. Bulletin of the British Museum (Natural History) Zoology. . Fig. 9 Right clavicles in ventral view, showing variation in medial area. a. strongly expanded, forming continuous loop (Lacerta s. str).; b. strongly expanded, loop interrupted posteriorly (Lacerta s. str.); c. weakly expanded, forming continuous loop ('Lacerta' echinata); d. posterior section completely absent (Holaspis guentheri); e. weakly expanded, forming continuous loop with posterior border thickened (Adolfus vauereselli). 29 Number of short free dorsal ribs. Equal or less than number of long free dorsal ribs (0); More than
. Bulletin of the British Museum (Natural History) Zoology. . Fig. 9 Right clavicles in ventral view, showing variation in medial area. a. strongly expanded, forming continuous loop (Lacerta s. str).; b. strongly expanded, loop interrupted posteriorly (Lacerta s. str.); c. weakly expanded, forming continuous loop ('Lacerta' echinata); d. posterior section completely absent (Holaspis guentheri); e. weakly expanded, forming continuous loop with posterior border thickened (Adolfus vauereselli). 29 Number of short free dorsal ribs. Equal or less than number of long free dorsal ribs (0); More than number of long free dorsal ribs (1). 30 Inscriptional ribs. Often present (0); often absent (1). , , Transverse processes on anterior automatic caudal vertebrae (Fig. 11). Variable within species, in some individuals a long anterior pair of processes more or less at right angles to the vertebra and a shorter parallel posterior pair—pattern B, others lack the posterior pair—pattern A (0,0,0); only anterior pair present in all individuals—pattern A (1,0,0); a long anterior pair and a posterior pair that diverges posteriorly and may sometimes be rather longer— pattern BC (0,1,0); posterior pair diverging posteriorly and always longer than anterior one—pattern C (0,1,1). Etheridge (1967) considered pattern C as the primitive one in lacertids, but it and pattern A are both widespread in lizards as a whole and, if anything, the assumption that pattern A is derived is more parsimonious overall. Among advanced lacertids, the distribution of other characters in compatibility analysis suggests that the C pattern in Acanthodactylus, Mesalina and Ophisops-Cabrita arose directly or indirectly from pattern A (p. 230). An indication that such a change is possible is provided by a specimen of Pedioplanis lineoocel- lata (BMNH ) in which one side of the tail shows the A pattern, like other members of Pedioplanis, while the other exhibits a close approximation to t
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