Pampadromaeus and Panphagia

Pampadromaeus barberenai (Cabriera et al. 2011; Langer et al. 2019' Late Triassic, Brazil) was originally described as a stem sauropodomorph known from a partial disarticulated skeleton and most of the skull bones. The authors reported, "Based on four phylogenetic analyses, the new dinosaur fits consistently on the sauropodomorph stem, but lacks several typical features of sauropodomorphs, showing dinosaur plesiomorphies together with some neotheropod traits."

Here, Pampadromaeus was the last common ancestor of Ornithischia + Sauropodomorpha. Pampadromaeus was small (slightly longer than a meter in length) biped with a generalized basal dinosaur morphology.

The skull of Pampadromaeus Note the length of the premaxillary teeth and their proximal exposure.

Pampadromaeus is a key taxon linking theropods to all other dinosaurs, the herbivorous Phytodinosauria. The enlargement of the premaxillary teeth observed in Daemonosaurus has its genesis in Pampadromaeus. The torso was shorter than in Saturnalia. The ilium resembled that of Herrerasaurus and Sanjuansaurus. The dorsal spines were lower than in Herrerasaurus. More detailed comparison can be found in Cabriera et al. (2011).

Cabriera et al. (2011) added Pampadromaeus to four prior studies and in each case Pampadromaeus nested as a sister to Sauropodomorpha or as a sister to Saturnalia + Sauropodomorpha. Only ten taxa were included in each test. In each study Silesaurus + Ornithischia were outgroup taxa.

Pampadromaeus is featured in

Panphagia protos Martinez and Alcobar (2009) described a small, basal Triassic dinosaur that nested at the base of the Sauropodomorpha. Panphagia matched Pampadromaeus. If not conspecific, the two appear to be congeneric. Panphagia protos has seniority. The ilium is more robust in Pampadromaeus. The scapula is more robust in Panphagia. Both nested between theropods and phytodinosaurs, basal to Daemonosaurus. The pubis in lateral view is very slender (but not in anterior view). This is the first clue I've seen as to the origin of the retroverted slender pubis in Ornithischia.

Cabreira SF, Schultz CL, Bittencourt JS, Soares MB, Fortier DC, Silva LR and Langer MC 2011. New stem-sauropodomorph (Dinosauria, Saurischia) from the Triassic of Brazil. Naturwissenschaften (advance online publication) DOI: 10.1007/s00114-011-0858-0

Langer MC, McPhee BW, Marsola JCdA, Roberto-da-Silva L, Cabreira SF 2019. Anatomy of the dinosaur Pampadromaeus barberenai (Saurischia—Sauropodomorpha) from the Late Triassic Santa Maria Formation of southern Brazil. PLoS ONE 14(2): e0212543.
https://doi.org/10.1371/journal.pone.0212543

Martínez RN and Alcober OA 2009. A basal sauropodomorph (Dinosauria: Saurischia) from the Ischigualasto Formation (Triassic, Carnian) and the early evolution of Sauropodomorpha (pdf). PLoS ONE 4 (2): 1–12. doi:10.1371/journal.pone.0004397. PMC 2635939. PMID 19209223. online article

wiki/Panphagia
wiki/Pampadromaeus

Phytodinosauria

Eodromaeus

Eoraptor • Panphagia

Pampadromaeus

Sauropodomorpha