Agriochoerus latifrons, Megaladapis, Maganadapis and Adapis

Megaladapis insignis (Forsyth Major 1894, up to 1.5m in length) is the extinct koala lemur from Madagascar. The arms were longer than the legs. The snout remains unknown. Only three molars were present. Here it nests between Notharctus and the rest of the primates, but clearly has been evolving its koala-like shape for the entire Cenozoic.

Agriochoerus latifrons (Leidy 1850, 1869; Wortman 1895, O'Harra 1920, Late Eocene to Oligocene, 38–16mya, skeleton) has a distinctly different tooth pattern with large lateral incisors and a diastema. In the LRT, this taxon is the basalmost artiodactyl and shares an ancestry with Nasua, the extant coatimundi. Agriochoerus has slender, perhaps vestigial thumbs and is also found here with Lophiodon.

Adapis parisiensis (Cuvier 1821, Gingerich 1975, Eocene, 40mya; size) nests between Notharctus and Mandrill in the LRT. So, it is in the human lineage. Note the forward-facing eyes, smaller rostrum, larger canines, upturned premaxilla making room for large lower canines and incisors.

Magnadapis quercyi (Godinot and Couette 2008, MNHN QU 10875 Late Eocene, 11cm skull length) is a sister to Adapis in the LRT.

Cuvier GB 1822. Recherches sur les ossemens fossiles 3:265.

Gingerich PD 1975. Dentition of Adapis parisiensis and the evolution of lemuriform primates in I. Tattersall et al. (eds.), Lemur Biology. Plenum Press, NY.

Gingerich PD 1981. Cranial morphology and adaptations in Eocene Adapidae. I. Sexual dimorphism in Adapis magnus and Adapis parisiensis.

Gingerich PD and Martin RD 1981. Cranial morphology and adaptations in Eocene Adapidae. II. The Cambridge skull of Adapis parisiensis. American Journal of Physical Anthropology. 56 (3): 235–257. doi:10.1002/ajpa.1330560304

Godinot M and Couette S 2008. Morphological diversity in the skulls of large adapines (Primates, Adapiformes) and its systematic implications. in E. J. Sargis and M. Dagosto (eds.), Mammalian Evolutionary Morphology: A Tribute to Frederick Szalay

Major CIF 1894. On Megaladapis madagascariensis, an Extinct Gigantic Lemuroid from Madagascar; with Remarks on the Associated Fauna, and on Its Geological Age. Philosophical Transactions of the Royal Society B: Biological Sciences. 185: 15–38.

Major CIF 1900. Extinct Mammalia from Madagascar. I. Megaladapis insignis, sp. N. Philosophical Transactions of the Royal Society B: Biological Sciences. 193 (185–193): 47–50.

wiki/Adapis
wiki/Magnadapis
wiki/Megaladapis