Etjosuchus Temporal range: Middle-Late Triassic,
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Scientific 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
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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]
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]- ^ 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.