Spalacotherium evansae Ensom & Sigogneau-Russell, 2000

Allain, Ronan, Vullo, Romain, Rozada, Lee, Anquetin, Jérémy, Bourgeais, Renaud, Goedert, Jean, Lasseron, Maxime, Martin, Jeremy E., Pérez-García, Adán, Fabrègues, Claire Peyre De, Royo-Torres, Rafael, Augier, Dominique & Bailly, Gilles, 2022, Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J / K boundary, Geodiversitas 44 (25), pp. 683-752 : 730

Spalacotherium evansae Ensom & Sigogneau-Russell, 2000

( Fig. 34A, B )

DESCRIPTION

Three teeth of Spalacotheriidae have been recognized including two molars, which have the characteristic “symmetrodont” pattern with acute angulation of the principal cusps, seen in other spalacotheriids ( Fig. 34A ; Kielan-Jaworowska et al. 2004). The best preserved of the molars ANG M-26 lacks the posterior root and the hypoconulid (cusp d) ( Fig. 34A, B ). The protoconid, the metaconid and the paraconid are welldeveloped. The talonid was probably much reduced. Mesially, a single cusp e is lingually placed on the cingulid ( Fig. 34B ), and allows the identification of this tooth as a left lower molar. ANG M-26 is very similar, if not identical, to a tooth referred to Spalacotherium evansae (DORC GS 360, Ensom & Sigogneau-Russell 2000). Its smaller size compared to that of the molars of other species of Spalacotherium , the incompleteness of the labial cingulid associated with the equivalent height of the paraconid and metaconid, are diagnostic features (Ensom & Sigogneau-Russell 2000), that allow us to assign this specimen to Spalacotherium evansae . The latter species has been decribed from various localities of the Purbeck Group, including the Berriasian Lulworth Formation at Sunnydown Farm, U.K.

Figures

FIG. 34. — Trechnotherian mammal teeth from the Berriasian of Angeac-Charente: A, B, left lower molar of Spalacotherium evansae Ensom & Sigogneau-Russell, 2000 (ANG M-26) in occlusal (A) and lingual (B) views;C, D, left lower molar (m1 or?m2) of Dryolestidae indet.(ANG M-05) in occlusal (C) and linguodistal (D) views; E, F, left lower molar (m6 or?m7) of Dryolestidae indet. (ANG M-01) in occlusal (E) and mesial (F) views; G-I, left lower molar (m3?) of Peramus sp. (ANG M-25) in occlusal (G) labial (H) and lingual (I) views. Scale bars: 400 µm.