What was Acaenasuchus?

[Halichoeres]

Acaenasuchus is a small archosaur that was previously known mostly from isolated osteoderms. Newly described skeletal materials fills in a lot of gaps, although it's far from a complete skeleton. Still, it's enough to place it as part of the sister group to aetosaurs and hypothesize a fair amount of its appearance.

If you're familiar with aetosaurs, a lot of this should look familiar:



Paper (paywall, but contact me for pdf): https://www.tandfonline.com/doi/full/10.1080/02724634.2020.1794885

[CityRaptor]

Yep, that looks a lot like my Bullyland Paratypothorax.

Still, it's enough to place it as part of the sister group to aetosaurs

I think there is a mistake here. It's an Aeotsaur.

[Newt]

Awesome! You know, it's becoming increasingly undeniable that the Adamanian is the best time in prehistory.

I think there is a mistake here. It's an Aeotsaur.

Parker 2007 (doi:10.1017/S1477201906001994) defines Aetosauria as 'a stem-based taxon that consists of all taxa closer to Aetosaurus and Desmatosuchus than to Leptosuchus, Postosuchus, Prestosuchus, Poposaurus, Sphenosuchus, Alligator, Gracilisuchus, and Revueltosaurus'. Since Acaenasuchus comes out closer to Revueltosaurus than to Aetosaurus or Desmatosuchus in this phylogeny, it is by definition not an aetosaur, no matter how much it may look like one. Of course, no phylogeny is final, so Acaenasuchus may yet regain its aetosaurian identity. However it goes, it's an interesting look at a critter formerly known only from isolated osteoderms (the potsherds of the Triassic).

[Halichoeres]

Awesome! You know, it's becoming increasingly undeniable that the Adamanian is the best time in prehistory.

The Fammenian would like word.


Anyway, here's an illustration of Newt's point about whether it's an aetosaur. In this analysis, it isn't, quite, but I'm sure this isn't the final word.

[Newt]

The Fammenian would like word.

Pfff, the Fammenian is a downgrade from the Frasnian. Acanthostega is no substitute for psammosteids! You know it's true.

Also, the Ornithosuchidae silhouette in the figure you posted reminds me of El Hombre Lagarto from The Goon.