[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Bathygnathus is Dimetrodon

Ben Creisler

A new paper:

Kirstin S. Brink, Hillary C. Maddin, David C. Evans & Robert R. Reisz (2015)
Re-evaluation of the historic Canadian fossil Bathygnathus borealis
from the Early Permian of Prince Edward Island.
Canadian Journal of Earth Sciences (advance online publication)
doi: 10.1139/cjes-2015-0100

The holotype and only known specimen of Bathygnathus borealis is a
partial snout with maxillary dentition of a presumed sphenacodontid
from the Lower Permian (Artinskian 283–290 Ma) redbeds of Prince
Edward Island, Canada. Due to its incomplete nature, assessment of the
taxon’s systematic position within a cladistic analysis had never been
performed. However, recent recognition of the phylogenetic utility of
tooth characters in sphenacodontids now allows for a modern
phylogenetic evaluation of B. borealis. Results show that B. borealis
is the sister taxon of Dimetrodon grandis, which is supported by
dental characters: crowns with mesial and distal denticles and roots
elongate, lacking plicidentine. An autapomorphy of B. borealis is the
large facial exposure of the septomaxilla. As Bathygnathus has
priority over Dimetrodon in the scientific literature, we suggest a
reversal of precedence is required to preserve the familiar name
Dimetrodon and to maintain universality, thus recognizing the new
species Dimetrodon borealis.


News release: