Kenyapotamus ternani

Boisserie, Jean-Renaud, Lihoreau, Fabrice, Orliac, Maeva, Fisher, Rebecca E., Weston, Eleanor M. & Ducrocq, Stéphane, 2010, Morphology and phylogenetic relationships of the earliest known hippopotamids (Cetartiodactyla, Hippopotamidae, Kenyapotaminae), Zoological Journal of the Linnean Society 158 (2), pp. 325-366 : 345

KENYAPOTAMUS TERNANI PICKFORD, 1983

Kenyapotamus ternani ; Pickford, 1983: 202, figs 13–

16, pl. 1 (fig. 3). Palaeopotamus ternani (Pickford, 1984) ; Pickford,

2007b: 99–101, figs 5–6.

Geographical distribution: Kenyan Rift, Kenya, eastern Africa.

Temporal distribution: Middle Miocene, roughly between 16 and 13.5 Mya.

Attributed material: Fort Ternan: KNM-FT 3322 (left M 3); KNM-FT 3934 (right M 1 – holotype); KNM-FT 19089 (right P 2). Kipsaramon: Bar 211 ′ 02 (left P 3); Bar 759 ′ 02 (right dP 4) †; Bar 821 ′ 01 (left M 2) †; Bar 977 ′ 02 (left P 2) †; Bar 978 ′ 02 (left dP 4) †; Bar 1186 ′ 99 (left M 1) †; Bar 1458 ′ 01 (left M 1) †; Bar 2680 ′ 03 (mesial half of lower? molar); Bar 2171 ′ 01 (left M 3); Bar 2681 ′ 03 (left dP 3) †; KNM-TH 31008 (right lower canine fragment). Maboko: KNM-MB 864 (left M 1 or M 2); KNM-MB 865 (M 1 or M 2); KNM-MB 866 (right M 2); KNM-MB? (right P4, Pickford, 1983: fig. 16) †. † indicates material attributed to K. ternani in the original publications ( Pickford, 1983, 2007b) not directly observed in this work.

Emended diagnosis: Size smaller compared to K. coryndonae ; no deep median indentation of P 3 labial cervix; upper molars with parastyle not mediomesial, distinct from mesiostyle; presence of salient postectohypocristid on lower molars more frequent than in K. coryndonae .

Discussion: The proposed specimen attributions to K. ternani mostly follow Pickford (2007b). Two new specimens were identified, bringing additional information: the fragmentary lower canine KNM-TH 31008 from Kipsaramon collected by the Baringo Paleontological Research Project, and the P 2 from Fort Ternan, KNM-FT 19089. However, the previous attribution of two specimens from Kipsaramon to K. ternani ( Pickford, 2007b) is considered to be uncertain. The unusual morphology of the left P 4 Bar 758 ′ 02 led us to refer it to K. cf. ternani , until the association to K. ternani of such P 4 morphology can be clearly demonstrated. The upper molar (?) Bar 1459 ′ 01 appears too fragmentary to warrant a certain attribution. It also seemed more cautious to identify it as K. cf. ternani .