Long-lost relatives: Meniscotheriumm, Ocepeia and Orthaspidotherium

These three taxa
(Fig 1) have bounced around the LRT until recently finding each other as long-lost relatives.

Middle Palaeocene Ocepeia
(Gheerbrant et al 2014) is known from most of the skull and mandible (Fig 1). The anterior teeth and rostrum are taphonomically absent. Originally it was considered an Afrotherian placental.

Afrotheria is a genomic clade, here applied to a fossil.

FIgure 1. Ocepeia, Meniscotherium and Orthaspidotherium, all marsupials now in the LRT. ” data-image-caption=”

FIgure 1. Ocepeia, Meniscotherium and Orthaspidotherium, all marsupials now in the LRT.

” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/11/ocepeia_meniscotherium_skull588.jpg?w=111″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/11/ocepeia_meniscotherium_skull588.jpg?w=380″ class=”size-full wp-image-89842″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/11/ocepeia_meniscotherium_skull588.jpg” alt=”FIgure 1. Ocepeia, Meniscotherium and Orthaspidotherium, all marsupials now in the LRT.” width=”584″ height=”1573″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/11/ocepeia_meniscotherium_skull588.jpg?w=584&h=1573 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/11/ocepeia_meniscotherium_skull588.jpg?w=56&h=150 56w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/11/ocepeia_meniscotherium_skull588.jpg?w=111&h=300 111w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/11/ocepeia_meniscotherium_skull588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

FIgure 1. Ocepeia, Meniscotherium and Orthaspidotherium, all marsupials now in the LRT.

Wikipedia cited Gheerbrant et al 2014 when it reported,
“In body mass and skull size, O. daouiensis is similar to modern-day hyraxes and the extinct Meniscotherium.”

In the original phylogenetic analysis,
Gheebrant et al reported, “Ocepeia has a basal position in the trees, outside the
Paenungulata, ‘‘Altungulata’’ (lophodont ungulates) and ‘‘Taxeopoda’’. It most frequently belongs to a basal afrotherian clade together with Potamogale, Ptolemaia, Orycteropus, corresponding to the molecular-based clade Afroinsectiphilia minus Macroscelidea, although in some case (e.g., unordered analysis) it is a more derived branch (sister group of all other taxa). Within Afroinsectiphilia, Ocepeia joins preferentially Potamogale (e.g., 148-1, postorbital process reduced), and Ptolemaia groups with Orycteropus in many of our analyses.”

Their figure 21 cladogram included many suprageneric taxa, but did not include Meniscotherium.

Their figure 22 cladogram nested Ocepeia with the shrew Potamogale.

Ocepeia daouiensis
(Gheerbrant et al 2001, 2014; Paleocene, 60 mya; 9 cm skull length) is from Morocco. Here it nests with Orthaspidotherium and Meniscotherium. The pneumatized skull contains many air spaces. Slightly larger skulls have larger canines and so are considered male, but may just be older. This specimen has only a tiny canine on a broken maxilla. The molar teeth are relatively large and the jugal deepens below the orbit, hiding the posterior molars in lateral view. Note the dorsal eyes, as in hippos. Ocepeia was found with aquatic taxa and was probably amphibious. The name Ocepeia derives from the initials of Office Chérifien des Phosphates (O.C.P.), the national Moroccan phosphate mining company.

Meniscotherium tapiacitum
(Cope 1874; Williamson and Lucas 1992; Middle Eocene 54-38 mya; 25-50 cm long) nests with Astrapotherium as marsupials derived from extant Monodelphis domestica.

All three of these taxa had high orbits and wide skulls, something like little hippos.

This appears to be a novel hypothesis of interrelationships.
If not, please provide a citation so I can promote it here.

References
Cope ED 1874. Report of the Chief of Engineers for. 1874 Vol. II, Pt. II, Appendix FFa of Appendix FF, pp. 115-130.
Gheerbrant E, Amaghzaz M, Bouya B and Goussard F and Letenneur C 2014. Ocepeia (Middle Paleocene of Morocco): The Oldest Skull of an Afrotherian Mammal. PLoS ONE. 9 (2): e89739. doi:10.1371/journal.pone.0089739.
Williamson TE and Lucas SG 1992. Meniscotherium (Mammalia, “Condylarthra”) from the Palaeocene-Eocene of Westeran North America. New Mexico Museum of Natural Hstory and Science Bulletin 1.

wiki/Meniscotherium
wiki/Ocepeia
wki/Orthaspidotherium