Abstract
The evolutionary relationships of nine genera of macrotciid lizard (Ameiva, Cnemidophorus, Kentropyx, Dicrodon, Teius, Callopistes, Crocodilurus Tupinambis, and Dracaena are discussed based on an analysis of 25 osteological character states. A phenetic scheme based on the average linkage technique ami an evolutionary sequence diagram arc presented. The result places the nine genera into two groups: A. Ameiva, Cnemidophorus, Kenlropyx, Teius, and Dicrodon; B, Callopistes, Tupinambis, Crocodilurus, and Dracaena. Group B is considered the most derived group of genera; Dracaena being the most derived genus.
An analysis of the fossil record of the macroteiids in association with present distributional patterns suggests thai the ancestors of the macroteiids arose in North America and entered South America at the close of the Mesozoic Era. With the closure of the Panamanian Seaway in Early Pliocene, movement of Ameiva north and Cnemidophorus south, occurred Subsequent geologic activity and contraction of the tropical climate, are responsible for for present distribution of the genera.
