Fraser-King et al. 2019
bring us new data on Styracocephalus (Fig. 3), a purported dinocephalian therapsid from Late Permian South Africa. Unfortunately the Fraser-King et al. phylogenetic analysis (Fig. 1) excludes relevant taxa (like Phthinosuchus) and includes one unrelated taxon, Tetraceratops. The authority for this criticism is a larger study, the therapsid skull tree (TST, 72 taxa, subset Fig. 2) a side branch of the large reptile tree (LRT, 1579 taxa). It includes the relevant taxa in the Fraser-King et al. study, and many more excluded from Fraser-King et al.
Both the holotype of Styracocephalus
and the new referred specimen nest together in the LRT despite their many morphological differences (Fig. 3). Even so, I think the differences are strong enough to erect a new genus for the new specimen. The two nest with the Phthinosuchus clade in the LRT, a taxon not included in the Fraser-King et al. study.
So, in this case,
I’m a splitter, not a lumper. And I wish Fraser-King et al. had included a few more taxa.
Fraser-King S, Benoit J, Day MO and Rubidge BS 2019. Cranial morphology and phylogenetic relationship of the enigmatic dinocephalian Styracocephalus platyrhynchus from the Karoo Supergroup, South Africa. Palaeontologia africana 54: 14–29.