Ptycholepididae

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Ptycholepididae
Fossil of Ptycholepis bollensis from the Lower Jurassic of Württemberg, exhibited in the Museum für Naturkunde (Berlin)

Fossil of Ptycholepis bollensis from the Lower Jurassic of Württemberg , exhibited in the Museum für Naturkunde (Berlin)

Temporal occurrence
Triassic to Lower Jurassic
? up to 155.7 million years
Locations
Systematics
Trunk : Chordates (chordata)
Sub-stem : Vertebrates (vertebrata)
Superclass : Jaw mouths (Gnathostomata)
Class : Ray fins (Actinopterygii)
Order : Ptycholepidiformes
Family : Ptycholepididae
Scientific name of the  order
Ptycholepidiformes
Lehmann , 1958
Scientific name of the  family
Ptycholepididae
Brough , 1939

The Ptycholepididae are an extinct bony fish family that occurred from the Triassic to the Lower Jurassic in Europe and North America.

features

They are elongated, spindle-shaped fish whose scales are covered by a cosmin layer, while the cover bones of the skull have ganoin ridges . The lower jaw is elongated and is reminiscent of that of the Palaeoniscidae . The hyomandibular, a bone of the gill apparatus, is narrow. The gill cover does not contain an interopercular.

Systematics

The Ptycholepididae were originally assigned to the cartilage organoids (Chondrostei) or the bone organoids Holostei . Today they are considered to be the basal group of the ray fins (Actinopterygii). So far, two genres have been described, which some authors also combine.

literature

  • Arno Hermann Müller: Textbook of paleozoology. Volume 3: Vertebrates. Part 1: fish in the broader sense and amphibians. Gustav Fischer, Jena 1985.
  • Joseph S. Nelson , Terry C. Grande, Mark VH Wilson: Fishes of the World. John Wiley & Sons, 2016, ISBN 978-1118342336 , 115.

Web links