Naranius americanus, Beard & Dawson, 2009

Ting, Suyin, Wang, Xiaoming & Meng, Jin, 2023, Cranial And Postcranial Morphology Of The Insectivoran-Grade Mammals Hsiangolestes And Naranius (Mammalia, Eutheria) With Analyses Of Their Phylogenetic Relationships, Bulletin of the American Museum of Natural History 2023 (463), pp. 1-129 : 94

COMMENTS oN NARANIUs AMERICANUs

The genus Naranius has been known as an Asian endemic taxon. It is represented by the type species, N. infrequens , which was discovered from the early Eocene Bumban Member of the Nemegt Formation, Mongolia, and the new species, N. hengdongensis , which was from the early Eocene Lingcha Formation of the Hengyang Basin, Hunan Province, China. Naranius americanus is the only reported species of Naranius outside Asia. The holotype of N. Americanus , a left m3 (CM 81283), and a referred specimen with right m2 (CM 81282), were collected from the upper part of the Tuscahoma Formation, Lauderdale County, Mississippi (early Wasatchian of the Gulf Coastal Plain; Beard and Dawson, 2009). The authors refer the specimen to the genus Naranius basically because of its small size and some similarities of lower molars to that of N. infrequens , such as “relatively tall trigonids and long talonids of the lower molars, the open lingual margins of the lower molars, and the relatively small size of the lower molar paraconids which are nonetheless located fairly high on the trigonid, near the base of the corresponding metaconid” ( Beard and Dawson, 2009: 204). The similarities that the authors mentioned above are mainly primitive characters that occurred in many early insectivorans. N. americanus differs from N. infrequens in having the m2 talonid longer, cristid obliqua of m2 and m3 labially located, indistinct hypoconulid of m2, and less open lingual side of the talonid. The most characteristic feature for Naranius is the considerably reduced and small P2–3 and p2–3, for which we are not aware in N. americanus . Also, we do not have any information on the upper dentition of N. americanus . The classification of N. americanus is very uncertain based on available evidence.