Naturwissenschaften

, Volume 95, Issue 5, pp 443–448

A new basal galeomorph shark (Synechodontiformes, Neoselachii) from the Early Jurassic of Europe

Short Communication

DOI: 10.1007/s00114-007-0341-0

Cite this article as:
Klug, S. & Kriwet, J. Naturwissenschaften (2008) 95: 443. doi:10.1007/s00114-007-0341-0

Abstract

Palaeospinacids are a group of basal galeomorph sharks and are placed in the order Synechodontiformes (Chondrichthyes, Neoselachii) ranging from the Permian to the Eocene. Currently, there is a controversy concerning the identity of diagnostic characters for distinguishing palaeospinacid genera because of very similar dental morphologies and the scarcity of articulated skeletal material. The most notable character for distinguishing species within the Palaeospinacidae is, however, the dental morphology. The main dental character uniting all palaeospinacids is the very specialised pseudopolyaulacorhize root vascularisation. A re-examination of articulated neoselachian skeletons from the Lower Jurassic of Lyme Regis (England) and Holzmaden (S Germany), and recently discovered specimens from the Upper Jurassic of the Solnhofen area and Nusplingen (S Germany) has yielded several hitherto unrecognised complete skeletons of the palaeospinacids Synechodus and Paraorthacodus enabling a re-evaluation of characters. These specimens indicate that the number of dorsal fins and the presence or absence of dorsal fin spines represent important features for identifying palaeospinacids. Synechodus bears two dorsal fins without fin spines, whereas Paraorthacodus only has a single dorsal fin lacking a fin spine directly in front of the caudal fin. All palaeospinacids from the Early Jurassic have two spines supporting the dorsal fins and are consequently assigned to a new genus, Palidiplospinax nov. gen. Three species are placed into the new taxon: Synechodus enniskilleni, S. occultidens and S. smithwoodwardi.

Keywords

Chondrichthyes Palaeospinacidae Palidiplospinax nov. gen. 

Abbreviations

BSPG

Bayerische Staatssammlung für Paläontologie und Geologie

GPIT

Geologisch-Paläontologisches Institut Tübingen

JME

Jura Museum Eichstätt

NHML

Natural History Museum London

SMNS

Staatliches Museum für Naturkunde Stuttgart

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Museum für NaturkundeHumboldt-Universität zu BerlinBerlinGermany

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