Absence of Suction Feeding Ichthyosaurs and Its Implications for   Triassic Mesopelagic Paleoecology

doi:10.1371/journal.pone.0066075

CORC > 北京大学 > 地球与空间科学学院

	Absence of Suction Feeding Ichthyosaurs and Its Implications for Triassic Mesopelagic Paleoecology
	Motani, Ryosuke ; Ji, Cheng ; Tomita, Taketeru ; Kelley, Neil ; Maxwell, Erin ; Jiang, Da-yong ; Sander, Martin
刊名	plos one
	2013
关键词	AQUATIC PREY CAPTURE HYOID APPARATUS DEEP-SEA ESCHRICHTIUS-ROBUSTUS FUNCTIONAL-MORPHOLOGY BEAKED-WHALES GIANT-SQUID GRAY WHALE KINEMATICS EVOLUTION
DOI	10.1371/journal.pone.0066075
英文摘要	Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were 'ram-feeders', without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the establishment of modern-style mesopelagic animal communities in the Triassic. This new interpretation matches the fossil record of coleoids, which indicates the absence of soft-bodied deepwater species in the Triassic.; Multidisciplinary Sciences; SCI(E); PubMed; 8; ARTICLE; 12; e66075; 8
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/190086]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Motani, Ryosuke,Ji, Cheng,Tomita, Taketeru,et al. Absence of Suction Feeding Ichthyosaurs and Its Implications for Triassic Mesopelagic Paleoecology[J]. plos one,2013.
APA	Motani, Ryosuke.,Ji, Cheng.,Tomita, Taketeru.,Kelley, Neil.,Maxwell, Erin.,...&Sander, Martin.(2013).Absence of Suction Feeding Ichthyosaurs and Its Implications for Triassic Mesopelagic Paleoecology.plos one.
MLA	Motani, Ryosuke,et al."Absence of Suction Feeding Ichthyosaurs and Its Implications for Triassic Mesopelagic Paleoecology".plos one (2013).