title: The cranial endocast ofDipnorhynchus sussmilchi(Sarcopterygii: Dipnoi) and the interrelationships of stem-group lungfishes.
abstract: The first virtual cranial endocast of a lungfish from the Early Devonian,Dipnorhynchus sussmilchi, is described.Dipnorhynchus,only the fourth Devonian lungfish for which a near complete cranial endocast is known, is a key taxon for clarifying primitive character states within the group. A ventrally-expanded telencephalic cavity is present in the endocast ofDipnorhynchusdemonstrating that this is the primitive state for "true" Dipnoi.Dipnorhynchusalso possesses a utricular recess differentiated from the sacculolagenar pouch like that seen in stratigraphically younger lungfish (Dipterus, Chirodipterus, Rhinodipterus), but absent from the dipnomorphYoungolepis. We do not find separate pineal and para-pineal canals in contrast to a reconstruction from previous authors. We conduct the first phylogenetic analysis of Dipnoi based purely on endocast characters, which supports a basal placement ofDipnorhynchuswithin the dipnoan stem group, in agreement with recent analyses. Our analysis demonstrates the value of endocast characters for inferring phylogenetic relationships.
authors: School of Biological Sciences, Flinders University, Adelaide, South Australia, Australia; Department of Sciences, Museum Victoria, Melbourne, Victoria, Australia; Department of Organismal Biology, Uppsala Universitet, Uppsala, Sweden.
authors: Alice M
authors: AM
authors: Clement
authors: School of Geosciences, University of Edinburgh , Edinburgh , United Kingdom.
authors: Tom J
authors: TJ
authors: Challands
authors: School of Biological Sciences, Flinders University , Adelaide , South Australia , Australia.
authors: John A
authors: JA
authors: Long
authors: Department of Organismal Biology, Uppsala Universitet , Uppsala , Sweden.
authors: Per E
authors: PE
authors: Ahlberg
keywords: Braincase; Cladistic analysis; Devonian; Dipnoi; Dipnorhynchus; Endocast; Microtomography; Palaeoneurology; Phylogeny