Revisiting Anteosaurus ‘junior’

Earlier we looked at the Kruger et al. 2017 hypothesis
that specimen BP/1/7074 (Fig. 1) was a juvenile Anteosaurus (Fig. 1; Watson 1921). The Therapsid Skull Tree (TST, 67 taxa, Fig. 4). Here, with better skull data, BP/1/7074 still does not nest with Anteosaurus, but I completely understand the earlier hypothesis.

Figure 1. Anteosaurus magnifies compared to the smaller and coeval BP/1/7074 specimen others considered a juvenile. Other more closely related specimens in the TT are also shown alongside BP/1/7074 specimen.

Figure 1. Anteosaurus magnifies compared to the smaller and coeval BP/1/7074 specimen others considered a juvenile. Other more closely related specimens in the TT are also shown alongside BP/1/7074 specimen.

There are a variety of Anteosaurus skulls known.
Here (Fig. 2) is a second one, A. abeli, for comparison (no scale bars). Perhaps another Anteosaurus skull will attract BP/1/7074, but presently tested skulls do not yet do so. Titanophoneus potens (Fig. 1) still nests closer to Anteosaurus while coeval Australosyodon (Fig. 1) nests with BP/1/7074.

Figure 2. Anteosaurus abeli skull with right side grayed out and colors added.

Figure 2. Anteosaurus abeli skull with right side grayed out and colors added.

The whole concept of juveniles of larger genera
looking like neotonous adults of less related genera has a long history with basal therapsids. We looked at one example earlier here with tiny Abadalon.

Figure 6. Anteosaurus scale model.

Figure 3. Anteosaurus scale model.

The TST
(Fig. 4) has seen many score changes over the past weekend, yet remained the same… or almost the same. One taxon shown below will move over one node. I look forward to telling that story.

Figure 4. TST revised with new data on Patranomodon and sister taxa.

Figure 4. TST revised with new data on Patranomodon and sister taxa.

For those who really want to know…
Hipposaurus
will move to the base of the Anomodontia.


References
Boonstra LD 1963. Diversity within the South African Dinocephalia. S. Afr. J. Sci. 59: 196-206.
Kammerer CF 2011. Systematics of the Anteosauria (Therapsida: Dinocephalia).
–Journal of Systematic Paleontology: Vol. 9, #2, pp. 261-304.
Kruger A 2014. Ontogeny and cranial morphology of the basal carnivorous dinocephalian, Anteosaurus magnificus from the Tapinocephalus assemblage zone of the South African Karoo. Masters dissertation, University of Wiwatersand, Johannesburg.
Kruger A, Rubidge BS and Abdala F 2017. A juvenile specimen of Anteosaurus magnificus Watson, 1921 (Therapsida: Dinocephalia) from the South African Karoo, and its implications for understanding dinocephalian ontogeny. Journal of Systematic Palaeontology. http://dx.doi.org/10.1080/14772019.2016.1276106
Watson, DMS 1921. The Bases of Classification of the Theriodontia: Proceedings of the Zoological Society of London, 1921: 35-98.

wiki/Anteosaurus

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