A new fossil Anolis lizard in Hispaniolan amber: Ecomorphology and systematics

Abstract

Pre-Pleistocene fossils of Anolis lizards are rare, although 20 Miocene fossils preserved in amber from the island of Hispaniola have been reported on previously. Using light-microscopy and computed-tomography imaging, we studied a new amber fossil Anolis lizard from Hispaniola. The fossil is likely a juvenile and preserves a largely intact left forelimb, including both scales and skeletal elements, as well as some additional skin, skin impressions, and fragmentary skeletal elements from other parts of the body. Using measurements and lamella counts from the forelimb of the fossil and other juvenile anoles, discriminant function analysis and three Euclidean-distance criteria derived from a principal components analysis consistently support classification of the fossil as a member of the trunk ecomorph category, and those results, in combination with two scale characters preserved in the fossil, suggest that it is a member of the Anolis distichus series within the Ctenonotus clade. These results represent only the third case of a well-supported assignment of an Anolis fossil to the trunk ecomorph category and the first to the A. distichus series. They also highlight that such assignments can sometimes be inferred from highly incomplete fossils.