Neurocranial anatomy of an enigmatic Early Devonian fish sheds light on early osteichthyan evolution
Loading...
Date
2018-05-29
Authors
Clement, Alice M
King, Benedict
Giles, Sam
Choo, Brian
Ahlberg, Per E
Young, Gavin C
Long, John A
Journal Title
Journal ISSN
Volume Title
Publisher
eLife Sciences Publications
Rights
Copyright Clement et al. This
article is distributed under the
terms of the Creative Commons
Attribution License, which
permits unrestricted use and
redistribution provided that the
original author and source are
credited.
Rights Holder
(CC) Copyright Clement et al.
Abstract
The skull of ‘Ligulalepis’ from the Early Devonian of Australia (AM-F101607) has significantly expanded our knowledge of early osteichthyan anatomy, but its phylogenetic position has remained uncertain. We herein describe a second skull of ‘Ligulalepis’ and present micro-CT data on both specimens to reveal novel anatomical features, including cranial endocasts. Several features previously considered to link ‘Ligulalepis’ with actinopterygians are now considered generalized osteichthyan characters or of uncertain polarity. The presence of a lateral cranial canal is shown to be variable in its development between specimens. Other notable new features include the presence of a pineal foramen, the some detail of skull roof sutures, the shape of the nasal capsules, a placoderm-like hypophysial vein, and a chondrichthyan-like labyrinth system. New phylogenetic analyses place ‘Ligulalepis’ as a stem osteichthyan, specifically as the sister taxon to ‘psarolepids’ plus crown osteichthyans. The precise position of ‘psarolepids’ differs between parsimony and Bayesian analyses.
Description
This
article is distributed under the
terms of the Creative Commons
Attribution License, which
permits unrestricted use and
redistribution provided that the
original author and source are
credited.
Keywords
Citation
Clement, A. M., King, B., Giles, S., Choo, B., Ahlberg, P. E., Young, G. C. & Long, J. A., 2018. Neurocranial anatomy of an enigmatic Early Devonian fish sheds light on early osteichthyan evolution. eLife, 7:e34349.