Squamata Oppel, 1811

Squamata Oppel, 1811 View in CoL

Gekkota Cuvier, 1817

Gekkota indet.

Figure 6 View Fig

Material. Eight dentaries ( MHNT.PAL. 2023.0.31.118a– MHNT.PAL. 2023.0.31.118g, UM-BFI 3060, UM-BFI 3072, and UM-BFI 3090); one trunk vertebra ( UM-BFI 3195); and one sacral vertebra ( UM-BFI 3193).

Description

Dentaries: All dentaries are broken, with almost no teeth preserved ( Fig. 6a–f View Fig ). Te largest dentary (MHNT.

PAL.2023.0.31.118b) has around 23 tooth positions preserved ( Fig. 6b View Fig ). When preserved the teeth are small, slender and monocuspid ( Fig. 6a View Fig ). Te sulcus Meckeli is fully closed and fused, and the dentaries are “tubeshaped” ( Fig. 6a–c View Fig ).

Trunk vertebra: UM-BFI 3195 is small and lightly build ( Fig. 6g –k View Fig ). Te centrum is procoelous, with a small cotyle and condyle flattened dorsoventrally ( Fig. 6g, h, j View Fig ). Te condyle is not inclined in lateral view ( Fig. 6k View Fig ). Te prezygapophyses are small and strongly oriented dorsomedially ( Fig. 6a, i View Fig ). Te neural crest is broken but does not seem to extend past the postzygapophyses ( Fig. 6i, k View Fig ). Te subcentral margins are barely visible, and a pair of subcentral foramina are present on the ventral surface of the centrum ( Fig. 6j View Fig ).

Sacral vertebra: UM-BFI 3193 is small and lightly build ( Fig. 6l–p View Fig ). Te centrum is amphicoelous, with the notochordal canal opened ( Fig. 6l, m View Fig ). Te vertebra is very damaged, but the ventral view shows the fusion between two vertebrae ( Fig. 6o View Fig ). Te pleurapophyses are poorly preserved, but their orientation shows their meet distally ( Fig. 6o, p View Fig ).

Attribution and remarks. Te dentition and closure of the sulcus Meckeli are diagnostic for dentaries of Gekkota in Europe ( Augé, 2005; Čerňanský et al., 2023a; Daza et al., 2014). In the Quercy Phosphorites two genera have been recognized, i.e., Bauersaurus Čerňanský et al., 2023a, known exclusively from the early Eocene (MP 10–11) locality of Cos, and the younger, relatively more widespread, Cadurcogekko ( Augé, 2005; Čerňanský et al., 2023a; Daza et al., 2014; Georgalis et al., 2021a). Unfortunately, no differences between the two genera are known on their dentaries (the diagnosis of Bauersaurus is based on the maxilla; see Čerňanský et al., 2023a). Besides, outside Quercy, five other genera of gekkotans have also been established from the Eocene of Europe: Dollogekko Čerňanský et al., 2022 , from the early Eocene of Belgium ( Čerňanský et al., 2022), Laonogekko Augé, 2003 , from the early Eocene of the Paris Basin in France ( Augé, 2003), the amber-embedded Yantarogekko Bauer, Böhme & Weitschat, 2005 , from the early Eocene of the Baltic Sea region (Bauer et al., 2005), Geiseleptes Villa et al., 2022 , from the early to early middle Eocene of Germany ( Villa et al., 2022), and Rhodanogekko Hoffstetter, 1946 , from the middle Eocene of France ( Hoffstetter, 1946). Tus, we tentatively assign all our specimens to Gekkota indet.

UM-BFI 3193 is assigned to Gekkota on the basis of an amphicoelous condition (known, among squamates, only in Gekkota in the Cenozoic of Europe; Augé, 2005; Čerňanský et al., 2018; Daza et al., 2014; Delfino et al., 2011; Estes, 1983). Amphicoelous vertebrae have in the past been assigned to Cadurcogekko ( Augé, 2005; Rage, 1988) but this assignment is not fully confirmed, because no articulated specimens of this genus are known.

UM-BFI 3195 is more puzzling. It does matches the general morphology of known Cenozoic gekkotans from Europe ( Daza et al., 2014) but differs in being procoelous. Procoelous vertebrae are known in certain extant gekkotan taxa ( Hoffstetter & Gasc, 1969) but have never been documented in the Cenozoic fossil record in Europe ( Daza et al., 2014). Te presence of both amphicoelous and procoelous vertebral material assigned to Gekkota indicates that at least two species of gekkotans were present in La Bouffie. It also marks the first occurrence of a procoelous gekkotan in the Cenozoic fossil record of Europe.