Press to Close

PLAIN- LANGUAGE SUMMARY

A skull of an Anolis lizard preserved in 15-20 million-year-old amber from the Dominican Republic was examined using high-resolution X-ray computed tomography (CT). Images generated from these data demonstrate the lack of a splenial bone in the lower jaw and allow evaluation of skull breakage. The skull and remaining soft tissue differ in detail from two other amber-preserved anoles from the same geological setting. All three may be closely allied with modern species such as A. chlorocyanus, but they are distinct from other living anoles of Hispaniola grouped as twig dwarf anoles. The pattern of breakage and missing bones suggests avian predation, with trauma inflicted on the posterior portion of the skull, followed by partial decomposition and loss of some of the snout bones prior to complete entombment in resin. Geological evidence may indicate that the origin of the Greater Antillean islands now emergent was no earlier than 35 million years. Thus, judging from the anatomy and variability of the small sample of anoles preserved in amber, compared to patterns in modern anoles, the evolutionary strategy of ecological diversification in Caribbean anoles was established between 35 and 20 million years ago.