| Autor: |
Kirk, E. Christopher, Hoffmann, Simone, Kemp, Addison D., Krause, David W., O'Connor, Patrick M. |
| Zdroj: |
Journal of Vertebrate Paleontology; Nov2014 Supplement, Vol. 34, p203-222, 20p |
| Abstrakt: |
ABSTRACT—Living mammals are distinguished from other extant tetrapods by adaptations for improved senses of hearing, touch, and smell. These adaptations, and concomitant reductions in visual anatomy, evolved during the Mesozoic in the mammalian and therian stem lineages. Here, we present a comparative study of the sensory anatomy of the Late Cretaceous gondwanatherian mammaliaformVintana sertichiin order to draw inferences regarding its sensory abilities and sensory ecology. Our analyses demonstrate thatVintanahas relatively large orbits that may have accommodated large eyes.Vintanaalso possessed cochlear primary and secondary osseous laminae and a cochlear canal that was relatively longer than in non-mammaliaform cynodonts but shorter than in extant therians. These features suggest thatVintanahad some capacity for high-frequency hearing (i.e., >20 kHz), but that its cochlea may have encoded a more limited range of frequencies than the cochleas of most extant therians. The semicircular canals ofVintanahave large radii of curvature and are nearly orthogonal, suggesting high sensitivity to angular head accelerations. These vestibular features may have evolved in order to stabilize large eyes during rapid and/or agile locomotion. Combined with evidence for large olfactory bulbs and a large trigeminal endocast, these data reveal thatVintanapossessed a unique suite of sensory adaptations that distinguish it from other Mesozoic mammaliaforms. If these inferences are correct, thenVintanawas probably a large-eyed and agile species, with a keen sense of smell and better high-frequency hearing than most other Mesozoic mammaliaforms. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
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