Our analysis of parts of the mitochondrial ribosomal 12S and 16S genes from
39 populations of Southeast Asian ranid frogs confirms that the fanged fro
gs are a monophyletic clade. This group, properly called Lim-nonectes, appe
ars to have arisen in the early Tertiary at a time when free faunal exchang
e was possible among Southeast Asia, Borneo, Sumatra, Java, and, probably,
Sulawesi, Pour species groups are tentatively identified within the clade.
Part of group 1 includes species related to L. kuhlii that occur in Borneo.
Another part of group 1 includes species from Malay Peninsula and Thailand
that are related to L. pileata. Species group 2, L. leporina, occurs only
in Borneo. Species group 3 is restricted to species distributed in Sulawesi
and the Philippines. Species group 4 includes L. blythii and relatives. Th
ere is a lack of compatibility between phylogenetic hypotheses generated fr
om molecular and morphological data sets. These differences are related, in
large part, to whether some species of Limnonectes have secondarily lost f
angs or whether lack of fangs represents the primitive condition. (C) 2000
Academic Press.