First evidence of ganoin- scaled Halecomorphi (Neopterygii) in the Lower Jurassic of Holzmaden and Ohmden, Germany

authored by

Martin Ebert, Detlev Thies, Rolf B. Hauff

Abstract

The Posidonienschiefer Formation (lower Toarcian) of the Holzmaden region, Baden­ Württemberg, in southwestern Germany is world-famous for its marine fossils, including excellently preserved fossil vertebrates, especially ichthyosaurs and plesiosaurs, but also fossil fishes. The study of the diversity and palaeoecology of fish within these deposits gives us further hints to understand the corresponding ecosystem. With Holzmadenfuro rebmanni new gen. et sp. and Ohmdenfuro bodmani new gen. et sp., both curated at the Urweltmuseum Hauff in Holzmaden, we now describe the first ganoin­scaled Halecomorphi from the Posidonienschiefer of Germany. These new taxa are characterized by a specific combination of features, including body shape; number of parietals, extrascapulars, infraorbitals, dorsal and caudal fin rays, and vertical scale rows; number and shape of maxillary teeth; number and arrangement of supraorbitals; ornamentation of skull bones; insertion of dorsal, pelvic, and anal fins; position of lateral line in caudal fin area; shape and distribution of scales; and number and shape of serrations on scales. The more basal Halecomorphi with ganoid scales (Parasemionotiformes, Panxianichthyformes, and Ophiopsiformes) remain poorly known, compared with the more advanced halecomorph group of the Amiiformes (especially the Amiidae). Closer investigation of their taxonomic relationships is therefore important for understanding broader patterns of halecomorph evolution, especially the origin of the Jurassic Ophiopsiformes.

Organisation(s)

Institute of Geology

External Organisation(s)

Urwelt-Museum Hauff GmbH & Co. KG

Type

Article

Journal

Neues Jahrbuch fur Geologie und Palaontologie - Abhandlungen

Volume

295

Pages

307-326

No. of pages

20

ISSN

0077-7749

Publication date

31.03.2020

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Palaeontology

Sustainable Development Goals

SDG 14 - Life Below Water

Electronic version(s)

https://doi.org/10.1127/njgpa/2020/0889 (Access: Closed)