Early Palaeogene Louisinidae (Macroscelidea, Mammalia), their relationships and north European diversity Author Hooker, Jerry J. Author Russell, Donald E. text Zoological Journal of the Linnean Society 2012 2012-03-20 164 4 856 936 http://dx.doi.org/10.1111/j.1096-3642.2011.00787.x journal article 10.1111/j.1096-3642.2011.00787.x 0024-4082 5407240 GENUS GIGARTON GEN. NOV. Type species: Gigarton meyeri sp. nov. , late Thanetian, Cernaysian ELMA , Cernay, Berru . Included species: Gigarton sigogneauae sp. nov. , late Thanetian, Cernaysian ELMA , Cernay, Berru. Gigarton pellouini sp. nov. , late Thanetian, Cernaysian ELMA , Cernay, Berru. Etymology: From the Greek gigarton , grape-stone, in allusion to the size and general shape of the teeth and their provenance in the vineyard region of Champagne. Neuter. Diagnosis: Louisinidae with cheek teeth with semibulbous to bulbous cusps and variably weak crests. P 4 molariform with equal-sized paracone and metacone, large hypocone. P 4 postmetacrista short and mesiodistally orientated (shared with Dipavali ). P 3 with low talonid basin with hypoconid, hypoconulid, and entoconid. P 4 with: gently sloping paracristid, with virtually no paraconid, and metaconid much lower than protoconid (shared with Dipavali ); talonid as wide as and nearly as high as trigonid, with hypoconid, hypoconulid, and entoconid. M 1–2 with: metacone larger than paracone; mesially pointed parastyle (shared with Berrulestes and Dipavali ); weak to absent postflexus; central valley longitudinally grooved (shared with Thryptodon ); paraconule absent; metaconule weak to absent. M 1–2 centrocrista buccally concave and distal cingulum dipping basally in middle (shared with Dipavali ). M 1 paraconid represented by faint, low, mesial cingulid. M 1 with: metaconid much smaller than protoconid; talonid with cristid obliqua with steep main slope (shared with Dipavali ); mesially positioned hypoconid. (Lower teeth and premolars are unknown for G. louisi , but generic characters inferred for all three species.) Figure 17. Scanning electron micrographs of gold-palladium coated epoxy casts of teeth of Gigarton meyeri gen. et sp. nov. , late Thanetian, France. A, LP 3 ?, Cernay (MNHN.F.CR-284-L). B, LP 3 ?, bed 4, Berru (MNHN.F.BRL-143-P). C, LP 4 , Cernay (MNHN.F.CR-11909). D, LM 1 , Cernay (MNHN.F.CR-318). E, holotype LM 2 , bed 4, Berru (MNHN.F.BRL-10-G). F, LP 3 , Cernay (MNHN.F.CR-1211). G, RP 4 (reversed), Cernay (MNHN.F.CR-1159). H, LM 1 , Cernay (MNHN.F.CR-4331). I, RP (reversed), Cernay (MNHN.F.CR-1696-Pn. J, RP (reversed), Cernay (MNHN.F.CR-946). K, LP 4 , Cernay 4 4 (MNHN.F.CR-6-Bn). L, LM 1 , bed 5, Berru (MNHN.F.I-251). M, RM 1 (reversed), Cernay (MNHN.F.CR-971-Pn). N, RDP 4 (reversed), Cernay (MNHN.F.CR-340-Ph). Views are: buccal (A, B1, C1, D1, E1, F2, G2, H2, I2), occlusal (B2, C2, D2, E2, F1, G1, H1, I1, J–N), and lingual (F3, G3, H3, I3). Scale bar = 2 mm. ›