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.

Name

Parexus recurvus

Authority

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"]

Size

Length: 15 cm

Remains

Articulated skeletons.

Age and Distribution

Lower Devonian, Tillywhandland, Scotland

Classification

Acanthodii Climatiiformes Climatiidae

Image by Nobu Tamura (click to enlarge)

Parexus recurvus, November 20, 2008: