A group of biologists and paleontologists from the British universities of Lincoln (United Kingdom) and Saint Andrews, and from the North American University George Mason (Virginia), have studied the causes why the largest dinosaurs that walked the Earth laid many more eggs small than would be expected based on their size.
And it is that dinosaurs, especially sauropods, among which the diplodocus is counted, stood out for their enormous dimensions . That is why scientists were intrigued by the fact that both the eggs and the nest where they laid were so small, even compared to those of current oviparous animals.
According to this research, which is published in the journal Paleobiology , of the Paleontological Society, the incubation time that sauropod embryos needed to develop and hatch must have been an important limitation that could explain the issue.
Taking into account data from the egg-laying of modern birds and reptiles, the scientists calculated that the incubation time in underground nests of dinosaurs, from laying to hatching, would last between 65 and 82 days. This presented more opportunities for predators, which, together with the relatively low temperatures at the laying sites, would have been important factors in limiting the size of each egg and the nest as a whole.
Had the eggs been larger than those in the fossil record, hatching would have been easier, but it would also have attracted more predators during incubation.
Charles Deeming, from the School of Life Sciences at the University of Lincoln, thinks that “the long incubation periods of the sauropods must have produced a high mortality rate from predation. That is why we believe that the females laid their eggs in small nests, possibly distributed in different places, as an adaptive strategy to defend the future offspring from predators ”.
Professor Ruxton, from the Faculty of Biology at the University of Saint Andrews, adds that “today’s birds with the largest eggs, which are ostriches, incubate for 42 days, and in that time, many are eaten by other animals. An ostrich weighs about 100 kilos and lays one and a half kilo eggs. A sauropod dinosaur was supposed to weigh 50 times more, but its eggs were only slightly larger than those of the ostrich . Now we know why ”.
