World Socialist Web Site wsws.org 17 Mar, 2021 02:30 am

Dinosaur fossil found sitting on eggs in a nest reveals well-developed parental care

Dinosaur fossil found sitting on eggs in a nest reveals well-developed parental care
The fossil, dating to 70 million years ago, consists of the partially preserved remains of an oviraptorosaur, a feathered, theropod dinosaur lineage tangentially related to those that eventually gave rise to modern birds.

The fossil, dating to 70 million years ago, during the Cretaceous Period, which ended with the mass dinosaur extinction, consists of the partially preserved remains of an oviraptorosaur, a feathered, theropod dinosaur lineage tangentially related to those that eventually gave rise to modern birds.” According to the CMNH press release, the embryos were at a late stage of development, implying that the adult was actually sitting on the nest incubating the eggs, as is done by many modern birds, rather than that the eggs had been recently deposited to then be left to develop on their own (as is done by modern reptiles).” The interpretation that these dinosaur parents actively incubated their eggs is further supported by the result of oxygen isotope analysis, which indicates that the eggs were maintained at a high temperature, similar to that of modern birds, consistent with the idea that a parent was more or less continually sitting on the nest.This resembles the pattern in some modern birds, known as asynchronous hatching, which means that the offspring emerge from their shells over a somewhat extended period of time.

This evidence of advanced parental care among at least one group of dinosaurs, which are closely related to the ancestors of modern birds, raises interesting questions about other aspects of behavior among these long extinct animals.A multinational team recently announced a fossil dinosaur discovery in China that provides new evidence of advanced parental care among at least one group of the earth’s once dominant vertebrate animals.

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