Titanoides: a rarely studied, but key mammal

Titanoides is rarely studied.
And it (Fig. 1) nests at the base of all large herbivorous mammals in the LRT (Fig. 2). That makes it more interesting than just another pantodont with a much smaller tail and larger canines than its phylogenetic sister, Barylambda nesting at the base of the Xenarathra (Fig. 2).

Figure 1. Titanoides nests between Barylambda (basal Xenarthra) and higher mammalian herbivores.

Figure 1. Titanoides nests between Barylambda (basal Xenarthra) and higher mammalian herbivores.

Titanoides primaevus (Gidley 1917; Late Paleocene, 58 mya; 3m in length) was originally considered a type of brontothere, but is now traditionally considered a pantodont mammal. Sabertooth canines mark this otherwise bear-like and bear-sized herbivore. Distinct from sister taxa, it had clawed digits. The skull was more than twice as wide as tall. Three premolars looked very much like molars. The jugal/zygomatic arch was slender and weak. The tail was a short vestige. Take a look at that odd lower canine (Fig. 1 orange tooth) with a concavity to accommodate the upper canine.

Figure 3. Subset of the LRT focusing on mammals. Titanoides nests at the base of all large herbivores.

Figure 3. Subset of the LRT focusing on mammals. Titanoides nests at the base of all large herbivores.

Sharp-eyed observers
will see a few very minor taxon shifts in the LRT (Fig. 2). This is what happens when more taxa are added. I also reexamined several poor scores and found a few errors that further cemented and slightly shifted a few relationships.

Happy holidays, everyone!
It’s gratifying to see a growing list of subscribers and readers. I wish you all the best!

References
Gidley JW 1917. Notice of new Paleocene mammal, a possible relative of the Titanotheres. Proceedings of the United States National Museum 52(2187):431-435.

wiki/Titanoides

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