Protospinax

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Protospinax
Protospinax annectens in the Paleontological Museum in Munich

Protospinax annectens in the Paleontological Museum in Munich

Temporal occurrence
Bathonian (Middle Jurassic) to Kimmeridgian (Upper Jurassic)
Locations
  • Europe (Germany ( Solnhofen ), Luxembourg, England)
Systematics
Subclass : Plate gill (Elasmobranchii)
without rank: Sharks (selachii)
Superordinate : Squalomorphii
Order : Protospinaciformes
Family : Protospinacidae
Genre : Protospinax
Scientific name of the  family
Protospinacidae
Woodward , 1919
Scientific name of the  genus
Protospinax
Woodward, 1919

Protospinax is an extinct species of shark that was foundin the European flat seasin the Upper Jurassic . Fossils of the genus have been found in Germany, Luxembourg and England.

features

Representatives of protospinax were medium-sized sharks and about 1.5 meters were long. Her body was flattened, her head rounded. The pectoral and pelvic fins were very large. The coracoid bones had grown together on the abdomen. Of the two dorsal fins, each supported by a short spine, the first lay directly behind the pelvic fins, the second on the tail fin stalk. One anal fin was missing. The caudal fin was small and pointed. The gill slits were at the bottom of the head. The mouth was covered with wide flat teeth, which indicate a diet with hard-shelled invertebrates (durophagia). The centers of the vertebral bodies were ossified.

Systematics

Protospinax is placed in the shark superiority of the Squalea and applies to the supporters of the thesis that rays (Batoidea) are modified squaliform sharks, as a sister genus of the recent Hypnosqualea ( angel sharks (Squantiniformes), sawshark-like (Pristiophoriformes), rays). For scientists who prefer a basic dichotomy between sharks and rays, Protospinax is only sister genus of a common clade of angel and saw sharks.

literature

  • KA Frickhinger: Fossils Atlas Fishes. Mergus-Verlag, Melle 1991, ISBN 3-88244-018-X .
  • Joseph S. Nelson : Fishes of the World. John Wiley & Sons, 2006, ISBN 0-471-25031-7 .
  • Marcelo R. de Carvalho, John G. Maisey: Phylogenetic relationships of the Late Jurassic shark Protospinax Woodward 1919 (Chondrichthyes: Elasmobranchii). In: G. Arratia, G. Viohl: Mesozoic Fishes - Systematics and Paleoecology. Friedrich Pfeil, Munich 1996, ISBN 3-923871-90-2 , pp. 9-46 ( PDF file ).

Web links