Egg capsule morphology provides new information about the interrelationships of chondrichthyan fishes

Author(s): Jan Fischer, Martin Licht, Jürgen Kriwet, Jörg W. Schneider, Michael Buchwitz, Peter Bartsch
Abstract: Chondrichthyan egg capsules have been well known since the nineteenth century, although their systematic affinities have been controversial for much of this time. Currently, 10 chondrichthyan egg capsule morphotypes are distinguished but their phylogenetic signal and evolutionary traits have not yet been analysed. Here, we present an analysis of all extant and currently known fossil chondrichthyan egg capsule types, and use a purported placoderm egg capsule as an outgroup for character coding. The phylogenetic hypothesis based on discrete morphological characters indicates that the enigmatic Carboniferous egg capsule morphotypes Crookallia and Vetacapsula form a monophyletic group together with the egg capsule morphotype of chimaerid holocephalans. The elasmobranch egg capsule morphotypes are sister to the holocephalan types. Based on these results we conclude that the ancestral chondrichthyan egg capsule morphotype combined features of those found in callorhinchid holocephalans and placoderms. From this ancestral type, two lineages of chondrichthyan egg capsule morphotypes diverged leading towards the major modern egg capsule morphotypes.
Organisation(s): Department of Palaeontology
External organisation(s): Museum für Naturkunde Magdeburg, Technische Universität Bergakademie Freiberg, Museum für Naturkunde Berlin - Leibniz-Institut für Evolutions- und Biodiversitätsforschung
Journal: Journal of Systematic Palaeontology, Taylor & Francis
Volume: 12
Pages: 389-399
No. of pages: 11
DOI: https://doi.org/10.1080/14772019.2012.762061
Publication date: 06-2013
Peer reviewed: Yes
Austrian Fields of Science 2012: 105118 Palaeontology
Keywords
ASJC Scopus subject areas: Palaeontology
Portal url: https://ucrisportal.univie.ac.at/en/publications/e82fe043-63d2-4ee9-8d24-6dc970e69fe4

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