Data from: Nasal compartmentalization in Kogiidae (Cetacea, Physeteroidea): Insights from a new late Miocene dwarf sperm whale from the Pisco Formation

Facial compartmentalization in the skull of extant pygmy whales (Kogiidae)
is a unique feature among cetaceans that allows the housing of a wide
array of organs responsible for echolocation. Recent fossil findings
depict a remarkable disparity of the facial bone organization in Miocene
kogiids, but the significance of such a rearrangement for the evolution of
the clade has been barely explored. Here we describe Kogia
danomurai sp. nov., a late Miocene (ca. 5.8 Ma) taxon from the
Pisco Formation (Peru), based on a partially preserved skull with a new
facial bone pattern. Our phylogenetic analysis recovers K.
danomurai as the most basal representative of the extant
genus Kogia, displaying a combination of derived (incipiently
developed and excavated sagittal facial crest) and plesiomorphic features
(high position of the temporal fossa and antorbital notch not transformed
into a narrow slit). Furthermore, when compared with the
extant Kogia, the facial patterning found in K.
danomurai indicates differential development among the facial
organs, implying different capabilities of sound production relative to
extant Kogia spp. Different facial bone patterns are
particularly notable within the multi-species kogiid assemblage of the
Pisco Formation, which suggests causal connections between different
patterns and feeding ecologies (e.g., nekton piscivory and benthic
foraging). At about 5.8 Ma, K. danomurai was part of a
cetacean community composed by clades typical of the late Miocene as well
as other early representatives of extant taxa, a mixture probably
depicting the initial faunal change toward the coastal ecosystem dynamics
of the present-day Southeastern Pacific.