title: A detailed assessment of the maxillary morphology of Limnopithecus evansi with implications for the taxonomy of the genus.
abstract: Limnopithecus is a small-bodied catarrhine genus that is widespread throughout early Miocene sites in East Africa. Although two species of this genus have been described - Limnopithecus legetet (type species) and Limnopithecus evansi - they are poorly known anatomically and their systematic positions remain unresolved. Here, we provide detailed descriptions and comparisons for two well-preserved maxillary specimens that we attribute to L. evansi. These specimens come from the type locality of the species, Songhor in western Kenya, and add greatly to our knowledge of its dentognathic morphology. Together, they preserve the entire unilateral upper dentition, with overlapping elements demonstrating conspecificity, and provide new information about I(2) morphology and aspects of the palate, nasal aperture, and maxillary sinuses. Detailed morphological comparisons suggest that specimens referred to Limnopithecus from Songhor, Koru, and Rusinga share a unique I(2) morphology not found in any other early Miocene catarrhine. This argues in favor of congeneric status for L. evansi and L. legetet. Moreover, features such as a broad palate, premolar morphology, and the relative proportions of the premolars of L. evansi distinguish it from Lomorupithecus harrisoni, another early Miocene catarrhine from Napak, Uganda. This finding challenges a recently proposed taxonomic interpretation that Lomorupithecus and L. evansi are conspecific. Our results underscore the distinctiveness of L. evansi and Lo. harrisoni, thereby reaffirming the validity of the taxon Lo. harrisoni and indicating that the Songhor and Napak catarrhine communities were relatively distinct, despite their apparent contemporaneity.
authors.affiliation: Department of Anthropology & Archaeology, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada. Electronic address: scote@ucalgary.ca.
authors.forename: Susanne
authors.initials: S
authors.lastname: Cote
authors.affiliation: Department of Anthropology, University of Minnesota, 301 19th Avenue South, Minneapolis, MN 55421, USA. Electronic address: kmcnulty@umn.edu.
authors.forename: Kieran P
authors.initials: KP
authors.lastname: McNulty
authors.affiliation: Department of Biomedical Sciences, Ohio University, 228 Irvine Hall, Athens, OH 45701, USA. Electronic address: stevensn@ohio.edu.
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Stevens
authors.affiliation: Department of Anthropology, De Anza College, 21250 Stevens Creek Blvd, Cupertino, CA 95104, USA. Electronic address: nengoisaiah@fhda.edu.
authors.forename: Isaiah Odhiambo
authors.initials: IO
authors.lastname: Nengo
mesh_terms: D000818:Animals; D051079:Catarrhini / Q000033:anatomy & histology* / Q000145:classification*; D005580:Fossils / Q000033:anatomy & histology*; D007630:Kenya; D008437:Maxilla / Q000033:anatomy & histology*; D010163:Paleontology; D010802:Phylogeny
keywords: Catarrhini; Kenya; Lomorupithecus; Napak; Songhor; Tinderet