Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 19 December 2008:
Vol. 322. no. 5909, pp. 1826 - 1828
DOI: 10.1126/science.1163245
Prev | Table of Contents | Next

Reports

Avian Paternal Care Had Dinosaur Origin

David J. Varricchio,1* Jason R. Moore,2 Gregory M. Erickson,3 Mark A. Norell,4 Frankie D. Jackson,1 John J. Borkowski5

The repeated discovery of adult dinosaurs in close association with egg clutches leads to speculation over the type and extent of care exhibited by these extinct animals for their eggs and young. To assess parental care in Cretaceous troodontid and oviraptorid dinosaurs, we examined clutch volume and the bone histology of brooding adults. In comparison to four archosaur care regressions, the relatively large clutch volumes of Troodon, Oviraptor, and Citipati scale most closely with a bird-paternal care model. Clutch-associated adults lack the maternal and reproductively associated histologic features common to extant archosaurs. Large clutch volumes and a suite of reproductive features shared only with birds favor paternal care, possibly within a polygamous mating system. Paternal care in both troodontids and oviraptorids indicates that this care system evolved before the emergence of birds and represents birds' ancestral condition. In extant birds and over most adult sizes, paternal and biparental care correspond to the largest and smallest relative clutch volumes, respectively.

1 Department of Earth Sciences, Montana State University, Bozeman, MT 59717, USA.
2 Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843, USA.
3 Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA.
4 Division of Paleontology, American Museum of Natural History, New York, NY 10024, USA.
5 Department of Mathematical Sciences, Montana State University, Bozeman, MT 59717, USA.

* To whom correspondence should be addressed. E-mail: djv{at}montana.edu

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
FACE BITING ON A JUVENILE TYRANNOSAURID AND BEHAVIORAL IMPLICATIONS.
J. E. PETERSON, M. D. HENDERSON, R. P. SCHERER, and C. P. VITTORE (2009)
Palaios 24, 780-784
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)