We still need to add more taxa to our matrices.
Case in point:
Cisneros et al. 2015, is a recent paper on Tiarajudens (Fig. 4) behavior. Their cladogram (Fig. 1) does not match a larger study (Fig. 2) with regard to the way they ordered basal therapsids.
Two problems right at the start:
Everyone knows Dimetrodon is not basal to therapsids. It is far too derived. No basal therapsid has dorsal spines.
There’s a body of work that demonstrates that Tetraceratops is not a basal therapsid. Again, it is too derived, too bizarre, too different — and it does not nest with synapsids! In the large reptile tree it nests with Tseajaia. Actual basal therapsids include Cutleria and Biarmosuchus, which Cisneros et al. did use. Even so, they missed several taxa listed here (Fig. 3). Every taxon counts and adds value to the tree.
Adding taxa is a chore.
So, is that why paleontologists don’t like to add any more than they have to? It seems they often ask a grad student to do the work, and they’re new at it! They’re not experts until after they’ve done their studies. Workers can always reference the large reptile tree (Fig. 3). It works in whole or in part.
Anomocephalus and Tiarajudens
are giant, terrestrial dromasaurs, a clade of otherwise small, long-tailed, arboreal anomodonts. Giant dromasaurs converge with dicynodonts in several regards (short toes, tusks, size). Perhaps that leads to confusion generally.
Biseridens has nothing to do with basal anomondonts. It’s a derived dinocephalian (Fig. 3) when more taxa are added. Let’s get that straight, too.
Cisneros JC, Abdala F, Jashashvili T, de Oliveira Bueno A and Dentzien-Dias P 2015. Tiarajudens eccentricus and Anomocephalus africanus, two bizarre anomodonts (Synapsida, Therapsida) with dental occlusion from the Permian of Gondwana.