Isectolophus, Bemalambda and Arsinoitherium

Isectolophus scotti (Scott and Osborn 1887; Holbrook, Lucas and Emry 2004; Early Oligocene to Early Miocene) nests basal to the Arsinoitherium clade in the LRT.

Bemalambda nanhsiungensis (Chow et al 1973; Li 2005; early to middle Paleocene 60mya, China, 1m in length) was originally considered a pantodont. Here it isclose to Periptychius at the base of the Uintatherium clade. Note the clavicles. Seems to be an herbivore with those hooves and small dentition.

Bemalambda pachyoesteus is the middle image specimen. The left and right feet are interchanged on this mount.

Arsinoitherium zitteli (Beadnell 1902, Figs. 1, 2; late Eocene, early Oligocene, 36-30 mya) was a sister to Gobiatherium and derived from a sister to Coryphodon. Wikipedia describes Arsinoitherium as, "an extinct genus of paenungulate mammal belonging to the extinct order Embrithopoda. It is related to elephants, sirenians, hyraxes and the extinct desmostylians." That is not recovered in the LRT.

A trait that makes Arsinoitherium distinct is its nearly complete arcade of teeth, none of them tusks, 3 molars and the medial incisor is missing. The premaxilla redevelops an ascending process of the premaxilla, a trait not seen in mammals since their origin in the Triassic. Also seen in Gobiatherium.

Beadnell HGC 1902. A preliminary note on Arsinoitherium zitteli, Beadnell, from the Upper Eocene strata of Egypt. Public Works Ministry, National Printing Department. Cairo: 1–4.

Chow MM, Chang Y-P, Wang BY and Ting SY 1973. New mammalian genera and species from the Paleocene of Nanhsiung, N. Kwangtung. Vertebrata PalAsiatica 11(1):31-35.

Erdal O, Antoine -ø and Sen S2016. New material of Palaeoamasia kansui (Embrithopoda, Mammalia) from the Eocene of Turkey and a phylogenetic analysis of Embrithopoda at the species level. Palaeontology, 2016,

Li Q 2005. New material of Bemalambda from Chijiang Basin in Jiangxi, China. Vertebrata PalAsiatica 43(4):325-329.

Lucas SG 2001. Gobiatherium (Mammalia: Dinocerata) from the Middle Eocene of Asia: Taxonomy and biochronological Significance. Paläontologische Zeitschrift 74 (4): 591–600.

Holbrook LT, Lucas SG and Emry RJ 2004. Skulls of the Eocene perissodactyls (Mammalia) Homolgalax and Isectolophus. Journal of Vertebrate Paleontology 24(4):951–956.

Scott WB and Osborn HF 1887. Preliminary Report on the Vertebrate Fossils of the Uinta Formation, Collected by the Princeton Expedition of 1886. Proceedings of the American Philosophical Society 24(126):255-264.

wiki/Arsinoitherium
wiki/Isectolophus
wiki/Bemalambda

Mammalia - Monotremata

Ornithorhynchus

Marsupiala - Metatheria

Eomaia

Placentalia 1.1