|Mystriosuchus steinbergeri |
Butler, Jones, Buffetaut, Mandl, Scheyer & Schultz, 2019
Phytosaurs are a group of carnivorous, semi-aquatic archosaurian reptiles that attained an almost global distribution during the Late Triassic. We here describe a new species of the phytosaur genus Mystriosuchus from the Norian Dachstein Limestone of Austria, from a marine lagoonal depositional environment. The new Austrian material comprises remains of at least four individuals of similar size (c. 4 m in total length) found in association but disarticulated, and includes one complete and two partial skulls and postcrania. All of these specimens apparently represent a single taxon, which is distinguished by numerous anatomical features from the two previously named Mystriosuchus species. Maximum parsimony analysis of a comprehensive morphological dataset provides strong statistical support for the phylogenetic position of the new Austrian taxon in Mystriosuchus, as the sister taxon to a clade comprising M. planirostris and M. westphali. Histological analysis suggests that the Austrian phytosaur specimens represent individuals that were at least eight years old at time of death, but which had not yet reached skeletal maturity. Taphonomic and palaeoenvironmental data suggest that these phytosaurs were living in the marine lagoon in which they were preserved, providing the strongest evidence to date of marine adaptations in phytosaurs.
Keywords: bone histology, fossils, marine adaptations, morphology, phylogeny, reptiles
|Figure 5. Holotype skull of Mystriosuchus steinbergeri sp. nov. (NHMW 1986/0024/0001)|
in right lateral (A), posterior (B), medial cross-sectional (C), dorsal (D) and ventral (E) views.
|Life reconstruction of Mystriosuchus steinbergeri sp. nov. in the Dachstein Limestone depositional environment.|
Illustration: Mark Witton.
Archosauriformes Gauthier, 1986
Phytosauria Jaeger, 1828
Parasuchidae Lydekker, 1885 sensu Kammerer et al., 2015
Mystriosuchinae Huene, 1915 sensu Kammerer et al., 2015
Leptosuchomorpha Stocker, 2010 sensu Jones & Butler, 2018
Mystriosuchini Huene, 1915 sensu Jones & Butler, 2018
Mystriosuchus Fraas, 1896
Mystriosuchus steinbergeri sp. nov.
Etymology: The species is named for Sepp Steinberger, who discovered and helped collect the holotype and referred specimens.
Richard J. Butler, Andrew S. Jones, Eric Buffetaut, Gerhard W. Mandl, Torsten M. Scheyer and Ortwin Schultz. 2019. Description and Phylogenetic Placement of A New Marine Species of Phytosaur (Archosauriformes: Phytosauria) from the Late Triassic of Austria. Zoological Journal of the Linnean Society. zlz014. DOI: 10.1093/zoolinnean/zlz014