Notes on the systematic value of the tongue morphology in different genera and species groups of lacertid lizards (Reptilia: Lacertidae)

Abstract

The tongue shape and its epidermal structure was examined in a stock of palearctic and paleotropical lizards from Europe, Africa, the Middle East and south eastern Asia. The results of this preliminary report clearly point out the systematic importance of this morphological feature in providing valuable generic and specific characters. The fundamental pattern described for the genera <i>Podarcis, Lacerta</i> sensu stricto and <i>Gallotia</i>, e. g., is very distinctive despite several features in common, likely due to ancient phyletic relationships. A number of similar morphological trends stress the reciprocal affinities between <i>Lacerta (Archaeolacerta)</i> and the widely spread genus <i>Podarcis</i> which is still undergoing speciation. Another case is the minor but significant affinities linking the genera <i>Lacerta</i> sensu stricto and <i>Gallotia</i>, the latter also undergoing more complicated speciation due to its insular isolation. The interspecific differences in the taxa belonging to the so-called “species groups” such as <i>Podarcis</i>, are scanty or insignificant. Instead there are striking differences in the generic patterns of the tongue morphology in Afro-Asian lacertid lizards. However, a similar pattern was found in the African genera <i>Adolfus</i> and <i>Holaspis</i> or Centromastix (= <i>Gastropholis</i> according to Arnold, 1989) and <i>Ichnotropis</i>.