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Composition of the canid auditory bulla and a new look at the evolution of carnivoran entotympanics
- Source :
- Organisms Diversity & Evolution. 19:363-375
- Publication Year :
- 2019
- Publisher :
- Springer Science and Business Media LLC, 2019.
-
Abstract
- The higher carnivoran taxa significantly differ in the morphology of the auditory bulla, but little is known about its non-ectotympanic elements and their contribution to phylogenetically informative bullar characters. The ventral entotympanic sinus, a principal hypotympanic compartment unique to Canidae, expands in post-ossification ontogeny from a distinct portion, rather than the whole, of what is considered the ‘caudal entotympanic’. To trace the earlier development of this sinus and to clarify the potential roles of individual entotympanics in formation of the canid auditory bulla, osteological observations were made on younger skulls of Canis lupus and four additional species. The ventral entotympanic sinus was found to invariably originate at a separate bone provisionally designated the ventral entotympanic. The rest of the caudal entotympanic is a fusion of the posterior (or the proper) caudal entotympanic ossifying near the tympanohyal, and the anterior caudal entotympanic ossifying between the ectotympanic and rostral entotympanic. Examination of the rostral entotympanic also revealed previously unknown details. In sum, the canid auditory bulla includes at least four rather than earlier recognised two (or suspected three) entotympanics. Based on these findings, the composition of the canid intrabullar septum and the homologies of the carnivoran entotympanics are discussed. Within the established phylogenetic framework, the rostral entotympanic and posterior caudal entotympanic appear as plesiomorphic for crown-group Carnivora, while the anterior caudal entotympanic is synapomorphic for Caniformia, and the ventral entotympanic is autapomorphic for Cynoidea. This hypothesis implies that the carnivoran entotympanic patterns may have emerged before complete fusions of bullar bones observed in the fossil record.
- Subjects :
- 0106 biological sciences
0301 basic medicine
Synapomorphy
Autapomorphy
Osteology
Ontogeny
Ectotympanic
Anatomy
Biology
biology.organism_classification
010603 evolutionary biology
01 natural sciences
Caniformia
03 medical and health sciences
030104 developmental biology
Carnivora
Ecology, Evolution, Behavior and Systematics
Bulla (gastropod)
Subjects
Details
- ISSN :
- 16181077 and 14396092
- Volume :
- 19
- Database :
- OpenAIRE
- Journal :
- Organisms Diversity & Evolution
- Accession number :
- edsair.doi...........c24d903947c53f5bfb84d7f61d2f70b5