Two new extinct porpoises—Archaeophocaena teshioensis, gen. et sp. nov., and Miophocaena nishinoi, gen. et sp. nov.—are described from the upper Miocene Koetoi Formation (5.5–6.4 Ma) of Hokkaido, Northern Japan. The…
High-resolution X-ray computed tomographic scans were used to examine pterygoid sinus morphology within extant porpoise species and one delphinid (Tursiops truncatus), in order to consider: 1) intraspecific and interspecific variation…
Longitudinal and cross sections of teeth from 17 species of the Recent dolphins (Delphinoidea and Inioidea) were examined under scanning electron microscope to study the arrangement and ultrastructure of dental…
Toothed whales (crown Odontoceti) are unique among mammals in their ability to echolocate underwater, using specialized tissue structures. The melon, a structure composed of fat and connective tissue, is an…
All extant porpoise species show paedomorphic skeletal traits. These traits are hypothesized to be connected with rapid growth to reproductive size and could thus show geographic variation according to ecological…
The unique pattern of small tubercles on the leading edge of the dorsal fins of harbor porpoises (Phocoena phocoena) has been widely noted in the literature, though their structure or…
All extant members of Phocoenidae (porpoises) have been characterized as pedomorphic based on skeletal characters. To investigate the ontogenetic background for pedomorphosis and assess interspecific differences in ontogeny among phocoenids,…
The existence of at least two biological species of finless porpoises (Neophocaena phocaenoides and N. asiaeorientalis) was accepted only recently. Given the vulnerability of finless porpoises to human activities throughout…
To evaluate and assess the ontogenetic background for paedomorphosis in phocoenids, samples of 144 harbour porpoises, 81 white-beaked dolphins, and 130 Commerson's dolphins were compared in terms of the development…
A new species of phocoenid cetacean Haborophocoena, collected from the Early Pliocene Embetsu Formation, in the close vicinity to the site where the holotype of the type species of the…