Moeritherium, Radinskya and Phosphatherium

Radinskya yupingae (McKenna et al. 1989, Holbrook 2014; IVPP V-5255; Middle Paleocene; China) was originally considered a perissodactyl-like herbivore, but never with confidence. Here Radinskya nests in the sea cow clade, but much smaller than most of its relatives.. Note the tiny procumbent second incisor. The premolar is molariform.

Phosphatherium and Ectocion ralstonensis

Phosphatherium escuillei (Gheerbrant, Sudre and Cappetta 1996; Late Paleocene; 10cm skull length nests derived from Ectocion in the LRT, far from elephants. Two species are shown here.

Moeritherium lyonsi (Andrews 1901; Eocene, 36 mya; 70 cm tall at shoulder) nests here as an ancestor to sea cows, like Dusisiren. Moeritherium is derived from a sister to Radinskya.

The orbit was far forward, over the diatema. Huge jaw muscles filled the back half of the skull. The cervicals were long with robust fused ribs. A long torso, tiny tail and short limbs lacking feet, unfortunately, are parts known from bits and pieces of several specimens.

Andrews RC 1901 Tagebl. d. V. International Zool. Congr. Berlin 6: 41.

Andrews CW 1906. A Descriptive Catalogue of the Tertiary Vertebrata of the Fayûm, Egypt. Based on the Collection of the Egyptian Government in the Geological Museum, Cairo, and on the Collection in the British Museum (Natural History), London. 324 pp. Natural History Museum, London.

Gheerbrant E, Sudre J and Cappetta H 1996. A Palaeocene proboscidean from Morocco. Nature. 383 (6595): 68–71.

Gheerbrant E 2009. Paleocene emergence of elephant relatives and the rapid radiation of African ungulates. Proc Natl Acad Sci USA. 106(26): 10717–10721.

Gheerbrant E et al. 2005. Nouvelles données sur Phosphatherium escuilliei (Mammalia, Proboscidea) de l’Éocène inférieur du Maroc, apports à la phylogénie des Proboscidea et des ongulés lophodontes. Geodiversitas 27 (2), 2005, pp. 239-333.

Holbrook LT 2014. On the Skull of Radinskya (Mammalia) and Its Phylogenetic Position. Journal of Vertebrate Paleontology34(5):1203–1215.

Matthew WD 1937. Paleocene faunas of the San Juan basin, New Mexico. Transactions of the American Philosophical Society, new series 30: 1-510.

Matsumoto H 1923. A Contribution to the Knowledge of Mœritherium. Bulletin of the American Museum of Natural History 48(4): 97-140.

McKenna MC, Chow M, Ting S and Luo Z 1989. Radinskya yupingae, a perissodactyl-like mammal from the late Paleocene of China. In Prothero DR, Schoch RM The evolution of perissodactyls. Oxford monographs on geology and geophysics. 15. New York: Oxford

wiki/Radinskya
wiki/Phosphatherium
wiki/Moeritherium

Mammalia

Ornithorhynchus and kin

Marsupials - Metatheria

Eomaia and kin

Placentalia 2

Tupaia and kin

Placentalia 1

Primates – Chiroptera

Notharctus and kin

Carnivora

Nandinia and kin