While not an extant Herp, the idea of parental care in dinosaurs struck my interest while watching Jurassic Park the other day. A pair of angry T-Rex parents wreak havoc on scientists and veterinarians who abducted a young T-Rex, and the parents not only want him back, but they want revenge. With Dinisaurs being Arcosaurs and so closely related to birds and crocodilians, who both show signs of single and by-parental care, it would be completely reasonable for dinosaurs to have evolved some system of parental care as well. An article entitled "Dinosaurs showed signs of parental care: study", by Randy Boswell dated January 24, 2012 in the Montreal Gazette highlights the Canadian-led study on a 190 Million year old dinosaur nesting site in South Africa. The nesting site was apparently used by multiple female Massospondylus who nested together in groups and may have evolved a primitive form of maternal care. Fossils found range from eggs, embryos and juveniles. The theory is that because footprints and remnants of larger juvenile dinosaurs were found at the nesting site, hatchlings must have stayed near the nest until they were at least doubled in size. In order for these hatchlings to grow and survived they must have had some sort of support given by the mother, or perhaps group parental care. The research location has been incredibly helpful in helping to shed light on the reproductive behaviors in dinosaurs as the small cliff side site is home to 10 nests which housed the oldest found dinosaur eggs and embryos, and now evidence of nesting behavior. The research group hopes for more rock to be removed or eroded away so that more nests and information may be unveiled.
2 comments:
I find this post very interesting because I have never thought about dinosaurs having parental care. It would make perfect sense, as you mentioned, because they are archosaurs and must have evolved from an ancestor that engaged in parental care.
Since scientists have found dino egg fossils, do you think terrestrial dinosaurs were paedomorphic or metamorphic? I could see them being both, depending on their species. The dinosaurs that lived in or close to water may have been paedomorphic if their environment allowed that, or could have been biphasic where they started out in the water and then moved to land.
Also, since reptiles have to thermoregulate, do you think dinosaurs engaged in ways to cool off from convection and conduction, or those behaviors evolved after dinosaurs became extinct? I'm guessing they did to an extent but it is now in our current species that behavioral thermoregulation has really taken form and being used for maximum benefit.
Great blog entry!
Interesting article, Robbyn! Go mama archosaurs!
Hmmm, Lauryn, I seem to recall that direct development is a synapomorphy for the amniotes. Thermoregulation in dinos is a very interesting question!
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