Lacertidae

Lacertidae View in CoL View at ENA ( Figs 11F–O View Figure 11 , 12A, B, Q, R View Figure 12 )

The anterior premaxillary process of the maxilla of lacertids has a deep anterior concavity, because both anteromedial and anterolateral processes are well developed ( Fig. 12Q, R View Figure 12 ). The two processes are similar in size, but the anteromedial one can develop a lappet on its dorsal surface ( Figs 11H–O View Figure 11 , 12A, B, R View Figure 12 ): the lappet is present in all species except Ac. erythrurus ( Figs 11F, G View Figure 11 , 12Q View Figure 12 ), Al. fitzingeri , Al. marchi , E. arguta , H. graeca and Ophisops elegans . Barahona (1996) reported a lappet in juveniles of Lacerta viridis (probably Lacerta bilineata , since her specimens were collected in the Iberian Peninsula), but not in adults and, therefore, at least in this species, this could be a feature linked to ontogenetic variation. However, all adult specimens of Lacerta included in this study present a lappet ( Figs 11H–J View Figure 11 , 12R View Figure 12 ). In lateral view, the posterior process is large and pointed. In I. monticola monticola , Lacerta , Po. bocagei , Po. carbonelli , Po. filfolensis , Po. hispanicus , Po. lilfordi , Po. melisellensis , Po. milensis , Po. muralis , Po. pityusensis , Po. siculus , Po. tauricus , Po. tiliguerta and Po. waglerianus , the dorsal margin of this process presents a step, which develops a posteriorly projecting spur in Lacerta agilis , Po. melisellensis , Po. milensis , Po. tauricus and sometimes also Lacerta bilineata , Lacerta viridis and Po. muralis . The spur is always strongly developed in Po. melisellensis ( Fig. 11K, L View Figure 11 ), but it can be short or even almost absent in Lacerta agilis , Po. milensis and Po. tauricus . Lacerta bilineata , Lacerta viridis and Po. muralis can either display a short spur ( Fig. 11J View Figure 11 ) or a simple step ( Fig. 11H, I View Figure 11 ). The wide vomeronasal foramen opens at the base of the anterior margin of the dorsal process, in an anteriorly directed concavity bordered laterally and medially by two low ridges. The superior dental foramen is wide and is followed by a wide posteriorly directed groove. The tooth row does not reach the posterior end of the bone, leaving a small posterior toothless portion that is shorter in large-sized species. Teeth are cylindrical, pleurodont, slender, mono- and bicuspid [morphotype B and G sensu Kosma (2004), respectively]. Tricuspid teeth [morphotype H sensu Kosma (2004)] can also be present, mostly in large-sized species. Hellenolacerta graeca , Po. filfolensis , Po. lilfordi , Po. melisellensis , Po. milensis , Po. pityusensis , Ti. lepidus and some specimens of Po. tauricus and Lacerta trilineata can have a low number of hypertrophied maxillary teeth ( Figs 11K, L, O View Figure 11 , 13 View Figure 13 ). Hypertrophied teeth are present also on the maxillae of MDHC 48 and 73, two young individuals of Lacerta bilineata . The facial process is roughly subtriangular in shape, with slightly irregular anterior and posterodorsal margins and two projections developing posterodorsally from its dorsal end. The two projections can be narrow ( Ac. erythrurus and Ophisops elegans ; Fig. 11F, G View Figure 11 ) or large (other species; Figs 11H–O View Figure 11 , 12A, B View Figure 12 ) in lateral view and the anterior one is more developed than the posterior one. They are scarcely developed in Al. fitzingeri , Al. marchi , Ar. bedriagae , Z. vivipara ( Fig. 12A, B View Figure 12 ) and in some specimens of Lacerta schreiberi and Ti. lepidus . A well-developed dermal ornamentation is present on the lateral surface of the facial process ( Fig. 11H, J, K, M View Figure 11 ), except for Ac. erythrurus , Algyroides , Da. oxycephala , Di. mosorensis , E. arguta , H. graeca , I. bonnali , I. horvathi , Ophisops elegans and Z. vivipara , in which the ornamentation is absent or less developed ( Figs 11F View Figure 11 , 12A View Figure 12 ). The sulcus between the areas covered by internasal and prefrontal scales can be visible in Lacerta , Ti. lepidus and sometimes Podarcis (e.g. Po. muralis , Po. tauricus and Po. waglerianus ). The medial surface has a low and arched ridge roughly at midlength, starting on the dorsal surface of the palatal shelf and running posterodorsally. The ridge appears to be slightly more developed in Al. nigropunctatus , Ar. bedriagae , H. graeca , Lacerta agilis , Lacerta bilineata ( Fig. 11I View Figure 11 ), Lacerta schreiberi and Z. vivipara ( Fig. 12B View Figure 12 ), and is not visible in Ac. erythrurus ( Fig. 11G View Figure 11 ). In Ophisops elegans and Psammodromus algirus , there is also a low ridge running dorsoventrally from the middle of the anterior margin to the palatal shelf ( Fig. 11N View Figure 11 ). Measurements, number of tooth positions and of ventrolateral foramina are given in the Supporting Information 3.