Well-preserved fossil of bird-like dinosaur sitting atop nest of eggs discovered in Spain

In a new revelation, scientists have discovered a fossil of an oviraptorosaur which is a type of bird-like theropod dinosaur usually found sitting on the top of nests that contain eggs. According to the reports by Phys.org, the species belongs to the Cretaceous Period, which is also the third and final time period of the Mesozoic Era that extended from 145 to 66 million years ago. The new specimen, which is 70 million years old, was recovered from uppermost Cretaceous-aged rocks in Ganzhou City in China’s Jiangxi Province. 

'Rarest of the rare'

The fossil contains an incomplete skeleton of an adult oviraptorid sitting in a hatching position. It has been found very close to a bird on a clutch of 24 eggs. Dr. Shundong Bi explains that dinosaurs which are preserved on the nests are ‘rare’. He further highlighted that this is the first time a non-avian dinosaur has been found, sitting on a nest of eggs that preserve embryos. Also, this has been found in a single spectacular specimen. 

(Geological map of the eastern part of the Tremp Syncline with the location of the Sant Romà d’Abella site. Image Credits: Nature.com)

(Landscape view of the fossil site. Image Credits: Nature.com)

Dr. Albert Sellés, a paleontologist in the Institut Català de Paleontologia Miquel Crusafon at the Universitat Autònoma de Barcelona, along with his team said, "During the latest Cretaceous (77-66 million years ago) in the run-up to the end-Cretaceous mass extinction, Europe was a series of islands populated by diverse and distinctive communities of dinosaurs and other vertebrates". The paleontologists further added, "Many of these animals exhibited peculiar features that may have been generated by lack of space and resources in their insular habitats". 

Out of the 24 eggs, at least 7 eggs preserve bones or partial skeletons of unhatched oviraptorid embryos inside. Also, the late stage of development of the embryos suggests that the latter died during its incubation in the nest. According to the reports by Phys.org, Dr. Lamanna explained that such a discovery is ‘rarest of the rare’ in dinosaurs. 

He further explained that a few oviraptorids have been found on nests of their eggs before but no embryos have ever been found inside those eggs. The new specimen shows that the babies were almost ready to hatch. This reveals that this oviraptorid had tended its nest for a long time. Also, this highlights that this dinosaur was a caring parent that ended up giving its life while nurturing its young one. As a part of the study, the team conducted oxygen isotope analyses. It was then concluded that the eggs were incubated at high, bird-like temperatures. Also, even though all embryos were well developed, some appear to have been more mature than others.

(Image Credits: RepresentativeImage/Unsplash)