is a pretty serious issue, considering that DNA of fossil organisms has almost always decayed long before exhumation, and fossil remains typically only represent a biased sample of the organism it once was.
<br /><br />
<i>What are the current species concepts?</i>
<br /><br />
For biologists, the 'species problem' can be framed as: “What level of divergence (morphological, genetic, etc.) between populations constitutes independent species diagnosis?” This can be modified slightly according to whichever species concept and parameter is being applied (see below). Using DNA as a sole basis for species delimitation is fraught with issues, including but not limited to the concept of paralogy, lateral gene transfer (transfection), arbitrary delimitation protocols, lack of data (e.g., in tropical species), and often a lack of training or instrumentation (in third world countries mainly). It is currently widely accepted that a combined approach using both morphological and molecular data is the most rigorous method to assess species' validity. In spite of this, and a continuous refinement and development of technqiues, there is no single 'silver bullet' method for delimiting species (although many DNA taxonomists will try and pretend there is..). What we actually have are a series of non-independent concepts that actually apply to different stages of the process of speciation, or population divergence (de Quieroz 2007 discusses this in a most brilliant manner). Here are a couple of examples of current concepts:
<br /><br />
<ul><li><i>Biological Species Concept</i>: This is the one most people will have heard of. Species are defined by reproductive isolation, or the ability to produce fertile offspring. Obvious issues with this are if you're asexual, and how do you know if two organisms (within reason) can or cannot mate if they are not sympatric. Moreover, reproductive isolation is not always congruent with morphological or genetic divergence. Fossils cannot be diagnosed.
<br /><br />
<li><i>Phylogenetic Species Concept</i>: This refers to diagnosability based on the monophyly of a population. This invariably invokes the use of DNA. Genetic population divergence goes through three stages: polyphyly, paraphyly and finally reciprocal monophyly, giving two or more irreducible clusters of diagnosable organisms with a traceable pattern of ancestry and descent. Fossils cannot be diagnosed.
<br /><br />
<li><i>Genealogical Species Concept</i>: This is the use of multiple gene marker distributions to delimit putative species by identifying periods of complete lineage sorting. Essentially this means that the incongruence from coalescence (the point in time where gene variants unite in a gene genealogy) no longer affects delimitation. Unsurprisingly, fossils can't be diagnosed.</ul>
<br /><br />
Throughout all of these concepts, sampling remains an issue. How do you know if that your analyses are showing you is the product of a true biological signal, or just chance occurrence based on the individuals tested?
<br /><br />
A currently widely used method of delimitation is DNA barcoding. Some molecular systematists deem this as a powerful enough tool to entirely replace standard Linnaean taxonomy, although (obviously) there are numerous vocal objections. DNA barcoding operates on the assumption that there is a threshold for species delimitation based on a single gene, which is the <i>entirely</i> arbitrary 10-times-greater genetic divergence (interspecific) than intraspecificity, leading to the concept of reciprocal monophyly. It works sometimes, but is fraught with theoretical and empirical problems. (<i>I love the idea that molecular systematists will go to the tropics with the aim of identifying unique or diverse haplotypes in insects etc., by killing as many organisms as possible; “We've found a unique haplotype! We must therefore preserve this beetle at all costs!”, as the decapitated beetle floats around the dissection palate..)</i>
<br /><br />
<i>How do these concepts relate to fossils?</i>
<br /><br />
Every single one of these concepts rely on either direct observational data (e.g., sympatry for the BSC), or the use of DNA. Few modern studies rely solely on morphology to delimit species (annoyingly, seeing as it is directly coupled with behaviour, ecology etc.; DNA is just, well, DNA..). So really, with regards to fossils, in which phenotype is the only aspect preserved (and ecology etc. accordingly inferred), as well as the spatio-temporal context in which it exists, how can these concepts be applied? Well, they can't really. So what can palaeontologists do..?
<br /><br />
<i>How are fossil species delimited?</i>
<br /><br />
In principle, there are two different methods of species delimitation: a discovery-based approach, and a hypothesis-based approach. The former makes no a priori assumptions regarding the putative species in a sample, only delimiting subsequent to analysis (e.g., DNA barcoding, cladistics). The latter requires an a priori assumption of what species already exist within a sample, with the analysis being a validation test. It varies in papers as to whether a full or partial cladistic analysis is carried out (if at all) when the focus if the paper is the erection and description of a new species. By partial analysis, I simply mean that the authors observe the synapomorphies of a specific clade and see if their specimen(s) match or not. This is a pretty horrendous breach of taxonomy and cladistic methodology, as it ignores the fact the every single character placement and it's polarity is influenced by the addition of new species (in fact, this is the principal method by which cladograms are initially constructed). Full analysis is the dominantly used method, thankfully, given the accessibility of free software and relative simplicity in executing cladistic analysis (although there may be issues in obtaining and extracting previous data sets, but that's another tale too. For someone else). This leads us on to the next part.
<br /><br />
<i>Bring on Cladistics</i>
<br /><br />
Cladistics is the method that sytematists use to forge a hierarchical grouping of taxa into discrete subsets, or clades, for the inference of common ancestry between species and groups. A clade is defined by a node (or sometimes a branch) - the point of intersection of two or more branches - that represents the common ancestry and speciation event of all subsequent taxa. Each node is represented by one or more shared derived characters (synapomorphies) between all branches, and hence taxa, emanating from the node. If the taxa in question are species (i.e., terminal branches), then the minimum required number of synapomorphies to give a sister taxa relationship is one, and the minimum number of required autapomorphies (unique derived characters) to 'split' the branch into two separately recognised entities, is one. That is, cladistics can recognise discrete units, including species, on the basis of a single unique character, regardless of the size of the initial character set. There are statistical methods of assessing the strength or support of this (e.g., pseudo-replication analyses, branch decay tests), but the point remains that a species can be delimited through cladistic analysis based on the possession of a single unique character. [this is a really simple overview, there are numerous web-pages and texts out there that describe cladistic methodology in more detail; just search.]
<br /><br />
It seems that there are two main methods of delimiting fossil species: qualitatively, whereby the fossil simply looks different but the differences are not broken down into discrete characters; and quantitatively, where the species name is supported by x number of autapomorphies, and the strength or support of the diagnosis is a function of x, and is testable through cladistic methods. This is pretty much the only method available to palaeontologists given the relative paucity of fossil data. But then how many autapomorphies are required to be interpreted as a 'strong', or valid, diagnosis? And to what extent are species therefore comparable? It's a problematic issue, that I haven't actually came across much at all in the published literature. If I'm mistaken, please do point me in the right direction! What is perhaps required though, is a rigorous species concept that is directly compatible with the full range of fossil diversity, and that extant taxa can be integrated in to. More advanced methods than cladistics do exist, such as Maximum Likelihood and Bayesian analyses which rely on probability estimates and high parameter models. Unfortunately, these methodswere developed with the high quantity of data generated from DNA seuqencing in mind, and the theoretical basis for applying the models to morphological data remains elusive (not that this stops a lot of people from doing it anyway).
<br /><br />
[Picture of diverse Ammonites]
<br /><br />
With so many different forms, how do we confidently draw boundaries between different varieties?
<br /><br />
One thing to consider is that species are treated as discrete entities when these concepts are applied; is this the correct approach when really a lineage on which an organism sits is by definition, continuous? What do we gain by stamping an arbitrary and highly subjective boundary on this continuum? A method of classification. It has heuristic value in systematics, but it seems that the fundamental treatment of species as discrete units may need some consideration. Furthermore, speciation is a pretty stochastic and deterministic process, and the application of delimitation criteria must be flexible to account for the variation between lineages.
<br /><br />
What is undoubtedly required in the future is the development of a theoretical and empirical basis for species delimitation, based on all valid sources of data required. Such a holistic approach however is problematic due to the dificulties in consistency between data sets, and the difficulty in obtaining them initially in the first place. There are additional issues too such as sampling biases, which are being resolved concurrently with the research into species identification, which ultimately is requiring a global cross-disciplinary approach. In spite of the effort though, the future of species definitions in palaeontology lacks clarity, but still forms the basis for almost all research.
<br /><br />
As a final consideration, wiith respect to all of the work that has gone into validating 'species', what has been done to test the validity of higher taxonomic units, such as Family and Order, or even the Genus? It's worth pondering about what these mean in the context of systematic biology
<br /><br />
<b>Creationist comment:</b>
<br /><br />
The problem which evolutionist palaeontologists on the palaeocritti team admit being one, is a field where Creationists have done independent research, so called Baraminology. From Hebrew <i>bara</i> - create - and <i>min</i> - kind. See for instance the articles:
<br /><br />
<a href="http://creation.com/a-baraminology-tutorial-with-examples-from-the-grasses-poaceae">A baraminology tutorial with examples from the grasses (Poaceae)
<br />by Todd Charles Wood
<br />http://creation.com/a-baraminology-tutorial-with-examples-from-the-grasses-poaceae</a>
<br /><br />
<a href="http://creation.com/molecular-limits-natural-variation">Molecular limits to natural variation
<br />by Alex Williams
<br />http://creation.com/molecular-limits-natural-variation</a>
<br /><br />
A specific critique about palaeontological cladistics is the accusation of splitting species and genera too much.
<br /><br />
<a href="http://creation.com/dino-puberty-blues">Dino ‘puberty blues’ for paleontologists
<br />Dinosaur juveniles and adults wrongly labelled as separate species
<br />by David Catchpoole
<br />http://creation.com/dino-puberty-blues</a>
<br /><br />
<a href="http://creation.com/too-many-dinosaur-names">Too many dinosaur names
<br />by David Catchpoole
<br />http://creation.com/too-many-dinosaur-names</a>Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-67330816111762759972013-12-28T10:09:00.003-08:002013-12-28T11:42:25.166-08:00What can fossils tell us?<a href="http://www.palaeocritti.com/palaeo-101/what-can-fossils-tell-us">What can fossils tell us?</a>
<br /><br />
What do fossils tell us? It’s an obvious question, commonly phrased as ‘What is the point in studying fossils?’, but often can be one of the more difficult ones to answer objectively. The most prominent reason, that I’m sure a lot of people will agree with, is that we want to know what ancient and often extinct organisms looked like. This promise of discovering the unknown is what captivates people from a young age, and often motivates them in to studying fossils as a profession. From fossils, we can infer ecological aspects such as behavioural interactions, feeding strategies, and predator-prey relationships, and how these factors all changed through time. Tracking and reconstructing the co-evolution of the Earth and its biota is one of the most magical and beautiful stories ever to be told.
<br /><br />
However, fossils can provide so much more than just aesthetic pleasure. If this wasn’t so, it would make grant proposals incredibly difficult - people don’t usually like giving away money just so a fanatic can play with fossils all day. So, palaeontologists have developed numerous excuses to satisfy funding bodies, to show that studying fossils actually has some scientific value.
<br /><br />
Following are additional reasons why the study of fossils is not only awesome, but also indispensible in our understanding of biological and geological evolution.
<br /><br />
<b>Lineage Reconstruction</b>
<br /><br />
This is perhaps the most important use that fossils have for evolutionary biologists and palaeontologists. While genetic analysis might tell you about the particular history of a gene or genome, or the genetic evolution of species or populations (there are key fundamental differences between gene-trees and species-trees, something which molecular systematists miss out A LOT), they tell you virtually nothing about the phenotypic, or morphological evolution within a lineage. We don’t have many fossilised genetic markers (except in exceptional circumstances from permafrost-preserved mammoths), and thus must default to morphological analysis when tracking lineage evolution. While methods do exist for estimating and modelling the temporal evolution of species with respect to their genetic make-up, these can never provide such solid evidence as fossils can in terms of reconstructing ancient organisms, and the evolutionary trajectories leading to what we see surrounding us today.
<br /><br />
The next two points are largely based on cladistic methodology. For a nice summary of cladistics, it’s worth quickly checking the following Wikipedia entry here. Essentially, cladistic analysis is the primary method for reconstructing cladograms, or trees, that represent the systematic and hierarchical classification of organisms. Note, that cladograms are not to be confused with phylogenetic trees, in which explicit evolutionary trends are inferred (i.e., patterns of ancestor-descendant relationships).
<br /><br />
<b>Novel Extinct Morphologies</b>
<br /><br />
Cladistics is based on the analysis of characters, which are formally broken down into character states. A character is essentially an aspect of morphology which can be expressed as a number of mutually exclusive variables, or character states. This forms the basis for analysis of species’ relationships and homology assessment. An example of how this can be expressed is:
<br /><br />
<i>Maxilla, anterior process, length: shorter (0) or longer (1) than the posterior process</i> (taken from Sereno, 2007)
<br /><br />
Now, if you want to reconstruct the phylogeny of any extant group with extinct members using just living members of the group and using just morphology, then you would directly neglect the unique character combinations that fossil species exhibit. This is important because, as a general rule (there are exceptions) the more characters included in a cladistic analysis, the greater the resolution achieved. Fossils can also provide transitional morphologies between species and additional information in areas of low resolution, and therefore resolved relationships are more evolutionarily stringent. Missing out the morphological information contained within fossils constitutes a severe case of neglect, and also disregards one of the most important aspects of any evolutionary analysis: time.
<br /><br />
<b>Character Polarity</b>
<br /><br />
As shown above, characters are broken down into various character states representing variations of a particular aspect of morphology. One of the main goals of cladistic analysis is to resolve the sequence of evolutionary transformation of these particular character states. If we increase the complexity slightly to include three variables, the character becomes known as ‘multi-state’. Keeping in line with the example shown above, one possible character is:
<br /><br />
<i>Maxilla, anterior process, length: shorter (0), identical (1) or longer (2) than the posterior process</i>
<br /><br />
Note that this is a purely hypothetical example to illustrate the point. To ‘transform’ from one of these character states to an adjacent one (i.e., 0<->1 or 1<->2) it costs one ‘step’ with the implication that it costs more to transform from 0<->2, and must pass through a transitional stage, character state 1. This is known as character ordering, and represents the directionless sequence of evolutionary transformation. However, what we want to know is the direction of character state transformation, to tell if a particular character state is the derived (apomorphic) or primitive (plesiomorphic) condition. This is achieved by polarising characters, and is where fossils play their part. As fossils are explicitly related in terms of chronostratigraphic age, this can automatically impose an evolutionary trajectory on character state polarity (i.e., the older fossils have the plesiomorphic state). This can also be achieved by ‘rooting’ a cladogram through outgroup assignment, which is an a priori determination of the plesiomorphic conditions through fossils; this is actually explained quite nicely <a href="http://www.palass.org/modules.php?name=palaeo&sec=newsletter&page=103">here</a>*. The main point is that fossils perform a critical role in inferring sequences of phenotypic evolution.
<br /><br />
* <a href="http://www.palass.org/modules.php?name=palaeo&sec=newsletter&page=103">The Palaeontological Association : Cladistic characters
<br />www.palass.org/modules.php?name=palaeo&sec=newsletter&page=103</a>
<br /><br />
<b>Sampling Diversity</b>
<br /><br />
Now, one thing I’m sure palaeontologists are tired of hearing over and over is that the fossil record is biased in numerous ways (i.e., regarding sampling biases). Numerous studies have recently been undertaken to overcome these apparent biases, the most recent and critical of which is Hannisdal and Peters (2011). This paper explains how many of the patterns of fossil diversity we observe during the Phanerozoic can be explained by covariation between ancient biotas, sedimentation rates, and Earth system dynamics (e.g., ocean redox). Thus fossils, and the way in which we interpret them, are proving to be influential in how we interpret the co-evolution of, for example, biochemical and tectonic patterns, and contiguous biota assemblages.
<br /><br />
The fact remains that, yes, the fossil record is biased. But now we can compensate for and use it to nurture our understanding of geological processes in deep time. On the other hand, we have molecular systematists who consistently use the excuse of the ‘incomplete and biased’ nature of the fossil record to completely disregard the use of fossils, and assume that DNA-based analyses are adequate. This is actually pretty ironic, considering extant organisms (i.e., those we can extract DNA from) represent a single time slice containing a fraction of the total species that have existed on the Earth since life began, and is therefore the most biased sample of all. Hypocrisy, thy name is deoxyribonucleic acid. A recent example of this is Ericson (2011), in which fossils are neglected from the study entirely (with only a brief mention), thus compromising the accuracy of all results obtained (making inferences about Mesozoic palaeobiogeographic patterns without consulting the fossil record is pretty offensive). So, analysing and incorporating fossils into diversity analyses actually decreases relative sampling bias, and increases the empirical and theoretical validity of studies. Ignoring the fossil record for a biogeographical, phylogenetic, or any other evolutionary study is counter-productive, and pretty much blasphemy.
<br /><br />
<b>Breaking of Long Branches</b>
<br /><br />
Long branch attraction is a fairly common side-effect of genetic-based phylogenetic analysis, typically occurring in when invoking parsimony. It arises as the result of highly rapid divergence between multiple lineages, and due to the limitations of nucleotide substitution (i.e., four possible character states) can lead to misinterpretation of homoplastic sites (e.g., through reversals, parallelisms, or convergences of states) as homologous (orthologous) sites. This can lead to erroneous inferences about the evolutionary (i.e., topological) distances between lineages. Although using advanced modelling methods such as Maximum Likelihood or Bayesian analysis can partially resolve this issue with genetic data, fossils can also be used to ‘break up’ long branches by calibration against a particular lineage in deeper time (specifically in morphological analysis), or by providing information in areas of limited information, ultimately improving phylogenetic accuracy. This is another example of the limitations of molecular-based analyses, with analogous issues in morphological analysis being quite well understood and resolved (see Cobbett et al., 2007 for a nice discussion about including fossils in cladistic analysis).
<br /><br />
<b>Calibrating Molecular Phylogenies</b>
<br /><br />
Molecular phylogenies are becoming increasingly used to estimate divergence times of major clades and as the basis for assessing temporal dynamics in within- and between-group diversification. However, using site-substitution rates alone to estimate the temporal origin of a clade (i.e., a node) is a poor estimation, regardless of the complexity of the models employed. Therefore, fossils with a strongly supported or well-defined taxonomic status can be used to calibrate the minimum origins of a particular clade, in a strict spatio-temporal context. This bypasses several assumptions made by models, such as stochastic or constant rates of site substitution, and is therefore an invaluable tool for accurately reconstructing phylogenies. Accordingly, the integration of ‘metadata’ (such as stratigraphy, or relative or absolute ages) is essential in reconstructing accurate phylogenetic relationships. It can also reveal additional crucial factors, such as the rates of phenotypic evolution, and how particular functional characters or morphological domains covary through geological time.
<br /><br />
The above examples are just several of the more significant reasons why studying fossils is crucial, and how upon further critical analysis can yield unparalleled detail about the evolutionary history of life on Earth. It is worth noting that, although there are drawbacks and advantages to studying either the fossil record or the genetic evolution of extant taxa, it is when both are integrated that a more complete picture of global evolution emerges. Fossils are prominent in this reconstruction based on the unequivocal increased accuracy gained, but possibly at the cost of decreased resolution, due to the incomplete, patchy and biased nature of the fossil record.
<br /><br />
To finish, it’s worth quickly mention the concept of uniformitarianism: “the present is the key to the past”. This may be, in many cases of natural processes, but the past is also key to unlocking how it is the present transpired, and furthermore, in predicting future patterns of biotic diversification. To neglect the fossil record is to discard the one solid piece of evidence that we have in understanding global biotic responses to very real scenarios such as global warming.
<br /><br />
<b>Further reading</b>
<br /><br />
Butler, R. J., Benson, R. B. J., Carrano, M. T., Mannion, P. D. and Upchurch, P. (2011) Sea level, dinosaur diversity and sampling biases: investigating the ‘common cause’ hypothesis in the terrestrial realm, <i>Proceedings of the Royal Society, Biological Sciences</i>, <b>278</b>, 1165-1170
<br /><br />
Cobbett, A., Wilkinson, M. and Wills, M. A. (2007) Fossils impact as hard as living taxa in parsimony analyses of morphology, <i>Systematic Biology</i>, <b>56(5)</b>, 753-766
<br /><br />
Ericson, P. G. P. (2011) Evolution of terrestrial birds in three continents: biogeography and parallel radiations, <i>Journal of Biogeography</i>, doi:10.1111/j.1365-2699.2011.02650.x
<br /><br />
Hannisdal, B. and Peters, S. E. (2011) Phanerozoic Earth system evolution and marine biodiversity, <i>Nature</i>, <b>334</b>, 1121-1124
<br /><br />
Sereno, P. C. (2007) Logical basis for morphological characters in phylogenetic analysis, <i>Cladistics</i>, <b>23(6)</b>, 565-587
<br /><br />
<b>Creationist comment:</b>
<br /><br />
It may be no big surprise that Creationists while not ignoring the fossils, disagree very much on what they tell us. See creationist links on the page:
<br /><br />
<a href="http://palaeocritti.blogspot.com/2013/12/websites-societies-and-clubs.html">Websites, Societies and Clubs
<br />palaeocritti.blogspot.com/2013/12/websites-societies-and-clubs.html</a>Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-45113945928235266222013-12-28T09:53:00.000-08:002013-12-28T11:42:40.248-08:00How are fossils formed?<a href="http://www.palaeocritti.com/palaeo-101/how-are-fossils-formed">How are fossils formed?</a>
<br /><br />
<b>Introduction</b>
<br /><br />
The fossil record is our one and only key to a physical understanding of ancient or extinct life. Over the years a wealth of fossil remains have been uncovered, ranging from the earliest microbial life to the largest eukaryotic animals, and from isotopic signatures to fragments of DNA. These remains of dead organisms are found in two major divisions: as body fossils, where an actual specimen is preserved in some form or as trace fossils, where a particular aspect of an organism’s life is preserved, typically as trackways or burrows.
<br /><br />
<b>Processes</b>
<br /><br />
The process of preservation is termed taphonomy, and can be broken down into three main stages: necrosis, biostratinomy and diagenesis. The death of an organism, necrosis, is the initial stage in preservation, and is related to either trauma or physiology. Biostratinomy refers to the processes from death to post-mortem burial, such as transportation, bacterial decay and potential scavenging. The time taken during this stage is a critical aspect of preservation likelihood. Finally, diagenesis refers to the processes relating to the transformation of sediments into rock, and organisms into fossils. The mode of preservation leading to what we see in rocks is determined at this point, through the interaction of the surrounding sediment chemistry and the recalcitrance of various tissues. During these three stages, numerous factors act to destroy fossils, including microbial decay, predation, and a multitude of biogeochemical processes. In order for a fossil to be preserved, at some point in the taphonomic cycle, one or more of these processes must be arrested. The degree to which taphonomic breakdown is prevented is directly proportional to the degree of preservation attained.
<br /><br />
<table>
<tr valign="top">
<td>
<td>
<td><table border="1"><tr><td>Dead<br />Remains</table>
<td>Immediate<br />--><br />Burial
<td><table border="1"><tr><td>Buried<br />Remains</table>
<td>
<td>
<tr valign="top">
<td><table border="1"><tr><td>Living<br />Organisms</table>
<td>Death<br />-->
<td>
<td>
<td>
<td>Diagenesis<br />-->
<td><table border="1"><tr><td>Fossil<br />Record</table>
<tr valign="top">
<td>
<td>
<td colspan="2">Delay of Burial
<br />Biological Reworking
<td colspan="2">Delayed Burial
<td>
<tr valign="top">
<td>
<td>
<td>-->
<td><table border="1"><tr><td>Exposed Remains</table>
<td>-->
<td>
<td>
<tr valign="top">
<td>
<td>
<td colspan="4">Biostratinomy (Sedimentary Processes)
<td>
</table>
<br /><br />
<small><i>Simplified schematic of major processes during taphonomic decay of organisms</i></small>
<br /><br />
<b>Modes of Preservation</b>
<br /><br />
<i>Permineralisation or Petrifaction</i>
<br /><br />
This is the most common style whereby soluble minerals in the surrounding sediments and fluids are deposited within interstitial organic pore spaces, leading to a variety of styles of preservation. This is the most common preservation in most invertebrates, organic-walled microfossils and bones. Directly observable using various microscopic methods, this needs to be distinguished from recrystallization and dissolution processes to reconstruct the initial tissue structure.
<br /><br />
<i>Desiccation</i>
<br /><br />
The most infamous recent occurrence of desiccation-based preservation is the “dinosaur mummy” from Dakota, the aptly named, Dakota. This Upper Cretaceous hadrosaur preserves actual recrystallized tissue remains, including tendons and ligaments and the epidermal microstructure, in amazing detail. The carcass is thought to have undergone rapid burial on the periphery of a sandy river channel, enclosing it in an anoxic environment and significantly enhancing its preservation.
<br /><br />
<i>Tar</i>
<br /><br />
The La Brea Tar Pits in Los Angeles, California are renowned for the immaculate presence of a multitude of Pleistocene-age mammals. They are the products of crude oil seepage, with lighter hydrocarbon phases being siphoned off via fractionation until just sticky tar remains. The predominant hypothesis for the mass accumulations of fossils is that, once an animal was mired, it became the target for packs of predators, who ultimately met the same sticky fate as their intended prey. Little soft tissue is preserved, but the concentration of bones more than compensates. The bones are actually infused by the tar, turning them a dark brown colour. Smaller invertebrates as well as plant macro- and microfossils are also abundant here. The tar creates a completely anoxic environment in which little to no decay can occur.
<br /><br />
<i>Amber</i>
<br /><br />
Amber is the solidified remains of ancient tree sap. Organisms that are unlucky (or lucky?) enough to be preserved in amber create the most intricate and beautifully preserved fossils of all. Featuring prominently as John Hammond’s cane top in Jurassic Park, they deserve pride of place due to the exquisite detail typically preserved. The most famous deposit is the Eocene-age Baltic Amber, which has produced perfectly preserved plants, insects and even small vertebrates. Amber, like tar, entombs organisms within a completely anoxic environment, ceasing all decompositional processes.
<br /><br />
<i>Carbonisation</i>
<br /><br />
This process involves the conversion of organic tissues into a carbonaceous film or residue through either pyrolysis (i.e., thermochemical decomposition) or destructive distillation (anaerobic decomposition), usually as a result of low-grade regional metamorphism. It is the process that converts woody material into coal seams. Typical fossils found preserved like this are graptolites in shales, typically associated with scavenger-free deep-water anoxic environments, as well as marine vertebrate integument (e.g., in the Holzmaden Shale).
<br /><br />
<i>Permafrost</i>
<br /><br />
Infamous for the occasional Woolly mammoth occurrence in Alaska and Siberia. The conditions lock organisms, complete with integument and flesh, in time. DNA has even been extracted from several specimens and is incredibly useful in accurately retracing pachyderm lineages.
<br /><br />
<i>Volcanogenic</i>
<br /><br />
Classic examples where volcanic interaction has led to sites of exceptional taphonomy include the Mistaken Point Biota (Ediacaran, Newfoundland), and the Jehol Biota (Lower Cretaceous, China). The advantages of volcanogenic interaction are two-fold; firstly, they create toxic, anoxic environments, and are typically rapidly deposited creating the perfect preservational scenario. Secondly, they contain radioactive elements which can be used for high-precision radiometric dating, which can be applied by association to intercalated fossiliferous horizons. At the two mentioned sites, episodic ash falls capture and smother local fauna and flora. These are typically found interbedded with thin mudstones and shales, suggestion that they are lakeside communities mixed in with autochthonous benthic fauna. Fauna preserved associated with these ash deposits have a diagnostic opisthotonic neck posture, infamously depicted in the birds and avian theropods of the Jehol fauna, in the classic ‘angel pose’. This is possibly indicative of hypersaline or toxic waters as a cause of death.
<br /><br />
<i>Traces</i>
<br /><br />
The study of trace fossils is known as Ichnology. Trace fossils are the direct result of biological activity and have their own independent taxonomic system. This makes them extremely useful in reconstructing the behavioural palaeoecology of extinct organisms. They can represent anything from nesting sites, to anastomosing series of trackways, and can be preserved as either exogenic (on the surface of a fabric) or endogenic (made within sediments). The preservation potential for trace fossils is typically a function of grain size and depositional facies.
<br /><br />
<b>Geological Biases</b>
<br /><br />
The fossil record is an incredibly biased sample of ancient ecosystems. Scientists estimate that only 15% of the composite species in an ecosystem are typically preserved, and of these, most are those with ‘hard parts’ (e.g., shells, cuticle, bone). There are also biases reflecting the depositional environment (e.g., fluvial, lacustrine, marine, aeolian, volcanogenic), and amount of rock sampled, amongst others, which recently scientists have begun to unravel in the hopes of better determining the controls on preservation through deep geological time, and the effect this has on our understanding of the fossil record and diversity dynamics.
<br /><br />
<b>Lagerstätte</b>
<br /><br />
Occasionally, palaeontologists are fortunate enough to come across sites of exceptional preservation known as Lagerstätten (German for ‘storage place’). These represent snapshots in time, and come into two flavours: Konservat-Lagerstätten and Konzentrat-Lagerstätten. The former represents an accumulation of fossils where the detail preserved is on an incredibly intricate level, such that ‘soft parts’ are visible, even to the molecular level. The best known examples of these include the Burgess Shale (Cambrian, Canadian Rockies), and the Jehol Biota (Lower Cretaceous, China). Here, preservation of articulated elements, original labile soft tissues, unaltered mineral compositions and orientations, and even intracellular structure can be preserved, indicating the early termination of diagenetic processes or that early mineralisation sufficiently outpaced degradation. Konzentrat-Lagerstätte, on the other hand, represent unusually high concentrations of fossils, typically representing an in situ community. A classic example of this is the Morrison Formation bone bed (Late Jurassic, North America). Deposits like these typically represent mass mortality events such as flooding.
<br /><br />
<b>Recent Advances</b>
<br /><br />
Until recently, most fossils were interpreted in terms of their macroscopic preservation features. However, with technological advances such as the increasingly commonly used computed-tomography (CT) scanning and scanning-electron microscopy (SEM), sophisticated details about micro-scale preservation in numerous fossils are being recovered. Accordingly, palaeontologists are uncovering more about macro- and micro-scale physical features, as well as physiological, cellular and even sub-cellular processes.
<br /><br />
<b>Further Reading</b>
<br /><br />
Allison, P. A. and Bottjer, D. J. (2011) <i>Taphonomy: process and bias through time<i></i></i>, second edition, New York: Springer
<br /><br />
Nudds, J. and Selden, P. (2008) Fossil-Lagerstätten, <i>Geology Today</i>, <b>24(4),</b>153-158
<br /><br />
Schweitzer, M. H., Avci, R., Collier, T. and Goodwin, M. B. (2008) Microscopic, chemical and molecular methods for examining fossil preservation, <i>Comptes Rendus Palevol,</i> <b>7</b>, 159-184
<br /><br />
Upchurch, P., Mannion, P. D., Benson, R. B. J., Butler, R. J. & Carrano, M. T. (2011, in press). Geological and anthropogenic controls on the sampling of the terrestrial fossil record: a case study from the Dinosauria. In: <i>Comparing the Geological and Fossil Records: Implications for Biodiversity Studies</i>, McGowan, A. J. and Smith, A. B. (eds). <i>Geological Society, London, Special Publication</i> <b>358</b>: 209-240
<br /><br />
<b>Creationist Comment:</b>
<br /><br />
Many fossils world wide testifying to rapid burial constitute one line of argument in favour of the Flood.Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-28339609146632263942013-12-28T08:58:00.002-08:002013-12-28T11:42:53.330-08:00Websites, Societies and Clubs<a href="http://www.palaeocritti.com/palaeo-101/collecting-fossils/websites-for-identification-and-fossil-hunting-localities">Websites for identification and fossil hunting localities
<br /><br />
Some Palaeontological Websites...</a>
<br /><br />
There are thousands of websites dealing with rocks and fossils, and it can be very difficult for anyone new to the subject to know which ones are factually correct and which ones are misleading. The phrase ‘don’t believe everything you read on the web’ is very true!
<br /><br />
Listed below are some very good websites for children and adults alike who are wanting to get involved in palaeontology. Some of the websites are based all around good fossil hunting sites etc...
<br /><br />
<table><tr><td><a href="http://www.rockwatch.org.uk">www.rockwatch.org.uk</a>
<td>Children’s club for rocks and fossils
<tr><td><a href="http://www.nhm.ac.uk/nature-online/earth/fossils">www.nhm.ac.uk/nature-online/earth/fossils</a>
<td>Natural History Museum’s portal for fossils
<tr><td><a href="http://www.whitbymuseum.org.uk">www.whitbymuseum.org.uk</a>
<td>Great Museum for fossil collections and reference
<tr><td><a href="http://www.oum.ox.ac.uk/thezone/fossils">www.oum.ox.ac.uk/thezone/fossils</a>
<td>Oxford Universities fossil portal (great for adults and children)
<tr><td><a href="http://www.sedgwickmuseum.org">www.sedgwickmuseum.org</a>
<td>Cambridge based museum (great for adults and children)
<tr><td><a href="http://www.dinocoast.org.uk">www.dinocoast.org.uk</a>
<td>All about East Yorkshire coast geology and fossils
<tr><td><a href="http://www.open2.net/fossildetectives/index.html">www.open2.net/fossildetectives/index.html</a>
<td rowspan="2">the British Geological Survey. Information, advice and research facilities
<tr><td><a href="http://www.bgs.ac.uk">www.bgs.ac.uk</a>
<tr><td><a href="http://www.zoomdinosaurs.com">www.zoomdinosaurs.com</a>
<td>a great general site about dinosaurs
<tr><td><a href="http://www.museumoftheearth.org">www.museumoftheearth.org</a>
<td>website of the Palaeontological Research Institution
<tr><td><a href="http://www.discoveringfossils.co.uk">www.discoveringfossils.co.uk</a>
<td>portal for everything you need to know about fossils
<tr><td><a href="http://www.ukfossils.co.uk">www.ukfossils.co.uk</a>
<td>portal for everything you need to know about fossils</table>
<br /><br />
<a href="http://www.palaeocritti.com/palaeo-101/collecting-fossils/societies-and-clubs">Societies and Clubs</a>
<br /><br />
[T]here are many societies and clubs in the world dedicated to palaeontology and all that surrounds the prehistoric world, here are some well known sites you can join...
<br /><br />
<ul><li>List 1:
<ul><li>1, <a href="http://www.rockwatch.org.uk">Rock Watch (Children’s club) -
<br />www.rockwatch.org.uk</a>
<br /><br />
Rock Watch is an internet subscription club for children interested in rocks and fossils</ul>
<br /><br />
<li>List 2:
<br /><br />
<ul><li>1, <a href="http://www.yorksgeolsoc.org.uk">The Yorkshire Geological Society -
www.yorksgeolsoc.org.uk</a>
<li>2, <a href="http://www.hullgeolsoc.org.uk">Hull Geological Society -
<br />www.hullgeolsoc.org.uk</a>
<br /><br />
<li>3, <a href="http://www.leedsgeolassoc.freeserve.co.uk">Leeds Geological Association -
<br />www.leedsgeolassoc.freeserve.co.uk</a>
<br /><br />
These three Geological societies are the perfect place for beginners and enthusiasts to get involved in the world of geology and palaeontology. There is many more clubs around the U.K. which have similar interests this is just a select few.</ul>
<br /><br />
<li>List 3:
<br /><br />
<ul><li>1, <a href="http://www.vertpaleo.org">The Society of Vertebrate Palaeontology -
<br />www.vertpaleo.org</a>
<br /><br />
<li>2, <a href="http://www.palass.org">The Palaeontological Association -
<br />www.palass.org</a>
<br /><br />
<li>3, <a href="http://www.aaps.net">The Association of Applied Palaeontological Sciences -
<br />www.aaps.net</a>
<br /><br />
<li>4, <a href="http://www.paleosoc.org">The Palaeontological Society -
<br />www.paleosoc.org</a>
<br /><br />
These are major (International) scholarly societies, and are really only recommended for the serious enthusiast, who has a developed knowledge of the subject.</ul></ul>
<br /><br />
<b>And Creationism?</b>
<br /><br />
[Added by Hans-Georg Lundahl, probably including some of the reasons the palaeocritti team before recommending links above wrote: <i>"The phrase ‘don’t believe everything you read on the web’ is very true!"</i>]
<br /><br />
<a href="http://www.daylightorigins.com/">Daylight Origins Society
<br />Catholic creation & origins science
<br />www.daylightorigins.com/</a>
<br /><br />
<a href="http://www.kolbecenter.org/">The Kolbe Center
<br />for the study of Creation
<br />www.kolbecenter.org/</a>
<br /><br />
<a href="http://magisterialfundies.blogspot.com">Magisterial Fundies
<br />magisterialfundies.blogspot.com</a>
<br /><br />
<a href="http://creation.com/">Creation Ministries International
<br />creation.com/</a>
<br /><br />
<a href="http://www.icr.org/">Institute for Creation Research
<br />www.icr.org/</a>
<br /><br />
<a href="http://www.biblicalgeology.net/">Tas Walker's Biblical Geology
<br /><br />www.biblicalgeology.net/</a>
<br /><br />
AND:
<br /><br />
<a href="http://creavsevolu.blogspot.com">Creation vs. Evolution
<br />[My own]
<br />creavsevolu.blogspot.com</a>
<br /><br />
Which has taken a palaeontological turn with messages like:
<br /><br />
<a href="http://creavsevolu.blogspot.com/2013/12/three-meanings-of-chronological-labels.html">Three Meanings of Chronological Labels
<br />creavsevolu.blogspot.com/2013/12/three-meanings-of-chronological-labels.html</a>
<br /><br />
and the series starting with
<br /><br />
<a href="http://creavsevolu.blogspot.com/2013/11/how-do-fossils-superpose.html">How do Fossils Superpose?
<br />creavsevolu.blogspot.com/2013/11/how-do-fossils-superpose.html</a>
<br /><br />
I do not know which of the Creationist sites which will be most relevant for a Christian Creationist specifically interested in Palaeontology. I intend to make my own blog a runner up. And that is why I came across the site ...
<br /><br />
<a href="http://www.palaeocritti.com">palaeocritti
<br />www.palaeocritti.com</a>
<br /><br />
... in the first place. Which to my dismay will be closing in 2016, which is the reason I was given permission to make a back-up blog by Nobu Tamura.
<br /><br />
Merry Christmas to the original team, especially Nobu Tamura,
<br /><br />
from
<br />Hans-Georg LundahlHans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0tag:blogger.com,1999:blog-9162565542082203058.post-15728624409523071322013-12-28T03:17:00.001-08:002013-12-28T11:43:07.446-08:00General Books on Palaeontology & Fossil identification books<a href="http://www.palaeocritti.com/palaeo-101/collecting-fossils/general-fossil-books">Palaeontological Books</a>
<br /><br />
<i>So you have decided you would like to learn more about the exciting world of Palaeontology?</i>
<br /><br />
Well these books listed here will give you a good insight into palaeontology as a whole and explain some of the key attributes of the subject. All of the books are full of insightful informative work and brilliant photographs and artwork...
<br /><br />
<b>For beginners:</b>
<br /><br />
<ul><li>1, Encyclopaedia of Dinosaurs and Prehistoric Life, by David Lambert, Darren Naish and Elizabeth Wyse
<li>2, Fossil Detectives, Discovering Prehistoric Britain, by Hermione Cockburn and Douglas Palmer
<li>3, The Complete Guide to Prehistoric Life, by Tim Haines
<li>4, Complete Encyclopedia of Fossils, by Martin Ivanov</ul>
<br /><br />
For the initiated:
<br /><br />
<ul><li>1, Fossil Plants, by Paul Kenrick and Paul Davis
<li>2, Fossil Invertebrates, by Paul D Taylor and David N Lewis
<li>3, Fossils: the Key to the Past, by Richard Fortey
<li>4, Atlas of the Prehistoric World, by Douglas Palmer</ul>
<br /><br />
+ (Of course) many, many more
<br /><br />
<a href="http://www.palaeocritti.com/palaeo-101/collecting-fossils/fossil-identification-books">Fossil identification books</a>
<br /><br />
<i>So you have found a fossil and you would like to identify it?</i>
<br /><br />
Listed below are only a few books on identification of fossils but believe me their are thousands out there! The reason i have chosen these books is to help you get a good understanding of some of the fossils and how to correctly identify them, plus many of these books have wonderful illustrations and images.
<br /><br />
For the beginner:
<br /><br />
<ul><li>1, Fossils (DK Handbook), by David Ward
<li>2, Fossils (Collins GEM), by Douglas Palmer
<li>3, Fossils A Photographic Field Guide, by Chris and Helen Pellant
<li>4, Fossils of the Whitby Coast: A Photographic Guide, by Dean R. Lomax</ul>
<br /><br />
For the initiated:
<br /><br />
<ul><li>1, British Palaeozoic Fossils, British Museum (Natural History)
<li>2, British Mesozoic Fossils, British Museum (Natural History)
<li>3, British Cenozoic Fossils, British Museum (Natural History)</ul>
<br /><br />
+ (Of course many, many more)
Hans Georg Lundahlhttp://www.blogger.com/profile/01055583255516264955noreply@blogger.com0