Aardonyx (basal sauropodomorph) enters the LRT

Aardonyx celestae 
(Yates et al. 2010; Fig. 1) was originally considered a basal sauropodomodph dinosaur, because it is one.

Figure 1. Aardonyx from Yates et al. 2009. Colors added.

Figure 1. Aardonyx from Yates et al. 20109. Colors added.

In the large reptile tree (LRT, 1760+ taxa; subset Fig. 2) Early Jurassic Aardonyx nests with the Late Jurassic prosauropod, Saturnalia, a taxon not mentioned in the Yates et al. paper. Aardonyx is larger, more robust and has shorter feet, as in sauropods, making it a sauropod mimic.. so, not in the lineage of sauropods. That should be relatively uncontroversial.

Figure 2. Subset of the LRT focusing on basal phytodinosauria. Aardonyx nests with Saturnalia here.

Figure 2. Subset of the LRT focusing on basal phytodinosauria. Aardonyx nests with Saturnalia here.

 

References
Yates AM, Bonnan MF, Neveling J, Chinsamy A and Blackbeard MG 2010. A new transitional sauropodomorph dinosaur from the Early Jurassic of South Africa and the evolution of sauropod feeding and quadrupedalism. Proceedings of the Royal Society B. 277(1682): 787–794.

wiki/Saturnalia
wiki/Aardonyx

5 thoughts on “Aardonyx (basal sauropodomorph) enters the LRT

  1. “In the large reptile tree (LRT, 1760+ taxa; subset Fig. 2) Early Jurassic Aardonyx nests with the Late Jurassic prosauropod, Saturnalia, a taxon not mentioned in the Yates et al. paper.”

    I guess it wasn’t mentioned because it wasn’t relevant. Your result seem to suffer of taxon exclusion. Maybe try adding pertinent taxa, such as Plateosaurus, Thecodontosaurus, Lufengosaurus, Riojasaurus. Yates’ trees have 3+ times more Triassic/early Jurassic sauropodomorphs than yours. I’m curious about which traits nested both together, can you mention the synapomorphies?

    Also, I think it would be best if you reconstruct the animal with your own methods. I mean, you colorized several bones (in the skull) that are not known and thus they would’ve looked diferent if Aardonyx nested with Saturnalia as in your tree. So I’d like to see how It would look like. Could make its skeleton match that of Saturnalia? Moreover, could you update your Saturnalia with the recent skull bones and everything else? I believe only the dorsal vertebrae have not been figured yet in the literature.

    Not related to this topic: which taxon or specimen is the basalmost dinosaur in the LRT nowadays? I feel like every new Carnian dinosaur (I’m looking at you Gnathovorax and Buriolestes) is recovered as the basalmost dinosaur in the LRT, and then it isn’t anymore.

    I’d like to see your view of Bagualosaurus, Nhandumirim, and Unaysaurus as well.

    • Taxon exclusion is often a problem, Mauricio. Prosauropods are underrepresented here. When more are added things may change. I can only work with what I have at present. It’s step-by-step here, as you can appreciate. Thank you for the taxon suggestions. I have never heard of them.

      Mentioning synapomorphies leads to “Pulling a Larry Martin.” Convergence makes such lists subject to petty undercutting.

      re: basalmost dinosaurs… adding taxa changes things, as I’ve seen and said for the last ten years.

  2. I don’t understand this, science is about being proven wrong. EVERYONE should be flooding you with honest, no holds-barred data until you choke and then taking your LRT interpretation and crowing how you are just a stupid so and so.

    I think they are afraid of what the honest results may be.

    • If ‘they’ (other paleo workers) are at all interested in ‘results’, they can look to the large reptile tree, large pterosaur tree and therapsid skull tree for lists of pertinent taxa to test, confirm or refute using their own characters.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.