New genus of diminutive microhylid frogs from Papua New Guinea

Fred Kraus
2010 ZooKeys  
A new genus of diminutive (10.1-11.3 mm) microhylid frogs is described from New Guinea that is unique in its combination of having only seven presacral vertebrae, a reduced phalangeal formula that leaves the fi rst fi ngers and fi rst toes as vestigial nubs, and reduction of the prepollex and prehallux to single elements. Relationships to other genera are unknown, but overall similarity suggests some relationship to Cophixalus, although that genus also diff ers in some muscle characters and
more » ... characters and likely remains paraphyletic. Th e new genus contains two species, which are among the smallest known frogs in the world. Th eir miniaturization may be related to their inhabiting leaf litter, exploitation of which may select for small size. Th e new genus is currently known only from one mountaintop in the southeasternmost portion of New Guinea and another on a nearby island. Th is region is part of the East Papuan Composite Terrane and, should this lineage prove endemic to that region, it may suggest that it originated prior to that geological unit's docking with mainland New Guinea at 23-29 MY.
doi:10.3897/zookeys.48.446 fatcat:wmqmhep6wrhprejwr7aftybwre