Lacerta Linnaeus, 1758

Tschopp, Emanuel, Villa, Andrea, Camaiti, Marco, Ferro, Letizia, Tuveri, Caterinella, Rook, Lorenzo, Arca, Marisa & Delfino, Massimo, 2018, The first fossils of Timon (Squamata: Lacertinae) from Sardinia (Italy) and potential causes for its local extinction in the Pleistocene, Zoological Journal of the Linnean Society 184 (3), pp. 825-856 : 825-826

Lacerta Linnaeus, 1758 and thus all species currently referred to Timon were initially proposed as species of Lacerta . Only in 1996, was Timon recognized as a distinct genus ( Mayer & Bischoff, 1996), a conclusion that has since been widely accepted ( Fu, Murphy & Darevsky, 1997; Harris, Arnold & Thomas, 1998; Fu, 1998, 2000; Harris & Carretero, 2003; Arnold, Arribas & Carranza, 2007; Schmidtler, 2010; Pyron, Burbrink & Wiens, 2013; Ahmadzadeh et al., 2016).

Six species are currently attributed to Timon : T. kurdistanicus ( Suchov, 1936) , T. lepidus ( Daudin, 1802) , T. nevadensis ( Buchholz, 1963) , T. pater ( Lataste, 1880) , T. princeps ( Blanford, 1874) and T. tangitanus ( Boulenger, 1881) ( Ahmadzadeh et al., 2012, 2016; Miraldo et al., 2013). Molecular and morphological phylogenetic analyses show that Timon is the sistergenus to Lacerta (e.g. Carranza, Arnold & Amat, 2004; Arnold et al., 2007; Kapli et al., 2011; Pyron et al., 2013; Sagonas et al., 2014; Mendes et al., 2016), and that it includes three distinct clades, which are also geographically segregated: T. lepidus and T. nevadensis occur on the European side of the western Mediterranean basin; T. pater and T. tangitanus inhabit the North-African coast of the western Mediterranean basin; and T. kurdistanicus and T. princeps are distributed in the Middle East, with no connection to the Mediterranean ( Ahmadzadeh et al., 2016). The divergence of the two distinct eastern and western genetic lineages of Timon , and the split between the European and African subclades, were estimated at 14.46 Mya and approximately 7.42 Mya, respectively, whereas the evolutionary divergence between Lacerta and Timon dates back to approximately 18.6 Mya ( Ahmadzadeh et al., 2016).

The vast majority of fossil remains reported in the literature were recovered from geographical areas where Timon still exists today ( Mateo, 2009). FosFARbase lists 34 fossil occurrences referable to Timon , from the Gelasian to the Holocene, and from France, Spain, Portugal and Gibraltar ( Böhme & Ilg, 2003). Some additional occurrences are reported by other authors, still from Quaternary localities of France and Spain (e.g. Fernández Eraso et al., 2010; Bañuls Cardona et al., 2012; Benítez de Lugo Enrich et al., 2015). The oldest fossil might be represented by a dentary from the Pliocene of France, which constitutes the holotype of Lacerta ruscinensis Depéret, 1890 , but was considered closely related to Timon lepidus by Depéret (1890) himself, Młynarski (1956) and Estes (1983). Estes (1983) even suggested that the specimen might be referred to the extant species, resulting in L. ruscinensis being a junior synonym of T. lepidus . The absence of records from Northern Africa and the Middle East is most probably due to the very scarce knowledge of the palaeoherpetofaunas from those regions.

Reports of fossils outside the current distribution are rare, and none of them has been described or properly identified. A possible Timon specimen from the late Pleistocene of Germany ( Brunner, 1957) was referred to Lacerta sp. by Estes (1983), and to L. agilis by Mateo (1988). Large-sized, lacertid bones from Gargano ( Italy) have been referred to Lacerta sp. by Delfino & Bailon (2000), who also mention similarities with Timon lepidus . Bailon (2004) figured and described a mandible from the Middle Pleistocene of Corsica with affinities to Timon lepidus . Both the occurrences from Gargano and Corsica have been included in a distribution map of the genus Timon by Ahmadzadeh et al. (2016), which indicates additional fossil occurrences in Sicily ( Italy) and on Malta. These fossils from Sicily and Malta most probably represent the findings of the extinct ‘ Lacerta ’ siculimelitensis by Böhme & Zammit-Maempel (1982), although this is not explicitly stated. This enigmatic large-sized lacertid was considered to belong to Timon by Mateo (2009), but a detailed reassessment of the species would be needed to confirm this interpretation.

In order to improve knowledge of the insular lizards that could be related to Timon , herein we describe and analyse the relationships of fossil material from the Calabrian to Upper Pleistocene fissure fillings of Monte Tuttavista (Orosei, Sardinia, Italy), which was initially referred to Lacerta sp. on the basis of large size ( Abbazzi et al., 2004), but whose morphology was not described in detail.

INSTITUTIONAL ABBREVIATIONS

The material from Monte Tuttavista was initially numbered using ‘MT’ as abbreviation for the locality, ‘VIa’ for specimens from the site ‘Cava VI-antica’, ‘IX’ for the site ‘Cava IX- Prolagus ’ and ‘BS’ for the site ‘Cava VIII-Blocco Strada’. This resulted in specimen numbers such as ‘MT-IX-054’. All these specimens are deposited in the Soprintendenza Archeologia, Belle Arti e Paesaggio per le province di Sassari e Nuoro, Nuoro, Italy.

Other institutional abbreviations used herein are the following: CIPA, Osteoteca, LaboratorioArqueociencias, Lisbon, Portugal ; COMGR, Collezione Osteologica Mauro Grano, Roma, Italy ; HUJ-OST, Osteological Collections, Hebrew University of Jerusalem, Israel ; MDHC, Massimo Delfino Herpetological Collection in the Museum of Geology and Paleontology of the Department of Earth Sciences of the University of Turin, Italy ; MNCN, Museo Nacional de Ciencias Naturales , Madrid, Spain ; MNHN, Muséum National d’Histoire Naturelle, Paris, France ; MRAC, Musée Royal de l’Afrique Centrale , Tervuren, Belgium ; NHMUK, Natural History Museum, London, UK ; NHMW, Naturhistorisches Museum Wien, Vienna, Austria ; PIMUZ, Paläontologisches Institut und Museum der Universität Zürich, Switzerland ; SRK, Sammlung Ralf Kosma, Staatliches Naturhistorisches Museum Braunschweig, Germany ; UAM, Universitad Autónoma de Madrid, Spain ; ZZSiD, Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Krakow, Poland .