Morphology and systematics of two Miocene alligators from Florida, with a discussion of Alligator biogeography

This paper describes cranial and postcranial remains from Alligator olseni White, 1942 and Alligator of. mefferdi Mock, 1946. An earlier phylogenetic data set has been augmented with new data from these fossils. Although membership in the clade Alligator is generally in accord with previous analyses, neither strict consensus nor Adams consensus trees could resolve placement of all members. Several lines of evidence pertinent to Alligator biogeography are analyzed. Alligator may have dispersed from North America into Asia prior to 15 million years ago, but conclusive evidence is lacking.