Origin of postcranial skeletal pneumaticity in dinosaurs.
نویسنده
چکیده
The sauropodomorph Thecodontosaurus caducus and theropod Coelophysis bauri are the earliest known dinosaurs with postcranial skeletal pneumaticity. In both taxa, postcranial pneumatic features are confined to the cervical vertebrae. This distribution of pneumaticity in the skeleton is most consistent with pneumatization by diverticula of cervical air sacs similar to those of birds. Other hypotheses, including pneumatization by diverticula of the lungs, larynx and trachea, or cranial air spaces, are less well-supported.
منابع مشابه
Vertebral Pneumaticity in the Ornithomimosaur Archaeornithomimus (Dinosauria: Theropoda) Revealed by Computed Tomography Imaging and Reappraisal of Axial Pneumaticity in Ornithomimosauria.
Among extant vertebrates, pneumatization of postcranial bones is unique to birds, with few known exceptions in other groups. Through reduction in bone mass, this feature is thought to benefit flight capacity in modern birds, but its prevalence in non-avian dinosaurs of variable sizes has generated competing hypotheses on the initial adaptive significance of postcranial pneumaticity. To better u...
متن کاملEvolution of archosaurian body plans: skeletal adaptations of an air-sac-based breathing apparatus in birds and other archosaurs.
Living birds represent the only extant sauropsid group in which pulmonary air sacs pneumatize the postcranial skeleton. Notable in this regard is an extraordinary degree of variability, ranging from species that are completely apneumatic to those characterized by air within the entire postcranial skeleton. Although numerous factors (e.g., body size) have been linked with "relative" pneumaticity...
متن کاملPostcranial pneumaticity in dinosaurs and the origin of the avian lung
In birds, diverticula of the lungs and air sacs pneumatize specific regions of the postcranial skeleton. Relationships among pulmonary components and skeletal regions they pneumatize allow inferences about pulmonary anatomy in non-avian dinosaurs. Fossae, foramina and chambers in the postcranial skeletons of pterosaurs and saurischian dinosaurs are diagnostic for pneumaticity. In basal saurisch...
متن کاملPostcranial skeletal pneumaticity and air-sacs in the earliest pterosaurs.
Patterns of postcranial skeletal pneumatization (PSP) indicate that pterosaurs possessed components of a bird-like respiratory system, including a series of ventilatory air-sacs. However, the presence of PSP in the oldest known pterosaurs has not been unambiguously demonstrated by previous studies. Here we provide the first unequivocal documentation of PSP in Late Triassic and earliest Jurassic...
متن کاملPostcranial pneumaticity: an evaluation of soft-tissue influences on the postcranial skeleton and the reconstruction of pulmonary anatomy in archosaurs.
Postcranial pneumaticity has been reported in numerous extinct sauropsid groups including pterosaurs, birds, saurischian dinosaurs, and, most recently, both crurotarsan and basal archosauriform taxa. By comparison with extant birds, pneumatic features in fossils have formed the basis for anatomical inferences concerning pulmonary structure and function, in addition to higher-level inferences re...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Integrative zoology
دوره 1 2 شماره
صفحات -
تاریخ انتشار 2006