CRANIAL KINESIS OF ANGUIS-FRAGILIS AND EV OLUTION OF PALATE IN LACERTILIA

Flexipalatality and hyperstreptostyly are two alternative trends of im proving of the cranial kinesis in evolution of lizards. The slowworm A nguis fragilis has the amphikinetic skull with intermediate streptosty ly and flexipalatality. Its extremely long anterior (palatal) processe s of pterogoids are flexible ventral of the posterior edges of palatin es. Flexipalatality evolved independently in different groups of lizar ds. However, various types of flexipalatality in existing lizards form the morpho-functional row illustrating successive stages of evolution of palate flexibility (1-Anguis fragilis, 2-Varanidae, 3-Scincidae an d Cordylidae, 4-Gekkota). Evolution of flexipalatality includes paedom orphosis-retrogenesis (fetalization), but is not restricted to them.