Lacertidae, Oppel, 1811

Published, First, 2007, Systematics of the Palaearctic and Oriental lizard tribe Lacertini (Squamata: Lacertidae: Lacertinae), with descriptions of eight new genera, Zootaxa 1430, pp. 1-86 : 66

History of Lacertidae

The history of lacertid lizards has been discussed elsewhere ( Arnold 1989a, 2004; Carranza et al. 2004). The Lacertidae are probably an essentially west Palaearctic group that was originally confined to Europe and perhaps adjoining areas to the southwest. The family has a long fossil history in Europe extending back at least to the Lower Eocene, about 50 My ago. Amber-preserved material of Succinilacerta from the mid- Eocene already show the distinctive head and body scaling found in modern lacertids ( Borsuk-Bialynicka et al. 1999; Böhme & Weitschat 1998, 2002). Parsimony suggests that two of the three extant main groups of lacertids are European in origin, namely the Gallotiinae and the Lacertini ( Fig. 26). A molecular clock based on mitochondrial DNA sequences (see Fig. 2 and Appendix I) indicates that separation of the Gallotiinae and Lacertinae perhaps occurred around 20 My ago, in the early Miocene, although albumin immunology suggests it was earlier, about 30–35 My ago in the later Oligocene ( Mayer & Benyr 1994). Phylogeny indicates that the Eremiadini separated from the Lacertini at a later date. As already noted, there are few or no features of the three main groups of lacertids that are likely to be usually preserved in fossils, so these are unlikely to help date separations.

If Europe is the source area for modern lacertids, there must have been several invasions of other regions. If the Gallotiinae are European in origin, the age of the deepest dichotomies within Gallotia suggest its ancestor invaded the Canary Islands from there over 12 My ago ( Fig. 2). This movement must have been wholly or partly transmarine. It could have occurred via northwest Africa but there is no direct evidence for this. Given the pattern of oceanic currents in the Atlantic, invasion may possibly have been direct from western Europe. Northwest Africa was invaded by members of the Psammodromus hispanicus group, to produce P. blanci and P. microdactylus . A molecular clock ( Carranza et al. 2006) suggests this movement may also have been transmarine, as it appears to have occurred long before the contact of Europe and Northwest Africa at the Strait of Gibraltar in the Messinian, 5.6 My ago. Psammodromus algirus also invaded Northwest Africa across water, but at a much later date, perhaps around 2 My ago ( Carranza et al. 2006). A further likely spread from the European region into Africa was of the Eremiadini , which is considered in the next section.