Thursday, 26 December 2013

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:

No comments:

Post a Comment