Data from: Palaeobiogeography of the north pacific toothed mysticetes (Cetacea, Aetiocetidae): a key to Oligocene cetacean distributional patterns

Biogeographical distributional patterns of cetaceans reflect dispersal
events and colonization of the oceans from their ancestral area in the
ancient Sea of Tethys ~53 Ma. Likewise, they shows several vicariance
events throughout the evolutionary history of this group. However, our
understanding of how these processes took place and what biogeographical
scenarios occurred among the different groups of cetaceans through time,
is limited. Consequently, this work focuses on explaining the
distributional patterns of the well-known North Pacific toothed
mysticetes, Aetiocetidae, through the power of retrodiction offered by
track analysis (panbiogeography) and cladistic biogeography, using the
approach of evolutionary biogeography. Our results show that the
distributional patterns of Aetiocetidae explain their endemism in the
North Pacific, as well as indicate that their hypothetical ancestor
probably colonized the Pacific from the Atlantic Ocean by a dispersal
event (founder effect) via the Central American Seaway. Furthermore, their
biogeographic history shows the adaptive radiation (cladogenesis) of
Aetiocetidae as result of peripatric speciation followed by sympatric
speciation within a heterogeneous environment. Finally, the biogeographic
framework of Aetiocetidae further supports the relevant role that the
Pacific Ocean has played in the evolution of Oligocene cetaceans as a
geographic area that promoted endemism, dispersal, and colonization. While
at more local scales, environmental conditions further promoted increased
diversity and disparity amongst Mysticeti.