A rare scientific study on the embryos of dinosaurs concludes their eggs had astoundingly slow incubation periods.
Although dinosaurs are predominantly thought to be more closely related to birds than reptiles, recent analysis proves that many of them display non-avian reproductive characteristics, supporting the theory of a distinct differentiation between two groups of dinosaurs based on their closest living relatives.
Birds hatch eggs with short incubation periods, spanning the length of 11-85 days — three months at most, depending on the size of the egg. Research performed by experts out of Florida State University published in the Proceedings of the National Academy of Sciences concluded that dinosaur eggs of similar size took twice as long to hatch as avian eggs, more closely resembling their crocodilian ancestors.
Precise dental record scrutiny was performed on embryos from two different species with vastly distinct egg sizes — the smaller Protoceratops and the larger Hypacrosaurus. CT scanning and an understanding of growth rings on the teeth of embryos allows scientists to adequately determine how long eggs incubate.
The Protoceratops was concluded to have an egg incubation time of about three months, whereas the bigger Hypacrosaurus eggs incubate six months before hatching. These findings raise discords among what is currently understood about dinosaurs.
Longer incubation periods equate to greater environmental risks for offspring including storms, floods, and exposure to predators. Extended hatching periods also interfere with the theory of dinosaur migration between temperate and Arctic climates as well as juxtapose the importance of parenting.
Further research must be done to evaluate the implications of the longer incubation periods of dinosaur eggs, but one sure conclusion is that it was probably a factor in their eventual demise.