Gondwanax, a new dinosauromorph from the Triassic of Brazil

[Halichoeres]

As with most silesaurid-type animals, it's pretty fragmentary, but it's a datum showing that they were once reasonably diverse, at least in some parts of the world.

A diagram with known elements in orange:

Gondwanax paraisensis

Appears to be open access in Gondwana Research: https://doi.org/10.1016/j.gr.2024.09.007

[Primeval12]

CollectA figure when?

[Halichoeres]

CollectA figure when?

They are pretty much the only company I can imagine making a silesaurid, but even then I'd put the odds low-ish.

[VD231991]

When put in the context of the cladistic analysis of Gondwanax by Müller, the presence of three sacral vertebrae in Gondwanax and Silesaurus in contrast to other silesaurids demonstrates that early ornithischians had the same number of sacrals as herrerasaurids and the most primitive sauropodomorphs (e.g. Guaibasaurus and Saturnalia), in which case an increase in the number of sacral vertebrae was prevalent among silesaurids most closely related to typical ornithischians. In fact, Pisanosaurus has hindlimb characters similar to those of silesaurids rather than Lesothosaurus, thyreophorans, or neornithischians despite having craniodental characters more derived than those of Lesothosaurus, in which case Sulcimientosauria could best described as partly characterized by the acquisition of three or more sacrals.

[ceratopsian]

Not open access - it's paywalled in fact.

[Halichoeres]

I could swear it was when I posted, sorry about that! If anyone wants the pdf, just send me a message or email.