Distribution and geographic variation of the Ameivas of Puerto Rico and the Virgin Islands

The broad outlines of the taxonomy and distribution of the Antillean ameivas have been sketched by BARBOUR & NOBLE (1915). Two principal ancestral stocks were recognized: (1) One gave rise to the Ameiva ameiva group whose center of origin and dispersal was northeastern South America, and which extended westward into Central America and also up the Lesser Antilles to Puerto Rico and Hispaniola.¹ (2) The other gave rise to the Ameiva undulata group which originated in and dispersed from Central America, moving into northwestern South America and into the Greater Antilles as far eastward as Hispaniola. In addition to these two main stocks, they postulated still a third origin for a small group of species in the Bahamas – Puerto Rico – St. Croix area (A. maynardi, A. wetmorei and A. polops), but which they allied more closely to the A. undulata than to the A. ameiva group. A final, somewhat problematic group consists of the South American Ameiva bifrontata and its subspecies. They postulated that it either arose from the Ameiva ameiva group or from still a fourth stock. Accordingly to BARBOUR & NOBLE’S view, then, the Antilles comprise two main groups which have invaded the area from opposite directions and which overlap on Hispaniola (or from Hispaniola to St. Croix if Ameiva wetmorei and A. polops are considered allied to the A. undulata group – see below).