Etjosuchus is an extinct genus of "rauisuchian" (loricatan) archosaur from the Triassic of Namibia. It is known from a single species, Etjosuchus recurvidens, which is based on a partial skeleton from the Ladinian or Carnian-age Omingonde Formation.[1]

Etjosuchus
Temporal range: Middle-Late Triassic, Ladinian–Carnian
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauria
Clade: Pseudosuchia
Clade: Loricata
Genus: Etjosuchus
Tolchard et al., 2021
Type species
Etjosuchus recurvidens
Tolchard et al., 2021

Classification edit

To evaluate the evolutionary position of Etjosuchus in a modern context, Tolchard et al. (2021) coded it into a phylogenetic matrix derived from the work of Nesbitt (2011). The phylogenetic analysis was run with several levels of implied weighting (from no weighting to k=1, 3, and 6), a strategy to minimize the effects of homoplasy (convergent evolution). With no weighting, Etjosuchus is resolved as a basal loricatan closer to crocodylomorphs than Luperosuchus, but not as close as a Heptasuchus + Batrachotomus clade. At k=1, its position shifts crownward towards crocodylomorphs, and Etjosuchus may clade with Fasolasuchus and/or Rauisuchus. Increasing the weighting further strengthens a connection with Rauisuchus, crownward of Fasolasuchus. This would indicate that the family Rauisuchidae is a paraphyletic grade rather than a clade: Postosuchus and Polonosuchus, other proposed rauisuchids, were closer to crocodylomorphs than to Rauisuchus in this configuration.[1]

References edit

  1. ^ a b Tolchard, Frederick; Smith, Roger M. H.; Arcucci, Andrea; Mocke, Helke; Choiniere, Jonah N. (2021-08-25). "A new 'rauisuchian' archosaur from the Middle Triassic Omingonde Formation (Karoo Supergroup) of Namibia". Journal of Systematic Palaeontology. 19 (8): 595–631. doi:10.1080/14772019.2021.1931501. ISSN 1477-2019. S2CID 237402241.