Eurolagus López Martínez, 1977

Fostowicz-Frelik, Łucja, Nadachowski, Adam & Kowalewska-Groszkowska, Magdalena, 2012, New data on the Miocene stem lagomorph Eurolagus fontannesi, and its northernmost record, Acta Palaeontologica Polonica 57 (1), pp. 1-20 : 6

Genus Eurolagus López Martínez, 1977

Type species: Eurolagus fontannesi ( Depéret, 1887) , by monotypy; La Grive Saint−Alban ( Isère , France), Astaracian .

Diagnosis.—Large semihypsodont lagomorph, smaller than Megalagus and larger than Amphilagus antiquus , Desmatolagus , most species of Gobiolagus , Gripholagomys , Mytonolagus , Piezodus , and Titanomys , and all species of Palaeolagus , except the larger P. intermedius . More strongly hypsodont than most of the primitive stem lagomorphs, with a tooth crown height comparable to that of Megalagus and advanced Mytonolagus ( M. wyomingensis ), slightly lower than that of Amphilagus , and markedly lower than that of the semihypsodont species of Palaeolagus . Curvature of the upper teeth is definitely larger than in Palaeolagus , less than in the rootless Titanomys calmensis , and similar to that in Amphilagus , Desmatolagus , Megalagus , Mytonolagus , Titanomys visenoviensis , and Piezodus branssatensis . A trilobate P2 distinguishes Eurolagus from the basically bilobate tooth of Palaeolagus . P3 is not molarized, unlike that of Palaeolagus ; the lingual lobe of P3 is longer than in Amphilagus , Desmatolagus , Gobiolagus , and most of Mytonolagus , and more compressed anterodistally than in those genera and in Megalagus . P4 molarized unlike that of Gobiolagus and Lushilagus . Persistency of the enamel pattern on the upper cheek teeth separates Eurolagus from Lushilagus , Shamolagus , and Gobiolagus , in all of which the hypostriae are weak and the occlusal pattern wears relatively quickly. The hypostria is deeper than in Desmatolagus , and comparable to that of Mytonolagus and Megalagus ; it is relatively shallow on P3 and P4 (shallower than in Palaeolagus ) and cuts across one−third of the occlusal surface on M1 and M2. Hypostrial lakes are absent in Eurolagus , unlike in Palaeolagus , Megalagus , Mytonolagus , Gripholagomys , and Desmatolagus . The p3 is single−rooted, unlike the double−rooted tooth of Mytonolagus , Megalagus , and Strenulagus . The crown of p3 is bilobate and compact, with a short and relatively large trigonid, and a slightly concave anterolingual side in younger individuals, resembling in outline and proportions the p3 of Amphilagus antiquus , Megalagus , and Gripholagomys at most wear stages. This tooth further differs from that of Desmatolagus , which has a smaller trigonid, Mytonolagus , which has an enlarged trigonid, and Gobiolagus , Lushilagus , and Shamolagus , which have a trilobate p3. The lingual reentrant of p3 is much less persistent than in Titanomys , Palaeolagus , and some species of Mytonolagus . Together with the absence of an isolated anteroconid, this distinguishes Eurolagus from Piezodus . Differs from all genera (apart from Mytonolagus ) in having more persistent reentrants on the buccal instead of the lingual side of the talonids of the lower cheek teeth. The m2 has fused roots as in Amphilagus and Palaeolagus , unlike the condition in Megalagus and Mytonolagus . The m3 is reduced in comparison to that in Lushilagus , Shamolagus , and Gobiolagus and marked by two conids, unlike the m 3 in Amphilagus , Titanomys , and Piezodus (m3 with single conid). Both conids become fused late during ontogeny as in Desmatolagus , but unlike the condition seen in Megalagus and Palaeolagus . Eurolagus further differs from Gobiolagus , Lushilagus , Mytonolagus , and Shamolagus in having no trace of an additional lobe on m3.