Oldest Known Dinosaur Nesting Site Found01/25/12
WEDNESDAY, Jan. 25 (HealthDay News) -- Researchers who found the
earliest known dinosaur nesting site say it offers significant
clues about the evolution of complex reproductive behavior in early
The 190-million-year-old site in South Africa is 100 million
years older than previously known nesting sites. It contains
clutches of eggs of the prosauropod dinosaur
Massospondylus, a relative of the giant, long-necked sauropods of the Jurassic and Cretaceous periods. Many of the eggs contain embryos.
There are also tiny dinosaur footprints, which provide the
oldest known evidence that hatchlings remained at the nesting site
long enough to at least double in size.
At least 10 nests, each with up to 34 round eggs in tightly
clustered clutches, have been found at several ground levels at the
site. The fact that there are nests at different levels in the
sediment indicates that the dinosaurs returned repeatedly to the
site and likely gathered in groups to lay their eggs.
This is the oldest known evidence of such behavior in the fossil
record, according to Robert Reisz, a paleontologist and professor
of biology at University of Toronto.
The mothers were 6 meters long and the eggs were about 6 to 7
centimeters in diameter. The highly organized nature of the nests
suggests that the mothers carefully arranged the eggs after they
"The eggs, embryos and nests come from the rocks of a nearly vertical road cut only 25 meters long," Reisz said in a university news release. "Even so, we found ten nests, suggesting that there are a lot more in the cliff, still covered by tons of rock. We predict that many more nests will be eroded out in time as natural weathering processes continue."
The research appears in this week's issue of the
Proceedings of the National Academy of Science.
Smithsonian as more on
Copyright © 2012
. All rights reserved.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.