Protospinax

Protospinax annectens in Munich Palaeontological Museum

• Europe ( Germany ( Solnhofen ), Luxembourg, England)

Protospinax is an extinct Haigattung that occurred in the Upper Jurassic in the European flat seas. Fossils of the genus have been found in Germany, Luxembourg and England.

Features

Representatives of Protospinax were medium-sized sharks and were about 1.5 meters long. Her body was flattened, rounded head. The pectoral and ventral fins were very large. The Coracoidknochen were grown together on the abdomen side. Of the two dorsal fins, which were each supported by a short spike, was the first directly behind the pelvic fins, the second on the tail fin shaft. An anal fin was missing. The caudal fin was small and pointed. The gill slits were located at the bottom of the sides of the head. The mouth was filled with broad flat teeth indicate a diet with hard-shelled invertebrates ( Durophagie ). The centers of the vertebrae were ossified.

System

Protospinax is placed in the Haiüberordnung the Squalea and is considered by the supporters of the theory that skate ( Batoidea ) are modified squaliforme sharks, as a sister genus of extant Hypnosqualea ( angel sharks ( Squantiniformes ) Sägehaiartige ( Pristiophoriformes ), skates and rays). For scientists who prefer a basal dichotomy between sharks and rays, Protospinax is only sister genus of a common clade of angels and Sägehaien.