Cranial and endocranial anatomy of a three-dimensionally preserved teleosauroid thalattosuchian skull.

Autor: Wilberg EW; Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York, USA., Beyl AR; Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York, USA., Pierce SE; Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA., Turner AH; Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York, USA.
Jazyk: angličtina
Zdroj: Anatomical record (Hoboken, N.J. : 2007) [Anat Rec (Hoboken)] 2022 Oct; Vol. 305 (10), pp. 2620-2653. Date of Electronic Publication: 2021 Jul 14.
DOI: 10.1002/ar.24704
Abstrakt: Thalattosuchians represent one of the several independent transitions into the marine realm among crocodylomorphs. The extent of their aquatic adaptations ranges from the semiaquatic teleosauroids, superficially resembling extant gharials, to the almost cetacean-like pelagic metriorhynchids. Understanding the suite of osteological, physiological, and sensory changes that accompanied this major transition has received increased attention, but is somewhat hindered by a dearth of complete three-dimensionally preserved crania. Here, we describe the cranial and endocranial anatomy of a well-preserved three-dimensional specimen of Macrospondylus bollensis from the Toarcian of Yorkshire, UK. The trigeminal fossa contains two similar-sized openings separated by a thin lamina of prootic, a configuration that appears unique to a subset of teleosauroids. Macrospondylus bollensis resembles other thalattosuchians in having pyramidal semicircular canals with elongate cochlear ducts, enlarged carotid canals leading to an enlarged pituitary fossa, enlarged orbital arteries, enlarged endocranial venous sinuses, reduced pharyngotympanic sinuses, and a relatively straight brain with a hemispherical cerebral expansion. We describe for the first time the olfactory region and paranasal sinuses of a teleosauroid. A relatively large olfactory region suggests greater capacity for airborne olfaction in teleosauroids than in the more aquatically adapted metriorhynchoids. Additionally, slight swellings in the olfactory region suggest the presence of small salt glands of lower secretory capacity than those of metriorhynchoids. The presence of osteological correlates for salt glands in a teleosauroid corroborates previous hypotheses that these glands originated in the common ancestor of Thalattosuchia, facilitating their rapid radiation into the marine realm.
(© 2021 American Association for Anatomy.)
Databáze: MEDLINE
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