Poebrotherium enters the LRT at the base of camels

Slender, two-toed Poebrotherium
(Figs 1, 2) is traditionally considered basal to camels. In the large reptile tree (LRT, 2060 taxa, subset Fig 6) Poebrotherium likewise nests basal to camels, which are basal to cattle, giraffids, sheep and deer in the LRT.

Figure 1. Poebrotherium skull. Colors added here. Note the lack of a diastema (= area lacking teeth), a trait typical of derived taxa. Note the umlauts are suppressed here, a rule just now brought to my attention.

Figure 2. Skeleton of Poebrotherium.

Here’s where the heresies kick in
Litolophus (Fig 3), a traditional crested chalicothere with small round hooves, now nests basal to camels in the LRT. The resemblance to Poebrotherium (Fig 2) is notable and more so than to any chalicothere or any other LRT taxon according to the scores.

Figure 3. Litolophus is a traditional chalicothere that nests basal to camels and kin in the LRT.

Basal to Litolophus
is Ectocion cedrus (Fig 4), a traditional phenacodontid. This smaller, more plesiomorphic taxon nests apart from Ectocion ralstonensis, which nests closer to hyraxes in the LRT. So these two are not congeneric.

Ectocion cedrus now links tall slender artiodactyls,
like Litolophus (Fig 3), camels, deer and cattle, to the clade of pigs, the other traditional artiodactyl clade, now somewhat separated from the camels by these two taxa (see Fig 6) that other workers did not consider to be basal artiodactyls.

Figure 4. Ectocion cedrus is the basalmost artiodactyl in the camel clade. Note its resemblance to the basalmost taxon in the pig clade, Cainotherium in figure 5.

Pig ancestors
include four-toed Cainotherium (Fig 5) a late surviving Late Eocene slender grazer, which greatly resembles Ectocion cedrus (Fig 4) from the Paleocene. These taxa are all part of the radiation of terrestrial herbivores following the K-Pg extinction event.

Figure 5. Cainotherium nests basal to the pig clade in the LRT.

Several placental taxa recently added to the LRT
(subset Fig 6) have clarified hypothetical interrelationships in the resurrected clade Condylarthra. Adding taxa always seems to shed new light here in the LRT and elsewhere.

Figure 6. Subset of the LRT focusing on condylathran placentals, all arising after the K-Pg extinction event and all showing trends toward terrestrial locomotion and herbivory. Some like goats and tree sloths have, one way or another, returned to the tree.

The LRT remains fully resolved
employing 2060 taxa tested using 236 multistate characters.

References
Prothero et al. (15 co-authors) 2021. On the Unnecessary and Misleading Taxon “Cetartiodactyla”. Journal of Mammalian Evolution. https://doi.org/10.1007/s10914-021-09572-7