I hate seeing this week-long experiment drag out like this…
but there is a lot of work here and slow, but steady progress. Still not finished. Thought you’d like to see the progress and transformation of the cladogram (Fig. 1). Click the [previous] button above to see earlier iterations of this work.
Re-scoring a reduced Nesbitt et al. 2017 matrix
A surprisingly large number of data matrix boxes in Nesbitt et al. 2017 were left unfilled, so I’m filling them. The resulting cladogram (Fig. 1) is getting to look more and more like the large reptile tree (LRT, 1560 taxa). Of those scores that needed to be re-scored, most were perplexingly obvious.
The clade Phytodinosauria
now nests derived from the Herrerasaurus clade, as in the LRT. The Silesaurus clade now nests within the Poposauria, as in the LRT. The next step is to figure out what is attracting giant terminal taxa in the Rauisuchia, like Postosuchus, to some much smaller, not-quite-basal Crocodylomorpha (Fig. 1) in Nesbitt et al. 2017 (Fig. 1), contra the LRT. This traditional attraction, creating the invalidated clade Pseudosuchia, is the basis for including many more clades in the Archosauria than just the crocs + dinos, as recovered in the LRT.
Here’s a Nesbitt et al. 2017 character I thought oddly worded:
“Maxilla ventral portion: Mediolateral height greater than dorsoventrally length.” Typically mediolateral refers to width. Dorsoventral refers to height. Data entries like this I just left alone.
I will get to the comments
from the past week once this project reaches a conclusion. Sorry for the delay. I’d rather not answer to anything posted until the entire experiment is finished and all the pertinent images are uploaded (apparently server issues prevent this currently).
Nesbitt SJ 2011. The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History 352: 292 pp.
Nesbitt S et al. 2017. The anatomy of Teleocrater Rhadinus, an early avemetatarsalian from the lower portion of the Lifua Member of the Manda Beds (Middle Triassic). Journal of Vertebrate Paleontology 142-177. https://doi.org/10.1080/02724634.2017.1396539