Lacerda et al. 2018
bring us a new large archosauriform, Pagosvenator (Figs. 1, 2), originally considered a member of the Erpetosuchidade (we’ll look more deeply at this clade in the next few days).
I could not find LRT sisters to Erpetosuchus (Litargosuchus and Terrestrisuchus) in the Lacerda et al. paper. Decuriasuchus was mentioned, but I don’t see it in the cladogram (Fig. 4). So, perhaps taxon exclusion on both ends is part of the Lacerda et al. problem.
Lacerda et al. acknowledge
the low support given to the nesting of several archosauriform taxa, but do not realize that taxon exclusion is a likely issue, resolved online for the last seven years by the LRT. Folks, you don’t have to use it, but it’s a good idea to include the sister taxa the LRT recovers, just to cover your bases. That’s what it is here for…a second opinion/analysis.
Lacerda et al. considered their find to be
the first occurrence of a member of the Erpetosuchidae in South America.
By contrast, the LRT
nests Pagosvenator with another large, Middle Triassic archosauriform from southern Brazil, Decuriasuchus (Fig. 3). So, the LRT sisters were coeval competitors of similar size and sharing a long list of traits.
The cladograms used by Lacerda et al. are inadequate due to taxon exclusion. Too few generic taxa. Too many suprageneric taxa.
Dyoplax was once considered an erpetosuchid.
Earlier the LRT (Fig. 1) nested Dyoplax with the swimming crocodile, Teleosaurus. Wikipedia reports, “Maisch, Matzke and Rathgeber (2013) questioned the placement of Dyoplax within Crocodylomorpha, and claimed that it shared important cranial and postcranial features with Erpetosuchus; the authors tentatively reassigned Dyoplax to Erpetosuchidae.” Seems no one wants to include Erpetosuchidae within the Crocodylomorpha. More taxa clarify this problem.
that the basal rauisuchian, Vjushkovia (Fig. 7), is the outgroup for Decuriasuchus and the Poposaurs + Archosaurs.
will be presented over the next few days.
França MAG, Ferigolo J and Langer MC 2011. Associated skeletons of a new middle Triassic “Rauisuchia” from Brazil. Naturwissenschaften.
Lacerda, MB, de França and Schultz CL 2018. A new erpetosuchid (Pseudosuchia, Archosauria) from the Middle–Late Triassic of Southern Brazil. Zoological Journal of the Linnean Society, zly008. https://doi.org/10.1093/zoolinnean/zly008
Maisch MW; Matzke AT; Rathgeber T 2013. Re-evaluation of the enigmatic archosaur Dyoplax arenaceus O. Fraas, 1867 from the Schilfsandstein (Stuttgart Formation, lower Carnian, Upper Triassic) of Stuttgart, Germany. Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen. 267 (3): 353–362.