A NEW TROODONTID (DINOSAURIA, THEROPODA) BRAINCASE FROM THE DINOSAUR PARK FORMATION (CAMPANIAN) OF ALBERTA

IVPP-IR > 古低等脊椎动物研究室

	A NEW TROODONTID (DINOSAURIA, THEROPODA) BRAINCASE FROM THE DINOSAUR PARK FORMATION (CAMPANIAN) OF ALBERTA
	CURRIE, PJ; ZHAO, XJ
	1993-10-01
发表期刊	CANADIAN JOURNAL OF EARTH SCIENCES
卷号	30 期号:10-11 页码:2231-2247
文章类型	Article
摘要	A new, well-preserved specimen of Troodon formosus is the first to reveal the internal anatomy of the lower part of the braincase. In addition to providing new information on the brain of this highly encephalized dinosaur, the uncrushed bones clear up anatomical details left obscure by earlier studies. Computerized tomography (CT) scans reveal the nature of the inner ear and the course of the pneumatic ducts diverging from the middle ear. Evidence is presented to show that four of the five periotic pneumatic systems found in bird skulls are present in Troodon. The anterior tympanic recess is the most elaborate system, and diverticula from each side extend anteriorly, dorsally and, posteriorly from the middle ear. The posterior tympanic recess is located within the paroccipital process and the basioccipital, but the pneumatopore posterolateral to the stapedial recess is secondarily closed. The dorsal periotic sinus is represented by a smooth-surfaced concavity on the lateral surface of the prootic. The position of a pneumatic recess in this region is demonstrated by the presence of a pneumatopore in the quadrate. Diverticula from the anterior and posterior tympanic recesses are connected within braincase bones, and a possible pneumatopore in the prootic may connect these to the dorsal tympanic recess. The pneumatic condition of the troodontid articular is unknown. Contralateral connections of the sinus systems have been used to argue for a close relationship between birds and crocodiles, but their presence in this specimen suggests that they appeared more than once in archosaurs or that they are plesiomorphic for crocodiles, dinosaurs, and birds. Cranial pneumaticity cannot be used by itself to resolve the interrelationships of crocodiles, theropods, and birds, but other characters suggest derivation of birds from theropods.
WOS标题词	Science & Technology ; Physical Sciences
关键词[WOS]	CRANIAL ANATOMY ; BIRDS ; ORIGIN
收录类别	SCI
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:A1993MW47200021
引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.205/handle/311034/7585
专题	古低等脊椎动物研究室
作者单位	ACAD SINICA, INST VERTEBRATE PALEONTOL & PALEOANTHROPOL, BEIJING 100044, PEOPLES R CHINA
推荐引用方式 GB/T 7714	CURRIE, PJ,ZHAO, XJ. A NEW TROODONTID (DINOSAURIA, THEROPODA) BRAINCASE FROM THE DINOSAUR PARK FORMATION (CAMPANIAN) OF ALBERTA[J]. CANADIAN JOURNAL OF EARTH SCIENCES,1993,30(10-11):2231-2247.
APA	CURRIE, PJ,&ZHAO, XJ.(1993).A NEW TROODONTID (DINOSAURIA, THEROPODA) BRAINCASE FROM THE DINOSAUR PARK FORMATION (CAMPANIAN) OF ALBERTA.CANADIAN JOURNAL OF EARTH SCIENCES,30(10-11),2231-2247.
MLA	CURRIE, PJ,et al."A NEW TROODONTID (DINOSAURIA, THEROPODA) BRAINCASE FROM THE DINOSAUR PARK FORMATION (CAMPANIAN) OF ALBERTA".CANADIAN JOURNAL OF EARTH SCIENCES 30.10-11(1993):2231-2247.