10.5061/DRYAD.VJ969
Racicot, Rachel A.
Yale University
Rowe, Timothy
The University of Texas at Austin
Data from: Endocranial anatomy of a new fossil porpoise (Odontoceti:
Phocoenidae) from the Pliocene San Diego Formation of California
Dryad
dataset
2014
endocast
Sinus
pterygoid sinus
Semirostrum ceruttii
pterygoid
2014-03-25T16:04:41Z
2014-03-25T16:04:41Z
en
https://doi.org/10.1666/13-109
3130284 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
The Pliocene fossil porpoise SDSNH 65276 has extremely elongate mandibular
morphology, unlike that of any marine amniote, and is superficially most
similar to the living bird species known as skimmers (Rynchops sp.).
Endocasts of the pterygoid sinuses and endocranial cavity were digitally
segmented from high-resolution X-ray CT scans of the specimen to explore
internal anatomy of functionally and phylogenetically important anatomical
features of this specimen and odontocetes in general. The sinuses are
similar in volume and shape to extant porpoise species, but the dorsal
extension of the preorbital lobes are particularly elongate as in the
harbor porpoise (Phocoena phocoena). The cranial endocast also shows
similarities with extant porpoises, but has much deeper interhemispheric
fissures, which are filled by ossified meninges, particularly a deep falx
cerebri and shallower tentorium cerebelli. Ossifications of these parts of
the meninges may reflect faster angular accelerations of the head, deeper
diving ability, or both. Penetrations of the endocranial cavity for
cranial nerves and blood vessels are like those of extant porpoises. The
internal skull morphology of this unique delphinoid sheds additional light
both on its phylogenetic affinities and novel odontocete adaptations.
Supplemental Data 2Three-dimensional PDF of digitally extracted right
pterygoid sinus of the extinct porpoise Semirostrum ceruttii, SDSNH
65276.SUPPLEMENTARY FIGURE 1.pdfSupplemental Data 3Three-dimensional PDF
of digitally extracted left pterygoid sinus of the extinct porpoise
Semirostrum ceruttii, SDSNH 65276.SUPPLEMENTARY FIGURE 2.pdfSupplemental
Data 4Three-dimensional pdf of digitally extracted whole cranial endocast
of the extinct porpoise Semirostrum ceruttii, SDSNH 65276.SUPPLEMENTARY
FIGURE 3.pdfSupplemental Data 1Measurements of the pterygoid sinuses of
the extinct porpoise Semirostrum ceruttii, SDSNH 65276, in mm unless
otherwise indicated.Supplementary Table 1.docx
California