Fossil fingers and toes are not known
for Anthracobune, but we have enough of it (Fig. 2) to nest it with Paleoparadoxia, as Cooper et al. did (Fig. 1). Unfortunately, Hippopotamus (four toes) was not tested by Cooper et al. In the large reptile tree, it nests with Paleoparadoxia and Anthracobune, all derived from a sister to Mesonyx (four toes), also not tested by Cooper et al. So Cooper et al. were right about Anthracobune having desmostylian affinities, wrong about having Equus affinities.
Hippos are considered artiodactyls (aka even-toed ungulates) along with giraffes, camels deer and pigs, but Wikipedia reports, “hippopotamuses are not closely related to these groups.” Here hippos and their kin are considered mesonychids, a clade of ungulates traditionally considered carnivorous and extinct. Here the tested ones are neither carnivorous nor extinct.
don’t have to be carnivores just because they have large canines. They are commonly regarded as ungulates and descendants of condylarths. No tested sister taxa are carnivores. And, as a reminder, mesonychids are not related to whales, tenrecs are (Fig. 4).
I continue to find it amazing how much the large reptile tree continues to diverge from traditional trees yet delivers sisters that look alike and have gradual accumulations of derived traits.
Cooper LN, Seiffert ER, Clementz M, Madar SI, Bajpai S, Hussain ST, Thewissen JGM 2014. Anthracobunids from the Middle Eocene of India and Pakistan Are Stem Perissodactyls. PLoS ONE. 9 (10): e109232. doi:10.1371/journal.pone.0109232. PMID 25295875.