Stenopterygius

Stenopterygius with cub.

• Europe

Stenopterygius is a genus of ichthyosaur from the Early to Middle Jurassic ( Toarcian - Aalenian ). Fossils of the genus have been found in England, France, Germany, Switzerland and Luxembourg. Stenopterygius is the most common Ichthyosauriergattung of Holzmaden Posidonia.

Where hundreds fully articulated skeleton were found, which often show the outer contours of the body. Only through these finds has been detected that the ichthyosaurs had a haiähnliche dorsal fin and a crescent-shaped caudal fin. Some of the fossil embryos in the body or just born kittens are obtained.

Features

Stenopterygius is difficult to diagnose by derived features and the genus may be paraphyletic. He was about three to four feet long. The pectoral and ventral fins were of medium length. The pectoral fins had four main and a shorter fifth finger, the pelvic fins three fingers and a reduced fourth. Older specimens were partially edentulous. Behind the orbit of the skull is very short, the temporal window is large, the maxilla ( upper jaw bone ), the palatine bone and the Quadratojugale (another skull bones) were short. Before the sacrum Stenopterygius had 44 to 46 vertebrae.

System

Stenopterygius belongs to the group of Thunnosauria, a group of advanced ichthyosaurs, which had a spindle-shaped body stiffened and fast- moving analogous to the tuna with caudal fin strokes through the water.

Species

• Stenopterygius quadriscissus ( Quenstedt, 1856) Jaekel, 1904 ( type species )
• Stenopterygius longifrons ( Owen, 1881)