Saturday, 28 December 2013

How do we define fossil species?

How do we define fossil species?

What do we currently understand by a 'species'?

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.

What are the current species concepts?

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:

  • Biological Species Concept: 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.

  • Phylogenetic Species Concept: 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.

  • Genealogical Species Concept: 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.

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?

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 entirely 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 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..)

How do these concepts relate to fossils?

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..?

How are fossil species delimited?

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.

Bring on Cladistics

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.]

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).

[Picture of diverse Ammonites]

With so many different forms, how do we confidently draw boundaries between different varieties?

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.

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.

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

Creationist comment:

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 bara - create - and min - kind. See for instance the articles:

A baraminology tutorial with examples from the grasses (Poaceae)
by Todd Charles Wood

Molecular limits to natural variation
by Alex Williams

A specific critique about palaeontological cladistics is the accusation of splitting species and genera too much.

Dino ‘puberty blues’ for paleontologists
Dinosaur juveniles and adults wrongly labelled as separate species
by David Catchpoole

Too many dinosaur names
by David Catchpoole

What can fossils tell us?

What can fossils tell us?

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.

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.

Following are additional reasons why the study of fossils is not only awesome, but also indispensible in our understanding of biological and geological evolution.

Lineage Reconstruction

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.

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).

Novel Extinct Morphologies

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:

Maxilla, anterior process, length: shorter (0) or longer (1) than the posterior process (taken from Sereno, 2007)

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.

Character Polarity

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:

Maxilla, anterior process, length: shorter (0), identical (1) or longer (2) than the posterior process

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 here*. The main point is that fossils perform a critical role in inferring sequences of phenotypic evolution.

* The Palaeontological Association : Cladistic characters

Sampling Diversity

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.

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.

Breaking of Long Branches

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).

Calibrating Molecular Phylogenies

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.

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.

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.

Further reading

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, Proceedings of the Royal Society, Biological Sciences, 278, 1165-1170

Cobbett, A., Wilkinson, M. and Wills, M. A. (2007) Fossils impact as hard as living taxa in parsimony analyses of morphology, Systematic Biology, 56(5), 753-766

Ericson, P. G. P. (2011) Evolution of terrestrial birds in three continents: biogeography and parallel radiations, Journal of Biogeography, doi:10.1111/j.1365-2699.2011.02650.x

Hannisdal, B. and Peters, S. E. (2011) Phanerozoic Earth system evolution and marine biodiversity, Nature, 334, 1121-1124

Sereno, P. C. (2007) Logical basis for morphological characters in phylogenetic analysis, Cladistics, 23(6), 565-587

Creationist comment:

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:

Websites, Societies and Clubs

How are fossils formed?

How are fossils formed?


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.


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.

    Delay of Burial
Biological Reworking
Delayed Burial  
Exposed Remains
    Biostratinomy (Sedimentary Processes)  

Simplified schematic of major processes during taphonomic decay of organisms

Modes of Preservation

Permineralisation or Petrifaction

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.


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.


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.


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.


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).


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.


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.


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.

Geological Biases

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.


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.

Recent Advances

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.

Further Reading

Allison, P. A. and Bottjer, D. J. (2011) Taphonomy: process and bias through time, second edition, New York: Springer

Nudds, J. and Selden, P. (2008) Fossil-Lagerstätten, Geology Today, 24(4),153-158

Schweitzer, M. H., Avci, R., Collier, T. and Goodwin, M. B. (2008) Microscopic, chemical and molecular methods for examining fossil preservation, Comptes Rendus Palevol, 7, 159-184

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: Comparing the Geological and Fossil Records: Implications for Biodiversity Studies, McGowan, A. J. and Smith, A. B. (eds). Geological Society, London, Special Publication 358: 209-240

Creationist Comment:

Many fossils world wide testifying to rapid burial constitute one line of argument in favour of the Flood.

Websites, Societies and Clubs

Websites for identification and fossil hunting localities

Some Palaeontological Websites...

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!

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... Children’s club for rocks and fossils Natural History Museum’s portal for fossils Great Museum for fossil collections and reference Oxford Universities fossil portal (great for adults and children) Cambridge based museum (great for adults and children) All about East Yorkshire coast geology and fossils the British Geological Survey. Information, advice and research facilities a great general site about dinosaurs website of the Palaeontological Research Institution portal for everything you need to know about fossils portal for everything you need to know about fossils

Societies and Clubs

[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...

And Creationism?

[Added by Hans-Georg Lundahl, probably including some of the reasons the palaeocritti team before recommending links above wrote: "The phrase ‘don’t believe everything you read on the web’ is very true!"]

Daylight Origins Society
Catholic creation & origins science

The Kolbe Center
for the study of Creation

Magisterial Fundies

Creation Ministries International

Institute for Creation Research

Tas Walker's Biblical Geology


Creation vs. Evolution
[My own]

Which has taken a palaeontological turn with messages like:

Three Meanings of Chronological Labels

and the series starting with

How do Fossils Superpose?

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 ...


... 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.

Merry Christmas to the original team, especially Nobu Tamura,

Hans-Georg Lundahl

General Books on Palaeontology & Fossil identification books

Palaeontological Books

So you have decided you would like to learn more about the exciting world of Palaeontology?

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...

For beginners:

  • 1, Encyclopaedia of Dinosaurs and Prehistoric Life, by David Lambert, Darren Naish and Elizabeth Wyse
  • 2, Fossil Detectives, Discovering Prehistoric Britain, by Hermione Cockburn and Douglas Palmer
  • 3, The Complete Guide to Prehistoric Life, by Tim Haines
  • 4, Complete Encyclopedia of Fossils, by Martin Ivanov

For the initiated:

  • 1, Fossil Plants, by Paul Kenrick and Paul Davis
  • 2, Fossil Invertebrates, by Paul D Taylor and David N Lewis
  • 3, Fossils: the Key to the Past, by Richard Fortey
  • 4, Atlas of the Prehistoric World, by Douglas Palmer

+ (Of course) many, many more

Fossil identification books

So you have found a fossil and you would like to identify it?

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.

For the beginner:

  • 1, Fossils (DK Handbook), by David Ward
  • 2, Fossils (Collins GEM), by Douglas Palmer
  • 3, Fossils A Photographic Field Guide, by Chris and Helen Pellant
  • 4, Fossils of the Whitby Coast: A Photographic Guide, by Dean R. Lomax

For the initiated:

  • 1, British Palaeozoic Fossils, British Museum (Natural History)
  • 2, British Mesozoic Fossils, British Museum (Natural History)
  • 3, British Cenozoic Fossils, British Museum (Natural History)

+ (Of course many, many more)

Cetiosaurus oxoniensis

Cetiosaurus (meaning “whale lizard”) was a large sauropod dinosaur from the mid to late Jurassic Period. It had a long neck with a small head and an extremely long tail, it was walking on all fours probably shaking the earth with every step. It is estimated that an adult Cetiosaurus may have weighed up to around 25 tons. Like all sauropods, it was an herbivore. This dinosaur would most likely have lived together in herds, footprints of sauropod dinosaurs herding together have been found on coastlines across the world, even possibly at Saltwick Bay, Whitby [Scroll down, alas no image as yet].

Did you know?

Cetiosaurus was the very first sauropod to be discovered, and is the best known sauropod dinosaur from England.

Cetiosaurus was first discovered in 1841 on the Isle of Wight and named by Sir Richard Owen. He first thought the bones must belong to some sort of large marine reptile, thus the name. Several more specimens of Cetiosaurus were discovered in the late 1840s and an almost complete specimen was discovered in 1868. Thomas Huxley eventually recognized Cetiosaurus as a dinosaur after the magnificent find in 1869. Several isolated bones from a dinosaur were discovered in the late 18th century on the North East coast at Whitby which possibly belong to Cetiosaurus. Four separate species are known from Cetiosaurus including the most famous Cetiosaurus oxoniensis, which was discovered at Rutland in Oxfordshire. This specimen was from the Bajocian stage of the Jurassic Period.

Cetiosaurus oxoniensis
Phillips, 1871
Meaning of generic name
Whale lizard
Meaning of specific name
from Oxford
Length: 18 m
Vertebrae, ribs and limb fragments
Age and Distribution
(Bajocian), Isle of Wight, UK
Dinosauria Saurischia Sauropoda Cetiosauridae
Further Reading
Upchurch P & Martin J (2003). "The Anatomy and Taxonomy of Cetiosaurus (Saurischia, Sauropoda) from the Middle Jurassic of England". Journal of Vertebrate Palaeontology 23 (1): 208–231.
Image by Nobu Tamura (click to enlarge)
Cetiosaurus oxoniensis, May 4, 2009:

Collecting fossils - in general and at Saltwick Bay, Whitby, England

On site:

Getting Involved!

Do you know where to find the rocks which contain fossils, how to recognise them, or how to crack them, whether what you are doing is legal, whether the location is safe, what you’ve found if you do stumble across something or what to do with it once you have it?

Let’s say you just go to a beach and pick up a fossil, pop it in your rucksack and take it home. Imagine, a few weeks or months later, that dusty old fossil on a shelf at home, forgotten and just another bit of clutter…

But what if you’d done a bit of research before you went fossil hunting, found out about the geology of the site and which fossils you might find there? What if you were armed with a bit of knowledge and something to identify your finds? What if you’d recorded where you found it, the type of rock it came from and what other fossils were visible nearby?

Think about it… when you find a fossil, you’re the first person to have held it. Its been buried for millions of years, a piece of a big prehistoric puzzle that can give us a glimpse of planet earth when it was populated with all kinds of fascinating plants and animals, that are now extinct! RECORD and RESEARCH what you find and you are piecing together the jigsaw.

This is the difference between just finding a fossil and taking it home, and recording and researching it. Instead of having one puzzling piece of a jigsaw you have the complete finished picture!

Fossil hunting is a skill that takes time and patience to acquire!

There’s much more to fossil hunting than just hitting rocks with a hammer and hoping for the best!

There’s no easy way to tell you how to recognise a fossil, let alone how to crack it from the rock it’s in. The best way is to find someone who knows how to do it and get them to show you. You could do this by joining a club or society or by going on a reputable fossil hunting tour.

Go out with an open mind and expect the unexpected!

Where can I find a fossil?!?

They can be found all over the world if you look in the right places. The less visited places are where you are likely to find the more interesting fossils (maybe even something completely new). Keep your eyes open as you’re walking around on hills, along streams and on beaches where layers of rock are exposed. All sorts of interesting things can turn up.

What equipment will I need?

The basic fossil collector’s field kit consists of the following items:

  • Suitable clothing and footwear (depending on the location and weather).
  • A hard hat .
  • Gloves.
  • Safety goggles.
  • A geological hammer and/or lump hammer and stone chisel.
  • A hand lens or magnifying glass.
  • A notepad and pen/pencil.
  • Camera.
  • Plastic finds bags and bubble wrap.
  • A bag to carry all your equipment and your fossil finds.

Here are some top tips on how to get more involved in palaeontology:

Visit museums and look at there displays and collections – this is a great way to discover what fossils are found in particular locations, how they relate to the local geology (the environment they lived in), and how to identify them. Some museums will also have geologists and/or palaeontologists, who can help you, learn more.

Read a few books – books are a great way of improving your general knowledge of the subject and giving you a better understanding of what you will see in a museum or out and about at fossil sites. There are books to suite all ages and levels of expertise, which will do everything from helping you to identify the geology that particular fossils are found in and their locations, to how to identify one fossil from another.

Join a society or club – There are lots of local geological societies who cater for all ages and levels of expertise. This is a great way to get actively involved in the subject, go out on field trips and meet other amateurs or professionals, and learn from them and share knowledge.

Go out fossil hunting – This is the best way to engage with the subject and learn more, it’s also one of the most fun parts of palaeontology. However BEFORE you do this you SHOULD read the ‘Getting actively involved panel’ which will explain how to go about fossil hunting.

Fossil hunting at Saltwick Bay, Whitby, United Kingdom

As you discovered on the previous page [above on this blog] fossil hunting is a skill which can only be learned through many hours of searching for fossils and training your eyes to spot unusual and strange shapes and structures.

Saltwick Bay near Whitby in the U.K. is known for hundreds of fossil finds, some include a huge variety of ammonites including, Hildoceras, Dactylioceras and Harpoceras. Several unusual fossil finds occur all along the Yorkshire coast and at Saltwick Bay, some major finds have included marine reptile remains such as crocodilians, plesiosaurs and ichthyosaurs, dinosaur footprints and plants have also been discovered from the terrestrial (land) deposits.

[Images have been removed from palaeocritti site (and were not Nobu Tamura's property anyway) but descriptions are:]

  • Image above: Saltwick Bay looking east (right-hand side).
  • Looking west from the top of Saltwick Bay (left-hand side).
  • Peter Robinson of the Doncaster Museum and Art Gallery is fully equipped for fossil hunting. The tide is just on its way out, always remember to check the tide times when fossil hunting along the coast.
  • Dean Lomax looks for fossils in the shingle that had been washed around and deposited on the foreshore. The shingle is the best place to look for, and find fossils.
  • John Robinson, an avid fossil collector searches for fossils washed underneath the cliff face. Note that he is wearing a helmet.
  • A large cliff fall at Saltwick Bay (left-hand side) will obviously uncover several interesting fossils. Remember! DO NOT run up the newly formed talus pile as it is continually breaking up, and you never know when the next lot will come crashing down. Wait for the tide to do its job and wash the newly formed pile around, the fossils will be easier to find and much, much safer!
  • Dean is resting on a huge slab which has at least two individual dinosaur footprints represented. The specimen dates to the Aalenian Stage of the Jurassic Period. Note the large three toed footprint underneath his right knee probably from a theropod or ornithopod dinosaur. The other is much harder to spot, it is in the centre of the picture at the bottom much more of a squashed rounded shape, probably from a sauropod perhaps Cetiosaurus?.

Want to find out even more? Click any of the links below:

Creationist Warning:

If you get into the clubs and societies and go fossil hunting, you can expect to get involved with lots of Evolutionists and of being a minority of one. A situation I am familiar with, and I know the strain./HGL

Institution abbreviations

On Palaeocritti original site:

AMF: Australian Museum, Fossil, Sydney, Australia
AMNH: American Museum of Natural History, U.S.A.
ANSP: Academy of Natural Sciences, Philadelphia, PA, U.S.A.

BMNH: The Natural History Museum, London,UK
BP: Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, Johannesburg, South Africa

CGP: Council for Geosciences (formerly the Geological Survey of South Africa), Pretoria, South Africa
CM: Cincinnati Museum collection
CMNH: Cleveland Museum of Natural History, Cleveland, U.S.A.
CPC: Commonwealth Palaeontological Collection, Canberra, Australia

DMAG: Doncaster Museum & Art Gallery, U.K.

FMNH: Field Museum of Natural History, Chicago, Illinois, U.S.A.

GLAHM: Hunterian Museum, Glasgow, Scotland, UK
GSE: Geological Survey of Scotland, Edinburgh, Scotland, UK
GSQ: Department of Mines, Geological Survey of Queensland collection (now part of QMF), Australia

HMBM: Humboldt Museum, Berlin; IPM, Institut fu¨r Pala¨ontologie Mu¨nchen, Germany
HMG: Hancock Museum, Newcastle-upon-Tyne

LEICS: New Walk Museum & Art Gallery, Leicester, UK
LTU: La Trobe University

MCZ: Museum of Comparative Zoology, Harvard University, Cambridge, Mass., U.S.A.
MGUH: Geological Museum of the University of Copenhagen, Denmark
MNHN: Musée National d’Histoire Naturelle, Paris, France

NBM: New Brunswick, Museum, Saint John
NEWHMG: Hancock Museum, Newcastle-upon-Tyne, Geology
NHM P: The Natural History Museum, London, Palaeontology, England, UK
NMING: National Museum of Eire ⁄ Ireland, Dublin
NMQR: National Museum, Bloemfontein, South Africa
NMS: National Museum of Scotland, Edinburgh, UK
NMS (RSM): National Museums of Scotland, Royal Scottish Museum, Edinburgh, UK
NMVP: Museum of Victoria, Palaeontology, Melbourne, Australia
NSMNH: Nova Scotia Museum of Natural History, Canada

OUSM: University of Oklahoma, Stovall Museum, Oklahoma, U.S.A.

PIN: Paleontological Institute, Moscow, Russia

QMF: Queensland Museum Fossil, Brisbane, Australia

RJ: Roger Jones coll., London, England, UK
RM: Redpath Museum, McGill University, Montreal, Canada
ROM: Royal Ontario Museum of Palaeontology, Toronto, Canada

SAM: South African Museum, Cape Town, South Africa
SM: Sedgwick Museum, Cambridge University
SMP; State Museum of Philadelphia
SPW; Stanley P. Wood collection, Mr Wood’s Fossils, Cowgatehead, Edinburgh

TCD; Trinity College, Dublin, Geology Collection
TMM; Texas Memorial Museum, University of Texas, Austin, Texas, U.S.A.

UC; University of Chicago, U.S.A.
UC: University of Cincinnati, U. S. A.
UCLA VP: University of California, Los Angeles, Vertebrate Paleontology, California, U.S.A.
UK: University of Kansas, Lawrence, Kansas, U.S.A.
UQ: University of Queensland.

WAM: Western Australian Museum, Perth, Australia
WDC: Wyoming Dinosaur Center, Wyoming, U.S.A.

"Creationist suspicion" - These are the abbreviations to which specimen numbers (holotypes, paratypes and referred) are attached?

Thursday, 26 December 2013

Istiodactylus latidens

Originally described by Seeley in 1901 and thought to be a bird, Istiodactylus has been recognized as a pterosaur and changed its name from Ornithodesmus because the original material used for the description also contained some theropod dinosaur bones. Istiodactylus lived during the Early Cretaceous of what is now England. It had a flat rounded shape beak with an unusually large naso-antorbital fenestra which is occupying most of the snout. Istiodactylus and its relatives could had lived on a diet of fish; however, given the general distribution of istiodactylids, they would have to be inland piscivores rather like modern pelicans. There have also been some proposition that they were actually scavengers, as they were more efficient walkers than other ornithocheiroids and had teeth similar to those of some sharks.

Istiodactylus latidens
(Seeley, 1901) Howse, Milner & Martill, 2001
Meaning of generic name
Sail Finger
Meaning of specific name
broad tooth
Wingspan: 4-5 m, Skull length: 560 mm
Four partial skeletons.
Age and Distribution
Early Cretaceous (Barremian) Vectis Formation of the Isle of Wight, England, UK.
Pterosauria Pterodactyloidea Ornithocheiroidea Istiodactylidae
Further Reading
Hooley, R. W., 1913, On the skeleton of Ornithodesmus latidens. An ornithosaur from the Wealden shales of Atherfield (Isle of Wight), Quarterly Journal of the Geological Society, 69: 372-421.

Howse, S. C. B., Milner A. R., and Martill, D. M., 2001, Pterosaurs. Pp. 324-335 in: Martill, D. M. and Naish, D., eds. Dinosaurs of the Isle of Wight, The Palaeontological Association.
Ornithodesmus latidens Seeley, 1901


Metriorhynchus (meaning “moderate snout”) was an active predator probably preying on fish and smaller marine creatures, it likely spent most if not all of its life in the open ocean. It is estimated that Metriorhynchus may have been able to reach lengths of around 10 feet (3 metres).

It was first discovered in Germany, 1830. Remains of Metriorhynchus have been discovered at various localities across Europe and South America. In the U.K. specimens have been recovered from the famous Oxford clay and is composed of up to 5 different species, with M. superciliosus from the Callovian-Oxfordian, and M. durobrivensis from the Callovian, being the best known. Metriorhynchus also appeared in the Kimmeridgian.

von Meyer, 1830
Meaning of generic name
Moderate Snout
Meaning of specific names
durobrivensis=from Durobrivae. = Latin name for Roman period of Rochester (Latin later Roffa) Superciliosus=browey (supercilium=eye-brow, cilium=eye-lash)
Length: 3 m
Several isolated bones, several complete skeletons
Age and Distribution
Callovian - Kimmeridgian, Europe, South America
Paracrocodylomorpha, Diapsida, Mesoeucrocodylia, Thatlattosuchia, Metriorhynchidae
Further Reading
Andrews CW. 1913. A descriptive catalogue of the marine reptiles of the Oxford Clay, Part Two. London: British Museum (Natural History), 206 pp.
Suchodus Lydekker, 1890 Purranisaurus Rusconi, 1948
Images by Nobu Tamura (click to enlarge)
Metriorhynchus superciliosus, January 15, 2007:
Same, December 7, 2008:

Parexus recurvus

Parexus is an extinct genus of acanthodian fish, the acanthodians are often referred to as ‘spiny sharks’ despite the fact acanthodians evolved perhaps 50 million years earlier than sharks. They share several features with bony fish and cartilaginous fish; they often have spines supporting their fins.

Parexus is recognised by its obscenely large anterior dorsal fin spine. Several fossils have been discovered from the Early (Lower) Devonian Period of Tillywhandland, Scotland. Besides P. recurvus, a second species, P. falcatus Powrie, 1870 also from Scotland has also been described.

Parexus recurvus
Agassiz, 1845
Meaning of generic name
From Greek, parexis, a furnishing, or decoration
Meaning of specific name
curved (around itself or backwards) [and falcatus means "with a sickle"]
Length: 15 cm
Articulated skeletons.
Age and Distribution
Lower Devonian, Tillywhandland, Scotland
Acanthodii Climatiiformes Climatiidae
Image by Nobu Tamura (click to enlarge)
Parexus recurvus, November 20, 2008:

Palaeoherpeton decorum

Originally named Palaeogyrinus ("Ancient tadpole"), Palaeoherpeton from the Upper Carboniferous of Scotland is an Embolomeri tetrapod related to Eogyrinus but smaller in size. It is only known by a single incomplete skull with no postcranial remains.

Palaeoherpeton decorum
(Watson, 1926) Panchen, 1970
Meaning of generic name
Ancient Crawler
Meaning of specific name
Fitting / Embellishing
Skull length: 17 cm; Length: 2 m
Age and Distribution
Parrot Coal of Pirnie Colliery Fifeshire, Scotland, UK
Tetrapoda Emblomeri Eogyrinidae
Further Reading
Panchen, A.L., 1964. The cranial anatomy of two Coal measure anthracosaurs. Phil. Trans. R. Soc. B 242, 207-281.
Palaeogyrinus decorus Watson, 1926

Pantydraco caducus

Pantydraco lived during the Late (Upper) Triassic (Rhaetian) Period and perhaps Early Jurassic of what is now the United Kingdom. Pantydraco was a genus of basal sauropodomorph dinosaur and was originally believed to be a juvenile Thecodontosaurus and described from a partial skeleton including a skull in 2003. However, further analysis led to the conclusion and discovery that Pantydraco warranted its own separate genus after a paper was published in 2007. Together with Thecodontosaurus antiquus, it is the basalmost sauropodomorph known from Europe.

The diet of Pantydraco would have most likely been herbivorous but there is debate whether Pantydraco would have been an omnivore, it would have walked bipedally. Only one valid species of Pantydraco is recognised; caducus. The name Pantydraco comes from Pantyffynnon a small village in Southern Wales where the specimen was discovered in a quarry.

Pantydraco caducus
(Yates, 2003)
Meaning of generic name
Abbreviation of Pant-y-ffynnon Quarry plus Latin, draco, a fabulous lizard-like animal.
Meaning of specific name
Latin, caducus, fallen (the holotype specimen may have died by falling into a fissure).
Holotype (BMNH P24): nearly complete skull, vertebrae, humeri, partial right ischium.

Referred specimens: several partial skeletons and isolated bones (BMNH P24/3, a right ischium; BMNH P39/2, a left coracoid; BMNH P59/5, a right quadrate; BMNH P64/1, a series of eight proximal–mid caudals; BMNH P65/21, a right ectopterygoid; BMNH P77/1, a series of distal caudal vertebrae, the right ilium, femur, tibia, fibula and pes; BMNH P126/1, a ?proximal pubis; BMNH P141/1, a basioccipital.)
Age and Distribution
Horizon: Upper Triassic (Rhaetian) or Lower Jurassic. Locality: old Pant-yffynnon Quarry , near Bonvilston, South Glamorgan, South Wales, UK.
Dinosauria Saurischia Sauropodomorpha
Further Reading
A. M. Yates. 2003. A new species of the primitive dinosaur Thecodontosaurus (Saurischia: Sauropodomorpha) and its implications for the systematics of early dinosaurs. Journal of Systematic Palaeontology 1(1):1-42.

P. M. Galton, A. M. Yates, and D. M. Kermack. 2007. Pantydraco n. gen. for Thecodontosaurus caducus Yates, 2003, a basal sauropodomorph dinosaur from the Upper Triassic or Lower Jurassic of South Wales, UK. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen 243(1):119-125.
Thecodontosaurus caducus Yates, 2003
Image by Nobu Tamura (click to enlarge)
Pantydraco caducus, October 22, 2007:
Creationist suspicion:
What if Pantydraco and Thecodontosaurus antiquus are both just varieties of some other kind?/HGL

Ischnacanthus gracilis

Ischnacanthus was a type of fish belonging to the class Acanthodii. Remains have been discovered in the Lochkovian/Emsian stages of the Devonian Period in the Tillywhandland quarry (one of the best early Devonian fish sites in Scotland), Old Red Sandstone, Forfarshire, they first appeared in the very late Silurian Period. Fossil remains have also been discovered in North America.

Their bodies were covered with small mosaic scales, they had small teeth which were primarily situated in the lower jaws, and some of the species had no teeth. The majority of their fins (except caudal) were supported by elongated spines made of dentine. Three species are attributed to Ischnacanthus; the more commonly known I.gracilis and, I.kingi and I.wickhami, the latter two named by White in 1961, they were most likely active predatory fish.

Ischnacanthus gracilis
Egerton, 1861
Meaning of generic name
Thin spine
Meaning of specific name
Length: 10 cm
Complete fossils.

[Complete skeletons or more ?]
Age and Distribution
Early Permian, Tillywhandland Quarry, Forfar, Scotland
Acanthodii Ischnacanthiformes Ischnacanthidae
Further Reading
C. J. Burrow. 2007. Early Devonia (Emsian) Acanthodian Faunas Of The Western USA. Journal of Paleontology; September 2007; v. 81; no. 5; p. 824-840.

Gnathosaurus subulatus

The first remains of Gnathosaurus (a jaw fragment) found in the Solnhofen limestones of Bavaria were mistaken with those of a crocodile. This small size pterosaur is characterized by a slender skull comparable to Ctenochasma but with a distinct sagittal crest on top of the snout. A series of vertebrae from the Purbeck Limestones in England, named Pterodactylus macrurus may belong to G. subulatus.

Gnathosaurus subulatus
Meyer, 1834
Meaning of generic name
Jaw Lizard.
Meaning of specific name
"with an awl/awls" or "awled" (referring to teeth)
Skull length: 28 cm, Wingspan: 1.7 m
Several skeletons.
Age and Distribution
Late Jurassic (Tithonian), Solnhofen limestones, Bavaria, Southern Germany.

Purbeck limestones, Wealden, Dorset, England, UK.
Pterosauria Pterodactyloidea Ctenochasmatoidea Ctenochasmatidae Gnatosaurinae
Further Reading
Seeley H. G., 1869, Note on the Pterodactylus macrurus (Seeley), a new species from the Purbeck Limestone, indicated by caudal vertebrae five inches long, (and) Note on the thinning away to the westward in the Isle of Purbeck of the Wealden and Lower Greensand strata. Proc. Cambridge philos. Soc. 7-10, 130.
Crocodilus multidens Munster, 1832; Gnathosaurus multidens (Munster, 1832); Gavialis priscus Quenstedt, 1855 (nomen dubium); Gnathosaurus macrurus (Seeley, 1869) Howse & Milner, 1995; Pterodactylus macrurus Seeley, 1869 (nomen dubium)

Eustreptospondylus oxoniensis

Eustreptospondylus is known from a single disarticulated skeleton of a juvenile or subadult from the marine deposits of the Middle Jurassic Oxford Clay of England. This medium size theropod is the best known megalosaurid from the northern hemisphere, and the second most complete theropod skeleton known from Western Europe (Baryonyx being first). The fact that it was discovered in marine sediments indicate that it may have been a coastal predator whose carcass was washed ashore. Although the estimated length of the juvenile skeleton is 4-5 meters, the adults were probably much larger.

Eustreptospondylus oxoniensis
Walker, 1964
Meaning of generic name
Well-curved vertebrae
Meaning of specific name
from Oxford [or from Oxford Clay Formation]
Length: 5 m
Disarticulated skull and postcranial elements.
Age and Distribution
Chipping Norton Formation, Oxford Clay Formation, Oxfordshire, Middle Oxford Clay Formation (Stewartby Member), Buckinghamshire, England.
Dinosauria Saurischia Theropoda Spinosauroidea Megalosauridae
Further Reading
A. D. Walker. 1964. Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs. Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences 248:53-134.
Magnosaurus oxoniensis (Walker, 1964) Rauhut, 2003
Image by Nobu Tamura (click to enlarge)
Eustreptospondylus oxoniensis, June 10, 2012:

Elginia mirabilis

Elginia was a small pareiasaur, and part of the family pareiasauridae. Fossils of Elginia have been discovered in rocks dating to the Wuchiapingian and Tatarian Stages of the late Permian Period. It was discovered at Cutties Hillock Millstone Quarry, near Elgin, Scotland hence the name Elginia, at least two adult specimens have been discovered at this locality.

Elginia was a dwarf form of pareiasaur, it probably only reached about 60 centimetres in length (2feet). Perhaps the most striking feature about this animal was the several protruding spikes from the skull two of which were exceedingly long; the spikes were probably used for display purposes as opposed to a defence mechanism. Ribs, presacral vertebrae, sections of the shoulder girdle and forelimbs have also been discovered from Elginia. Two species of Elginia are currently considered valid; mirabilis and gordoni. Elginia like all pareiasaurs was herbivorous and probably fed on land plants, it became extinct at the end of the Permian Period. Several tracks of footprints in Scotland have also been considered to belong to Elginia.

Elginia mirabilis
Newton, 1893
Meaning of generic name
From Elgin
Meaning of specific name
Length: ~60 cm
Skull, Ribs, Presacral Vertebrae, Shoulder Girdle and Forelimbs
Age and Distribution
Upper Permian Elgin Formation of Scotland, UK.
Anapsida Hallucicrania Pareiasauria
Further Reading
Newton, E. T., 1893, On some new reptiles from the Elgin Sandstone: Philosophical Transactions of the Royal Society of London, series B, v. 184, p. 473-489.

P. S. SPENCER and M. S. Y. LEE. A JUVENILE ELGINIA AND EARLY GROWTH IN PAREIASAURS. Journal of Paleontology; November 2000; v. 74; no. 6; p. 1191-1195; DOI: 10.1666/0022-3360 (2000 074<1191:AJEAEG>2.0.CO;2 © 2000 Paleontological Society)
Image by Nobu Tamura (click to enlarge)
Elginia mirabilis, November 8, 2007:

Tuesday, 17 December 2013

Dimorphodon macronyx

Probably one of the most well known pterosaurs after Pteranodon et al, Dimorphodon was a genus of medium-sized pterosaur known from England and described by Richard Owen in 1859. The name Dimorphodon means ‘two-form tooth’ in reference to the two distinct types of teeth in its jaws. Mary Anning one of the earliest and most noted fossil collectors discovered the first specimen of Dimorphodon in 1828 from the Blue Lias formation within the Hettangian/Sinemurian Stages of the Lower Jurassic rocks of Lyme Regis, Dorset, England.

The two types of teeth implied in the name are present in each jaw, a set of 30-40 small pointed teeth with four larger teeth at the front. The wingspan of Dimorphodon was around 1.2-2.5 metres (4-8 ft), it had a large bulky skull 22 centimetres in length and the tail consisted of thirty vertebrae, the latter vertebrae were stiffened by elongated vertebral processes. Much debate on how Dimorphodon may have stood/walked (when it wasn’t flying) has led to several ideas proposed, whether it was quadrupedal or bipedal. It probably inhabited coastlines hunting for fish in the oceans.

Dimorphodon macronyx
(Buckland, 1829)
Meaning of generic name
Two-formed tooth
Meaning of specific name
Big Claw
Wingspan: 1.2 m, Length: 1 m, Skull: 21.5 cm
Several specimens all disarticulated and crushed
Age and Distribution
Lyme Regis region, Dorset and Gloucestershire, England, UK
Pterosauria Dimorphodontidae
Further Reading
Owen, R. (1859). "On a new genus (Dimorphodon) of pterodactyle, with remarks on the geological distribution of flying reptiles." Rep. Br. Ass. Advmnt Sci., 28 (1858): 97–103.
Pterodactylus macronyx Buckland, 1829, Pterodactylus marderi Owen, 1874 [nomen dubium], Dimorphodon weintraubi Clark, Hopson, Hernández, Fastovsky & Montellano, 1998

Dakosaurus maximus

Dakosaurus (meaning "tearing lizard") is better known from the well publicized 1996 discovery of the Argentinian species, D. andiniensis, dubbed "Godzilla" in the press, but the first remains of this animal were actually found in Western Europe, including England, with the species D. maximus.

With an estimated length of up to 6 meters, Dakosaurus was the top predator of its time, feeding on large prey which might have included sharks, ichthyosaurs and plesiosaurs. It had a relatively short skull compared to the other thalattosuchians, with jaws equipped with huge teeth ideal for crushing bones. Dakosaurus lived during the Kimmeridgian and Tithonian and was represented by four species: D. maximus, D. andiniensis, D. manselii, and D. nicaeensis.

Dakosaurus maximus
von Quenstedt, 1856
Meaning of generic name
Tearing Lizard
Meaning of specific name
maximus = largest,

[andiniensis = from Andes, nicaeensis = from Nicea/Nice in Turkey or from Nice/Nizza in France, manselii = of Mansel ?]
Length: 6 m
Several isolated bones, teeth,
Age and Distribution
Kimmeridgian - Tithonian, Europe, South America
Paracrocodylomorpha, Diapsida, Archsauromorpha, Mesoeucrocodylia, Thalattosuchia, Metriorhynchidae
Further Reading
P. Vignaud (1) ; Z. Gasparini 1996, New Dakosaurus (Crocodylomorpha, Thalattosuchia) in the Upper Jurassic of Argentina, Comptes rendus de l'Académie des sciences.vol. 322, no3, pp. 245-250 (11 ref.)
Other species
D. andiniensis, Vignaud & Gasparini, 1996 D. manselii, Hulke, 1870 and D. nicaeensis, Ambayrac, 1913.
Dacosaurus Sauvage, 1873 Plesiosuchus Owen, 1884
Image by Nobu Tamura (click to enlarge)
Dakosaurus maximus, December 12, 2008

Coccosteus cuspidatus

Coccosteus is an extinct genus of arthrodire placoderm; placoderms were a class of armoured prehistoric fish. Their fossils have been discovered throughout Europe and across North America. Fossils of Coccosteus are very common in the Sandwick Fish Bed’s of Scotland. Only two known species are attributed to Coccosteus including; cuspidatus and decipiens. The head was covered with a regular number of bony plates and the body of these fish were long and slender ending in a narrow tail. This genus could grow to lengths of around 40 cm (almost 16 inches).

What Coccosteus lacked in size it made up for with its mouth. It had an internal joint between its neck vertebrae and the back of the skull, allowing the mouth to be opened even wider, this allowed Coccosteus to feed on fairly large prey. All arthrodires had bony dental plates in their jaws; these plates formed a sharp ‘beak’. The beak in arthrodires has often been falsely identified as ‘true teeth’, where in actual fact the beak is a result of the dental plates grinding against one another, thus keeping the beak sharp.

Coccosteus cuspidatus
Miller ex Agassiz, 1841
Meaning of generic name
Seed Bone-y

[Seed-Bone as a noun would have been kokkosteon in Greek.]
Meaning of specific name
Length: 25-40 cm
Complete specimens

[Complete with soft tissue or just complete with skeleta and outer bone parts ?]
Age and Distribution
Achanarras Horizon, Middle Old Red Sandstone, Sandwick Fish Bed's, Scotland, Middle Devonian, (Eifelian-Givetian).
Placodermi Arthrodira Coccosteoidea Coccosteidae
Further Reading
I.-Homosteus, Asmuss, compared with Coccosteus, Agassiz. Dr R. H. Traquair. Geological Magazine (Decade III), Volume 6, Issue 01, January 1889, pp 1-8 Published Online by Cambridge University Press 01 May 2009
Image by Nobu Tamura (click to enlarge)
Coccosteus cuspidatus, August 11, 2007:

Camelotia borealis

Camelotia was a large sauropodomorph (estimated length: 10 m) from the Upper Triassic of England. It is known from fragmentary postcranial elements. It is generally considered related to the South African Melanorosaurus.

Camelotia borealis
Galton, 1985
Meaning of generic name
From Camelot
Meaning of specific name
From the North
Length: ? 10 m , Skull length: ?
Holotype (BMNH R.2870-2874, R.2876-2878): Vertebrae, pubis, ischium, femur, tibia, phalanges
Age and Distribution
Horizon: Westbury Formation, Up. Triassic (Rhaetian).

Locality: Wedmore Hill, Somerset, England, UK.
Dinosauria Saurischia Sauropodomorpha Sauropoda Anchisauria Melanosauridae
Further Reading
P. M. Galton. 1985. "Notes on the Melanorosauridae, a family of large prosauropod dinosaurs (Saurischia: Sauropodomorpha)." Géobios 18(5):671-676.

P. M. Galton. 1998. "Saurischian dinosaurs from the Upper Triassic of England: Camelotia (Prosauropoda, Melanorosauridae) and Avalonianus (Theropoda, ?Carnosauria)." Palaeontographica Abteilung A 250(4-6):155-172
Gresslyosaurus ingens Huene, 1907-08, 1932 referred, Plateosaurus borealis (Galton, 1985) Galton, 2001; Avalonia sanfordi Seeley, 1898 (partim); Avalonianus sanfordi (Seeley, 1898) Kuhn, 1961; Picrodon herveyi Seeley, 1898 (partim)

Baryonyx walkeri

Baryonyx is known from a partial skull and postcranial skeleton and is to date the most complete theropod found in England, it was discovered in a pit in Surrey, England, 1983. It was found by amateur palaeontologist William Walker. At least 70% of the specimen was recovered and is on display in the Natural History Museum, London. Its hands were equipped with a huge claw and its crocodile-like snout indicate it was probably a piscivorous animal. It is possible that the genera Suchomimus and Cristatusaurus are junior synonyms of Baryonyx. Suchosaurus cultridens from the Early Cretaceous of England, known from teeth is most probably the same animal than Baryonyx walkeri.

Baryonyx walkeri
Charig & Milner, 1986
Meaning of generic name
Heavy Claw
Meaning of specific name
of Walker
Length: 9 m
Partial skull and associated postcranial skeleton.
Age and Distribution
Wealden Beds, Smokejacks Pit, Ockley, Surrey, England.
Dinosauria Saurischia Theropoda Spinosauroidea Spinosauridae
Further Reading
A. J. Charig and A. C. Milner. 1986. "Baryonyx, a remarkable new theropod dinosaur." Nature 324(6095):359-361.

Charig, A. J., and Milner A. C., 1990, The systematic position of Baryonyx walkeri, in the light of Gauthier’s reclassification of the Theropoda: In: Dinosaur Systematics, Approaches and Perspectives. Edited by Kenneth Carpenter and Philip J. Currie. Cambridge University Press, p. 127-140.
possible such see text above
Images by Nobu Tamura (click to enlarge)
Baryonyx walkeri, April 5, 2007
same, February 2, 2013:

Saturday, 14 December 2013

Asylosaurus yalensis

Asylosaurus yalensis
Galton, 2007
Meaning of generic name
"Unharmed or Sanctuary Lizard"
Meaning of specific name
Refers to Yale University where O. C. Marsh took the specimen so it was unharmed in air raids on BCM in November, 1940.
Body Length: ?
Holotype YPM 2195: A partial skeleton including ribs, gastralia, shoulder girdle, dorsal vertebrae and limb material
Age and Distribution
Horizon: Triassic Period (Rhaetian)

Locality: Durdham Down, Clifton, Bristol, U.K.
Dinosauria Saurischia Sauropodomorpha
Further Reading
Galton, Peter (2007). "Notes on the remains of archosaurian reptiles, mostly basal sauropodomorph dinosaurs, from the 1834 fissure fill (Rhaetian, Upper Triassic) at Clifton in Bristol, southwest England". Revue de Paléobiologie 26 (2): 505–591.
[If the specimen was already there in 1940, what was it known as back then? Was it subsumed under some other already named species back then, the fossil from Durdham Down in Yale?]

Anthracosaurus russelli

Anthracosaurus russelli was a large (estimated length of 3 meters) predatorial eel-like creature that lived in the swamps of Scotland during the Upper Carboniferous. The eel-like shape of the body is assumed on the basis of related genera but the details of the postcranial skeleton is a mystery as only skull fragments of this animal have been found mainly in the Coal Measures of Scotland. A. russelli is currently the only recognized species as A. lancifer from Linton, Ohio, also known from a skull, has been synonymized with Leptophractus obsoletus.

Anthracosaurus russelli
Huxley, 1863
Meaning of generic name
Coal Lizard
Meaning of specific name
of Russell
Skull length: 40 cm, Length: 3 m
Skulls and skull fragments.
Age and Distribution
Blackband Ironstone of Airdie, near Glasgow, Scotland (Westphalain B); Usworth Colliery, Washington, Tyne and Wear, England (Westphalian A), UK
Tetrapoda Emblomeri Anthracosauridae
Further Reading
Huxley, T. H., 1863, "Description of Anthracosaurus russelli, a new labyrinthodont form the Lanarkshire coal field": Quarterly Journal of the Geological Society of London, v. 19, p. 56-68.

Clack J.A. (1987) "Two new specimens of Anthracosaurus (Amphibia: Anthracosauria) from the Northumberland Coal Measures." Palaeontology, 30, 15-26.

Adelospondylus watsoni

Adelospondylus watsoni is only known from a small skull from the Lower carboniferous of Scotland (It was erroneously reported being from the Upper Carboniferous). It belongs to a very poorly known group of Lepospondyli amphibians called Adelospondyli consisting of four genera of very elongated aquatic animals with tiny limbs.

Adelospondylus watsoni
Carroll, 1967
Skull length: 5 cm, Length: 50 cm
Age and Distribution
Lower Carboniferous beds (?Serpukhovian) of Scotland.
Lepospondyli Adelospondyli Adelogyrinidae
Further Reading
Carroll, R. L., 1967, "An Adelogyrinid Lepospondyl Amphibian from the Upper Carboniferous": Canadian Journal of Zoology, v. 45, n. 1, p. 1-16.

Acanthodes bronii

Acanthodes is a genus of plankton feeding spiny sharks which was ubiquitous from the Early Carboniferous to the Early Permian. Fossils have been found throughough Europe and North Amrica. It had fewer spines than its other relatives such as Climatius. Many species of Acanthodes have been described: Acanthodes bourbonensis Heidtke, 1996 (Lower Permian of France); Acanthodes boyi Heidtke, 1993 (Lower Permian of Germany); Acanthodes bridgei Zidek, 1976 (Upper Carboniferous of Kansas); Acanthodes bronii Agassiz, 1833 (Lower Permian of Germany); Acanthodes fritschi Zajic, 1998 (Upper Carboniferous of Czech Republic); Acanthodes gracilis (Beyrich, 1848) (Lower Permian of Czech Republic, Poland and Germany); Acanthodes kinneyi Zidek, 1992 (Upper Carboniferous of New Mexico); Acanthodes lopatini Rohon, 1889 (Lower Carboniferous of southern Central Siberia, Russia); Acanthodes luedersensis (Dalquest et al., 1988) (Lower Permian of Texas); Acanthodes lundi Zidek, 1980 (Upper Carboniferous of Montana); Acanthodes nitidus Woodward, 1891 (Lower Carboniferous of Scotland); Acanthodes ovensi White, 1927 (Lower Carboniferous of Scotland); Acanthodes sippeli Heidtke, 1996 (Upper Carboniferous of Germany); Acanthodes stambergi Zajic, 2005 (Lower Permian of Czech Republic); Acantodes sulcatus Agassiz, 1835 (Lower Carboniferous of Scotland); Acanthodes tholeyi Heidtke, 1990 (Lower Permian of Germany); Acanthodes wardi Egerton, 1866 (Upper Carboniferous of England and Scotland).

Acanthodes bronii
Agassiz, 1833

[Note: he was opposed to Darwin, while a botanist supported the latter.]
Length: 30 cm
Complete fossils.
Age and Distribution
Early Permian, Rotliegend, Germany
Acanthodii Acanthodiformes Acanthodidae

United Kingdom

  • United Kingdom
    • Acanthodes (Acanthodi, Lo.-Up. Carb., Scotland, England)
    • Adelospondylus (Lepospond.,Lo. carb. [Serp.], Scotland)
    • Anthracosaurus (Embolomeri, Up. Carb. [Westph B, Moscov.], Scotland)
    • Asylosaurus (Sauropod Triassic, Bristol)
    • Baryonyx (Theropod, Wealden beds, Lo. Cret. [Barrem.], England)
    • Camelotia (Sauropod., Westbury Fm, Up. Trias. [Rhaetian], England)
    • Climatius (Acanthodi, Lo. Dev., Scotland)
    • Coccosteus (Placodermi, Mid Dev, [Eifelian-Givetian], Scotland)
    • Dakosaurus (Thalattosuchia, Upper Jurassic. [Kimm/Tithon] England)
    • Dimorphodon (Pterosaur, Lyme Regis, Lo. Jur. [Sinem.], England)
    • Elginia (Pareiasaur, Elgin Fm, Up. Perm. [Wuch.])
    • Eustreptospondylus (Theropod, Oxford Clay Fm, Mi. Jur. [Call.], England)
    • Gnathosaurus (Pterosaur, Wealden, Up. Jur. [Tith.], England)
    • Ischnacanthus (Acanthodii, Old Red Sandstone Fm, Lo Dev, Scotland)
    • Istiodactylus (Pterosaur, Vectis Fm, Lo. Cret. [Barr.] Isle of Wight)
    • Lonchodectes (Pterosauria, Lower - Upper Cretaceous, England)
    • Metriorhynchus (Thalattosuchia, Low to Upper Jurassic, England, Europe)
    • Ornithocheirus (Pterosauria, Upper Cretaceous [Ceno], England, Europe)
    • Palaeoherpeton
    • Pantydraco (Sauropod., Up. Trias. [Rhaet.] or Lo. Jur. [Hett.] South Wales)
    • Parexus
    • Pederpes
    • Pelagosaurus (Thalattosuchia, Lower Jurassic. [Toar] Somerset)
    • Pholiderpeton
    • Proterogyrinus
    • Steneosaurus (Thalattosuchia, Low Jurassic/Low Cret. England)
    • Thecodontosaurus (Sauropod., Bristol, Up. Trias. [Nor.-Rhaet.] England)
  • Scat Craigs Beds, Scotland, Upper Devonian (Upper Frasnian)
    • Cosmacanthus malcolmsoni (Placodermi Arthrodira Groenlendaspididae)
    • Bothriolepis paradoxa (Placodermi Antiarchi)
    • Psammosteus cf falcatus (Heterostraci Psammostiform Psammosteidae)
    • Traquairosteus pustulatus (Heterostraci Psammostiform Psammosteidae)
    • Holoptychius nobilissimus (Sarcopterygii Porolepiform)
    • Holoptychius giganteus (Sarcopterygii Porolepiform)
    • Holoptychius decoratus (Sarcopterygii Porolepiform)
    • Duffichthys mirabilis (Sarcopterygii Porolepiform)
    • Conchodus ostreiformis (Dipnoi Dipteridae)
    • Elginerpeton pancheni (Tetrapoda Elginerpetontidae)
  • Scotland, Lower Carboniferous (Visean-Namurian)
    • Chondrenchelys problematica (Chondrichthyes Chondrenchelyiform) Glencartholm
    • Crassigyrinus scoticus (Tetrapoda Crassigyrinidae) Gilmerton
    • Acherontiscus caledoniae (Lepospondyli Adelospondyli Acherontiscidae)
    • Adelogyrinus simnorhynchus (Lepospondyli Adelospondyli Adelogyrinidae) Dunnet Shale
    • Palaeomolgophis scoticus (Lepospondyli Adelospondyli Adelogyrinidae) Curley Shale
    • Lethiscus stocki (Lepospondyli Aistopoda Lethiscidae)
    • Ophiderpeton kirktonense (Lepospondyli Aistopoda Ophiderpetontidae) East Kikton
    • Silvanerpeton miripides (Embolomeri) East Kirkton
    • Eoherpeton watsoni (Embolomeri Eoherpetontidae) Gilmerton
    • Pholidogaster pisciformis (Colosteoidea Colosteidae) Gilmerton
    • Casineria kiddi (Amniota) Gullane Fm
  • Newsham, Northumberland, UK, Upper Carboniferous (Westphalian B, Lower Moscovian)
    • Pteroplax cornutus (Embolomeri Eogyrinidae)
    • Eogyrinus attheyi (Embolomeri Eogyrinidae)
    • Anthracosaurus russelli (Embolomeri Anthracosauria Anthracosauridae)
    • ?Ophiderpeton nanum (lepospondyli Aistopoda Ophiderpetontidae)
    • Batrachiderpeton reticulatum (Lepospondyli Nectridea Keraterpetontidae)
    • Megalocephalus pachycephalus (Temnospondyli Loxommatidae)
  • Kenilworth Sandstone Formation, England, Lower Permian (Asselian)
    • Haptodus grandis (Synapsida Eupelycosauria Sphenacodontia Haptodidae)
  • Lossiemouth Sanstones Formation, Scotland, Upper Triassic (Latest Carnian/Early Norian)
    • Leptopleuron lacertinum (Anapsida Procolophonomorpha Procolophonidae)
    • Brachyrhinodon taylori (Sphenodontia Sphenodontidae)
    • Hyperodapedon gordoni (Rhynchosauria Rhynchosauridae)
    • Ornithosuchus longidens (Ornithosuchia Ornithosuchidae)
    • Stagonolepis robersoni (Aetosauria Stagonolepidae)
    • Erpetosuchus granti (Paracrocodylomorpha Erpetosuchidae)
    • Saltopus elginensis (Archosauria)
    • Scleromochlus taylori (Archosauria Scleromochlidae)
  • England, Upper Triassic (Norian-Rhaetian)
    • Diphydontosaurus avonis (Sphenodontia Sphenodontidae)
    • Rileyasuchus bristolensis (Phytosauria) nomen dubium
    • Agnosphytis cromhallensis (Saurischia?)
    • Asylosaurus yalensis (Sauropodomorpha)
    • Thecodontosaurus antiquus (Sauropodomorpha)
  • Wales, Upper Triassic (Norian/Rhaetian)
    • Terrestrisuchus gracilis (Crocodylomorpha Sphenosuchis Sphenosuchidae)
  • SouthWest England, Upper Triassic (Rhaetian)
    • Pachystropheus rhaeticus (Choristodera)
  • Lias Formation, England, Lower Jurassic (Early Sinemurian)
    • Sarcosaurus woodi (Theropoda Coelophysoidea?)
  • Charmouth Mudstone Formation, Dorset, England, Lower Jurassic (Sinemurian)
    • Scelidosaurus harrisonii (Ornithischia Ankylosauria Scelidosauridae)
    • Ichthyosaurus (Ichthyopterygia IchthyosauriaThunnosauria)
  • Middle Inferior Oolite Formation, Inferior Oolite Group, England, Middle Jurassic (Lower Bajocian)
    • Magnosaurus nethercombensis (Theropoda Megalosauroidea Megalosauridae)
  • Oxford Clay Formation, South England, Middle-Upper Jurassic (Callovian-Lower Oxfordian)
    • Gryphaea dilatata (Mollusca Bivalvia Gryphaeidae) Weymouth member, Oxfordian
    • Loricatosaurus priscus (Ornithischia Stegosauria Stegosauridae Stegosaurinae)
    • Lexovisaurus durobrivensis (Ornithischia Stegosauria Stegosauridae Stegosaurinae)
    • Callovosaurus leedsi (Ornithopoda Iguanodontia Dryosauridae)
    • Cetiosauriscus stewarti (Sauropoda Diplodocoidea Diplodocidae)
    • Metriacanthosaurus parkeri (Theropoda Carnosauria Sinraptoridae) Weymouth member, Oxfordian
  • Taynton Limestone Formation, England, Middle Jurassic (Middle Bathonian)
    • Megalosaurus bucklandii (Theropoda Megalosauroidea Megalosauridae)
    • Iliosuchus incognitus (Theropoda Coelurosauria Tyrannosauroidea?)
  • Kilmaluag Formation, Skye, Scotland, Middle Jurassic (Late Bathonian)
    • Marmorerpeton kermacki (Lissamphibia)
  • Kirlington, Oxfordshire, England, Middle Jurassic (Late Bathonian)
    • Anoualerpeton priscus (Lissamphibia Allocaudata Albanerpetontidae)
    • Marmorerpeton kermacki (Lissamphibia Caudata)
    • Marmorerpeton freemani (Lissamphibia Caudata)
    • Eodiscoglossus oxoniensis (Lissamphibia Salientia Discoglossoidea)
    • Ctenogenys sp. (Choristodera)
  • Chipping Norton Limestone Formation, Great Oolite Group, England, Middle Jurassic (Lower Bathonian)
    • Cruxicheiros newmanorum (Theropoda Tetanurae?)
  • Forest Marble Formation, Great Oolite Group, Wiltshire, England, Middle Jurassic (Bathonian)
    • Cardiodon rugulosus (Sauropoda)
    • Cetiosaurus oxoniensis (Sauropoda Cetiosauridae)
    • Bothriospondylus robustus (Sauropoda Macronaria Brachiosauridae?) nomen dubium
  • White Limestone Formation, Great Oolite Group, Gloucestershire, England, Middle Jurassic (Middle to Late Bathonian)
    • Proceratosaurus bradleyi (Theropoda Tyrannosauroidea)
  • Kimmeridge Clay Formation, South England, Upper Jurassic (Kimmeridgian-Tithonian)
    • Dacentrurus armatus (Ornithischia Stegosauria Stegosauridae Dacentrurinae)
    • Camptosaurus prestwichii (Ornithopoda Iguanodontia Camptosauridae)
    • Bothriospondylus suffosus (Sauropoda Macronaria Brachiosauridae?) nomen dubium
    • Nannopterygius enthekiodon (Ichthyopterygia Ichthyosauria Thunnosauria Ophthalmosauridae)
    • Brachypterygius extremus, B. mordax (Ichthyopterygia Ichthyosauria Thunnosauria)
    • Stokesosaurus langhami (Theropoda Tyrannosauroidea)
  • Lulworth Formation, England, UK, Lower Cretaceous (Berriasian)
    • Nuthetes destructor (Theropoda Deinonychosauria Dromaeosauridae)
  • Hasting Beds, Sussex, Lower Cretaceous (Berriasian-Valanginian)
    • Regnosaurus northamptoni (Ornithischia Stegosauria)
  • Ashdown Formation, Hastings Group, Sussex, England, Lower Cretaceous (Early Valanginian)
    • Xenoposeidon proneneukos (Sauropoda Neosauropoda)
  • Speeton Clay Formation, Germany & England, Lower Cretaceous (basal Hauterivian)
    • Acamptonectes densus (Ichthyopterygia Ichthyosauria Opthalmosauridae Opthalmosaurinae)
  • Tunbridge Wells Sand Formation, Hastings Group, England, Lower Cretaceous (Upper Valanginian - Lower Hauterivian)
    • Valdoraptor oweni (Theropoda Tetanurae)
  • Wealden Group, England, UK, Lower Cretaceous (Hauterivian.-Aptian)
    • Pelorosaurus conybeari (Sauropoda Macronaria Brachiosauridae?)
    • Iuticosaurus valdensis (Sauropoda Macronaria Titanosauria)
    • Becklespinax altispinus (Theropoda Carnosauria Allosauroidea)
  • Wessex Formation, Wealden Group, Isle of Wight, UK, Lower Cretaceous (Upper Hauterivian- Lower Barremian)
    • Polyacrodus parvidens (Elasmobranchii Polyacrodontidae)
    • Lissodus striatus (Elasmobranchii Lonchidiidae)
    • Lissodus breve (Elasmobranchii Lonchidiidae)
    • Caulkicephalus trimicrodon (Pterosauria Pterodactyloidea Ornithocheirididae)
    • Hypsilophodon foxii (Ornithopoda Hypsilophodontidae)
    • Iguanodon bernissartensis (Ornithopoda Iguanodontia Iguanodontidae)
    • Mantellisaurus atherfieldensis (Ornithopoda Iguanodontia)
    • Valdosaurus canaliculatus (Ornithopoda Iguanodontia Dryosauridae)
    • Mantellisaurus atherfieldensis (Ornithopoda Iguanodontia Iguanodontoidea)
    • Oplosaurus armatus (Sauropoda Turiasauria?)
    • Eucamerotus foxi (Sauropoda Macronaria Brachiosauridae?) nomen dubium
    • Yaverlandia bitholus (Theropoda Tetanurae)
    • Neovenator salerii (Theropoda Carnosauria Neovenatoridae)
    • Calamosaurus foxi (Theropoda Coelurosauria?)
    • Aristosuchus pusillus (Theropoda Compsognathidae)
    • Thecocoelurus daviesi (Theropoda Therizinosauroidea?)
    • Eotyrannus lengi (Theropoda Tyrannosauroidea)
  • Vectis Formation, Wealden Group, Isle of Wight, UK, Lower Cretaceous (Barremian-Aptian)
    • Mantellisaurus atherfieldensis (Ornithopoda Iguanodontia Iguanodontoidea)
  • Cambridge Greensand Formation, Lower-Upper Cretaceous (Albian-Cenomanian)
    • Ornithocheirus simus (Pterosauria Pterodactyloidea Ornithocheirididae)
    • Ornithocheirus denticulatus (Pterosauria Pterodactyloidea Ornithocheirididae)
    • Anhanguera fittoni (Pterosauria Pterodactyloidea Ornithocheirididae)
    • Coloborhynchus sedgwicki (Pterosauria Pterodactyloidea Ornithocheirididae)
    • Lonchodectes machaeorhynchus (Pterosauria Pterodactyloidea Lonchodectidae)
    • Lonchodectes microdon (Pterosauria Pterodactyloidea Lonchodectidae)
    • Anoplosaurus curtonotus (Ornithischia Ankylosauria Nodosauridae)
    • Brachypterygius cantabridgiensis (Ichthyopterygia Ichthyosauria Thunnosauria)