amniote
; animal cell
; Conference Paper
; Cretaceous
; crocodilian
; development
; developmental stage
; dinosaur
; embryo
; embryo development
; growth
; hatchling
; incubation time
; mass extinction
; nonhuman
; Paleogene
; priority journal
; reptile
; reptilian grade development
; squamate
; tooth crown
; tooth development
; anatomy and histology
; animal
; bird
; dinosaur
; embryology
; evolution
; female
; fossil
; reptile
; species difference
; species extinction
; tooth
; tooth development
; Animals
; Biological Evolution
; Birds
; Dinosaurs
; Extinction, Biological
; Female
; Fossils
; Odontogenesis
; Reptiles
; Species Specificity
; Tooth
英文摘要:
Birds stand out from other egg-laying amniotes by producing relatively small numbers of large eggs with very short incubation periods (average 11-85 d). This aspect promotes high survivorship by limiting exposure to predation and environmental perturbation, allows for larger more fit young, and facilitates rapid attainment of adult size. Birds are living dinosaurs; their rapid development has been considered to reflect the primitive dinosaurian condition. Here, nonavian dinosaurian incubation periods in both small and large ornithischian taxa are empirically determined through growthline counts in embryonic teeth. Our results show unexpectedly slow incubation (2.8 and 5.8 mo) like those of outgroup reptiles. Developmental and physiological constraints would have rendered tooth formation and incubation inherently slow in other dinosaur lineages and basal birds. The capacity to determine incubation periods in extinct egg-laying amniotes has implications for dinosaurian embryology, life history strategies, and survivorship across the Cretaceous-Paleogene mass extinction event.
Erickson, G.M., Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, United States; Zelenitsky, D.K., Department of Geoscience, University of Calgary, Calgary, AB T2N 1N4, Canada; Kay, D.I., Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, United States; Norell, M.A., Division of Paleontology, American Museum of Natural History, New York, NY 10024, United States
Recommended Citation:
Erickson G.M.,Zelenitsky D.K.,Kay D.I.,et al. Dinosaur incubation periods directly determined from growth-line counts in embryonic teeth show reptilian-grade development[J]. Proceedings of the National Academy of Sciences of the United States of America,2017-01-01,114(3)