Data from: The relationships of the Euparkeriidae and the rise of Archosauria

For the first time, a phylogenetic analysis including all putative
euparkeriid taxa is conducted, using a large data matrix analysed with
maximum parsimony and Bayesian analysis. Using parsimony, the putative
euparkeriid Dorosuchus neoetus from Russia is the sister taxon to
Archosauria + Phytosauria. Euparkeria capensis is placed one node further
from the crown, and forms a euparkeriid clade with the Chinese taxa
Halazhaisuchus qiaoensis and ‘Turfanosuchus shageduensis’ and the Polish
taxon Osmolskina czatkowicensis. Using Bayesian methods, Osmolskina and
Halazhaisuchus are sister taxa within Euparkeriidae, in turn sister to
‘Turfanosuchus shageduensis’ and then Euparkeria capensis. Dorosuchus is
placed in a polytomy with Euparkeriidae and Archosauria + Phytosauria.
Although conclusions remain tentative owing to low node support and
incompleteness, a broad phylogenetic position close to the base of
Archosauria is confirmed for all putative euparkeriids, and the ancestor
of Archosauria +Phytosauria is optimized as similar to euparkeriids in its
morphology. Ecomorphological characters and traits are optimized onto the
maximum parsimony strict consensus phylogeny presented using squared
change parsimony. This optimization indicates that the ancestral archosaur
was probably similar in many respects to euparkeriids, being relatively
small, terrestrial, carnivorous and showing relatively cursorial limb
morphology; this Bauplan may have underlain the exceptional radiaton and
success of crown Archosauria.