Fossil lizards from the locality of Gannat (late Oligocene–early Miocene, France) and a revision of the genus Pseudeumeces (Squamata, Lacertidae)

Abstract

Pseudeumeces is a distinct lacertid lizard that is known from one species, P. cadurcensis (Filhol). Two species, Ligerosaurus pouiti and "Pseudeumeces" walbeckensis, previously referred to Pseudeumeces, do not belong to this genus. Pseudeumeces cadurcensis is characterized by a heterodont dentition, including large, posterior, crushing teeth on both the maxilla and dentary. Pseudeumeces differs from the Oligocene lacertid lizards Lacerta s.l. filholi and Mediolacerta that have non-expanded, bi-or tricuspid teeth. Dracaenosaurus, an Oligocene lacertid lizard, also possesses crushing, posterior teeth, but its teeth and jaw are much heavier than in those of Pseudeumeces. New specimens from Gannat document cranial elements previously unknown, i.e. frontal and parietal. Pseudeumeces is known with certainty from the early Oligocene (MP25) to the early Miocene (MN1). Notable features of Pseudeumeces (firm lateral contact between the coronoid and the dentary; strongly curved mandibule; tooth morphology and tooth number reduction) corroborate the previous assumption that this lacertid lizard was probably durophagous. Four Oligocene European lacertid lizards form a morphological and chronological series, but the common ancestry of these species has not been definitively proved.

The new rare record of the late Oligocene lizards and amphisbaenians from Germany and its impact on our knowledge of the European terminal Palaeogene

“…If the length of the preserved part is 7.4 mm, it may be estimated that the whole element was was between 9 and 10 mm long. The frontal is nearly identical to the frontal RH-B2-775 from Gannat, described as Pseudeumeces cadurcensis by Augé and Hervet (2009, fig. 4).…”

Fossil lizard from central Europe resolves the origin of large body size and herbivory in giant Canary Island lacertids

“…More recently, the Palaeogene date of the split was confirmed (Hipsley, Miles & Müller, ). Insofar as Pseudeumeces cadurcensis , which first occurs in MP 25 (Augé & Hervet, ), documents the divergence of Gallotia and Psammodromus already by ∼28 Mya, the divergence of Gallotiinae and Lacertinae was likely to have taken place considerably earlier. The oldest Canary Islands are Fuerteventura and Lanzarote, in the east, with subaerial rocks being dated to 20.4–20.6 Myr (Coello et al ., ).…”

“…Very similar to Pseudeumeces cadurcensis but distinguished from it by the following characters: larger size; less ventrally convex dentary; angular process of dentary reduced, not reaching level of the coronoid apex; ratio of anterior and posterior region of frontal 3 : 4, rather than 1 : 2; stronger ornamentation; interparietal scute smaller and narrower than large occipital scute (in P. cadurcensis , the interparietal is large; see Augé & Hervet, ). Distinguished from extant gallotiine lizards by the presence of amblyodont dentition ( sensu Hoffstetter, ).…”

A phylogeny of open‐habitat lizards (Squamata: Lacertidae: Ophisops) supports the antiquity of Indian grassy biomes

“…Hipsley et al ., , ; http://fossilworks.org/), we only used fossils that have been included in phylogenies. We used exponential priors (mean = 2) for three fossil calibrations: Crown Amphisbaenidae (offset 66 Ma), based on the oldest amphisbaenid fossil, the Palaeocene Chthonophis subterraneus , which is nested within the extant amphisbaenians (Longrich et al ., ); Crown Lacertidae (offset 47.8), Cryptolacerta , originally described as a stem amphisbaenian (Müller et al ., ), the Lutetian Cryptolacerta , clusters with the Lacertidae in a recent comprehensive analysis (Longrich et al ., ); Crown Gallotinae (offset 24.5), based on Dracaenosaurus which clusters with the Gallotinae (Müller et al ., ) and ranges as far back as MP28 (Mertz et al ., ; Augé & Hervet, ). …”