Melaneremia Hooker, 2007

Hooker, Jerry J., 2012, A new omomyid primate from the earliest Eocene of southern England: First phase of microchoerine evolution, Acta Palaeontologica Polonica 57 (3), pp. 449-462 : 449-451

Genus Melaneremia Hooker, 2007

Type species: Melaneremia bryanti Hooker,2007 from the Lessness Shell Bed , Blackheath Formation , Early Ypresian , Eocene , Abbey Wood, London, UK .

Included species: Melaneremia schrevei sp. nov.

Emended diagnosis.—Small microchoerine (mean m1 length 1.82 mm). Lower dental formula:?? 3 3. Cheek teeth relatively low−crowned and essentially without enamel wrinkling. P3 buccolingually long with short postmetacrista and tiny sublingual protocone (unique). p3 similar in size to p4, both with high, cuspate paraconids. p4 lacking exodaenodonty, with talonid relatively long and with lingual crown base horizontal. Upper molars transversely elongate with short, mesiodistally orientated postmetacrista, with distinct postcingulum and metacingulum, and without Nannopithex fold or mesostyle. Lower molars with paraconid as large as metaconid and with mesiodistally orientated pre−entocristid. m1 trigonid open lingually. m1–2 entoconid slightly lower than metaconid. m2 distinctly longer than broad. m3 as long as m2. m3 talonid narrower than trigonid, with entoconid not lingually salient. m3 hypoconulid lobe unicuspid, broadly open to rest of talonid.

Differential diagnosis.—All other microchoerine genera ( Nannopithex Stehlin, 1916 , Vectipithex Hooker and Harrison, 2008 , Necrolemur Filhol, 1873 , Microchoerus Wood, 1844 , Pseudoloris Stehlin, 1916 , but unknown in Paraloris Fahlbusch, 1995 ) have a P3 with a larger, lingually positioned protocone. All except Paraloris are higher−crowned and (where known) have a less transversely elongate M1. All except Pseudoloris parvulus ( Filhol, 1890) are larger. Necrolemur has an m3 shorter than m2. All except Nannopithex zuccolae have an M1–2 hypocone. All except Pseudoloris , Vectipithex smithorum Hooker and Harrison, 2008 and V. ulmensis ( Schmidt−Kittler, 1971) have an upper molar Nannopithex fold. All except Pseudoloris and Paraloris have wrinkled enamel, intensely so in Necrolemur and Microchoerus . Necrolemur and Microchoerus have a larger, doubled upper molar metaconule, a bicuspid m3 hypoconulid lobe, and lack a paraconid on m2–3. Most Microchoerus have an upper molar mesostyle. Nannopithex zuccolae and Vectipithex have a p3 much smaller than p4. All except Vectipithex have a lower p3 paraconid. Necrolemur , Microchoerus , and Paraloris have a lower p4 paraconid. Nannopithex has an inflated p4. Nannopithex and Vectipithex have an exodaenodont p4. All except Paraloris have a p4 with a shorter talonid and with a mesially upward sloping lingual crown base. All except Nannopithex have lower molar paraconids distinctly smaller than metaconids and a lingually closed m1 trigonid. Vectipithex raabi ( Heller, 1930) , Nannopithex , Necrolemur , and Microchoerus have lower molars with pre−entocristid angled mesiobuccally. Nannopithex , Vectipithex , Necrolemur , and Microchoerus have an m2 nearly as broad as long. Nannopithex , Vectipithex , and Microchoerus have an m3 talonid wider than the trigonid; these plus Necrolemur have the m3 entoconid salient lingually. Pseudoloris has a longer, distobuccally angled M1 postmetacrista, an elongate p3, and an m1–2 entoconid as tall as the metaconid. Paraloris and Pseudoloris have a narrower m3 hypoconulid lobe.

The phenetically similar omomyine Jemezius Beard, 1987 differs from Melaneremia in having: a larger, lingually positioned P3 protocone; exodaenodont p4 with short talonid; M1–2 with distobuccally angled postmetacrista; buccolingually wide M3; lingually closed m1 trigonid; lower molar paraconid distinctly smaller than metaconid; m2–3 paraconid lingually situated and separated mesially from paracristid by a valley; and higher−crowned molars with a mesiobuccally angled pre−entocristid.

All species of the paraphyletic omomyid genus Teilhardina Simpson, 1940 differ in having: P3 with larger, lingually positioned protocone; M1–2 with distobuccally angled postmetacrista; taller p3–4; lower molars higher−crowned, with distal wall of trigonid steeper and paraconid distinctly smaller than metaconid; m1 with trigonid closed lingually and with straight, shallowly notched protocristid; m2–3 paraconid more lingually situated. For other differences from individual species of Teilhardina and from other primitive, non−microchoerine omomyids, see Appendices 1 and 2.