Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-6-9
pubmed:abstractText
In terms of their diversity and longevity, dinosaurs and birds were/are surely among the most successful of terrestrial vertebrates. Unfortunately, interpreting many aspects of the biology of dinosaurs and the earliest of the birds presents formidable challenges because they are known only from fossils. Nevertheless, a variety of attributes of these taxa can be inferred by identification of shared anatomical structures whose presence is causally linked to specialized functions in living reptiles, birds, and mammals. Studies such as these demonstrate that although dinosaurs and early birds were likely to have been homeothermic, the absence of nasal respiratory turbinates in these animals indicates that they were likely to have maintained reptile-like (ectothermic) metabolic rates during periods of rest or routine activity. Nevertheless, given the metabolic capacities of some extant reptiles during periods of elevated activity, early birds were probably capable of powered flight. Similarly, had, for example, theropod dinosaurs possessed aerobic metabolic capacities and habits equivalent to those of some large, modern tropical latitude lizards (e.g., Varanus), they may well have maintained significant home ranges and actively pursued and killed large prey. Additionally, this scenario of active, although ectothermic, theropod dinosaurs seems reinforced by the likely utilization of crocodilian-like, diaphragm breathing in this group. Finally, persistent in vivo burial of their nests and apparent lack of egg turning suggests that clutch incubation by dinosaurs was more reptile- than birdlike. Contrary to previous suggestions, there is little if any reliable evidence that some dinosaur young may have been helpless and nestbound (altricial) at hatching.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
1522-2152
pubmed:author
pubmed:issnType
Print
pubmed:volume
76
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
141-64
pubmed:dateRevised
2005-11-16
pubmed:meshHeading
pubmed:articleTitle
Respiratory and reproductive paleophysiology of dinosaurs and early birds.
pubmed:affiliation
Zoology Department, Oregon State University, Corvallis, OR 97331-2914, USA. rubenj@science.oregonstate.edu
pubmed:publicationType
Journal Article, Review