Problematic early oligocene toothed whale (cetacea, ?Mysticeti) from Waikari, North Canterbury, New Zealand

Abstract

An incomplete whale mandible from the Amuri Limestone (Globigerina angiporoides Zone, lower Whaingaroan Stage; Early Oligocene), Waikari,New Zealand, has relatively large heterodont cheek-teeth with rather delicate denticles and a relatively small but inflated ramus. It is more derived in these features than typical Archaeoceti, and probably represents a primitive species of Mysticeti (baleen whales and relatives). No such specimen has been described previously, but because it cannot be positively diagnosed by synapomorphies at or below subordinal level, it is not formally named as a new species. Such incomplete fossils might be described more often even if not formally named, because, despite their lack of synapomorphies diagnostic of low taxonomic rank, they may have important implications for stratigraphy, paleobiogeography, and related aspects of paleobiology. © Crown 1989.