Lacertini, 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 : 68

History of Lacertini

The molecular clock used here indicates that the Lacertini split into most of its component living genera 12–16 My ago, so they underwent quite rapid speciation at this time. Most genera in the Lacertini have largely allopatric and often disjunct ranges, which may mean that initial spread of the group was followed or accompanied by multiple vicariance (see Fig. 25). A few units do not fit this pattern and have large ranges that overlap with several other taxa, although these too may have began as vicariant isolates with small ranges and then spread. They are Lacerta-Timon ( Fig. 25d), Algyroides ( Fig. 25e) and Podarcis ( Fig. 25f).

The substantial differences in mitochondrial DNA sequences between Lacerta and the two parts of Timon suggest this unit underwent early divergence and spread. The species of Lacerta-Timon have far larger bodysizes than other Lacertini and adults often eat larger prey, so contact with these smaller forms may not have affected these deleteriously, permitting long-term coexistence without strong competition. Certainly, fossils indicate large-bodied lacertids have a long history in Europe ( Estes 1983; Bailón 2004), although it is rarely certain that they belong to the Lacerta-Timon clade. Algyroides also has a relatively wide range, and a distinctive niche being often found in cool wooded situations but, unlike Lacerta-Timon, its range is now disjunct and the total area it covers is small.

Podarcis , like Lacerta-Timon has a very large subcontinuous range, but in contrast to these lizards it appears to impinge on other small-bodied taxa with which it is in contact, there often being evidence of competition. Podarcis may have been responsible for restricting other small-bodied lacertid genera, including Algyroides , Iberolacerta , Archaeolacerta , Dinarolacerta , Dalmatolacerta and Hellenolacerta ( Arnold 1981, 2004; Carranza et al. 2004). Although Podarcis is an old group that diverged around 9 My ago and spread widely in Europe and mesic northwest Africa, it has not penetrated far to the east. Here it reaches only northwest Asiatic Turkey and has an essentially parapatric distribution with Anatololacerta among the islands of the Aegean Sea.

Lacertini have made several incursions outside their original mainly European distribution. The ancestor of Takydromus reached East Asia and diversified there ( Fig. 25c), the cytochrome b and 12S rRNA sequences of mitochondrial DNA used here suggesting that divergence began at least 10 My ago (see Fig. 2). Ota et al. (2002) also showed that genetic divergence within Takydromus is very high, with values up to 20% for combined 12SrRNA and 16SrRNA gene fragments. There is no certain fossil record of this genus, but the poorly known Miolacerta Roček, 1984 of the mid-Miocene of central Europe shows some resemblance ( Arnold 1997). Spread from Europe to the Far East has also occurred in the ancestor of the salamandrid genus Tylototriton (Titus & Larson 1995; Carranza & Arnold 2004; Carranza & Wade 2004), and in that of Cynops , Pachytriton and Paramesotriton (Weisrock et al. 2005) . Molecular divergence within these groups also suggests invasion of the Far East was a long time ago.

Scelarcis may possibly have reached Northwest Africa soon after the main divergence of the Lacertini . Teira made the 600–800 km transmarine journey to the Madeira archipelago as much as 12 My ago, arriving first on the oldest island, Porto Santo, moving on to invade Madeira itself and then the neighbouring Desertas and Selvages islands (Jesus et al. 2005). Assuming it was originally in southwest Europe, Timon reached Northwest Africa around the time of the Messinian salinity crisis or somewhat before, perhaps around 8 My ago ( Fig. 2; Paulo 2001). The Podarcis hispanica group might have invaded this region twice: once about the time of the salinity crisis and again more recently ( Harris et al. 2002) or, according to Pinho et al. (2006), just once during the salinity crisis, followed by a recent back-colonization into south Iberia. Finally, Lacerta agilis appears to have spread eastwards into Central Asia ( Fig. 25a), and Zootoca across the whole of Eurasia to the Pacific coast and Sakhalin and Hokkaido islands ( Fig. 25b), perhaps in the Pleistocene (Surget-Groba et al. 2001). In the Mediterranean, some islands may have been invaded by Podarcis during the Messinian salinity crisis, the isolation caused by subsequent rise in sea level being followed by divergence. For example in the Balearics, P. lilfordi and P. pityusensis split at this time (see Fig. 2) and in the Aegean, the differentiation of P. milensis and P. gaigae from each other and from the mainland P. taurica may have been similar ( Fig. 2; Poulakakis et al. 2005).