110-million-year old fossil bird found with egg in

Scientists say that it is “incredibly well preserved”, that dates from the time of the dinosaurs, casts a new light on the reproduction of birds. The sample, that a new species called Avimaia schweitzerae, was discovered in 110-million-year-old deposits in the northwest of China. (Credit: SWNS)

A beautiful new discovery is shedding light on the very first bird fossil found of an egg preserved in.

The find, made in the 110-million year old deposits in the northwest of China, is a new kind of known as Avimaia schweitzerae and the fossil was described as “incredibly well-preserved.” The new species belongs to the group known as the Enantiornithes, which are quite common in the cretaceous period, living alongside the dinosaurs.

However, the fossil egg may have resulted in the death of the so-called ” mother bird, researchers said.


“The egg-shell consists of two layers instead of one, as in a normal, healthy bird eggs, with mention of the egg was kept too long in the stomach,” Dr. Alida Bailleul said in a comment that is obtained by SWNS.

“This condition often occurs in living birds as a result of stress,” she continued. “In addition, the eggshell preserved in Avimaia was extremely thin – thinner than a sheet of paper and does not have the correct proportions of healthy eggs. These deviations suggest that the preserved egg can be the cause of the death of this ” mother bird.'”

Bailleul added that this type of deviation is seen elsewhere in the animal kingdom, including in sauropod dinosaurs, “as well as in many fossil and living turtles.”

Since the fossil was crushed, it was only after the researchers extracted a small fragment, and analyzed did they realize the particular tissue of an egg. The preparation contains not only the eggshell itself, but also the membrane and the cuticle, which are largely made up of proteins and other organic materials.

The sample, that a new species called Avimaia schweitzerae, was discovered in 110-million-year-old deposits in the northwest of China. It belongs to a group called the Enantiornithes – “opposite birds” – which were common all over the world during the Cretaceous Period, and lived alongside the dinosaurs. (Credit: SWNS)

“SEM shows that the epidermis consists of nanostructures similar to those found in neornithine eggs adjusted for infection-sensitive environments, which are assumed to represent the ancestral avian condition,” the study abstract reads.

Dr. Jingmai O’connor, a co-author of the study, said that the morphology of the to be expected for birds that bury their eggs, but this discovery “also supports the hypothesis that a cuticle with a protective spheres represents the ancestral condition for avian eggs.”


“Avimaia is the only Mesozoic fossil in which additional morphological evidence of reproductive activity, i.e. the egg – supports the identification of medullary bone,” O’connor continued. “This new instance is perhaps one of the most interesting Cretaceous fossil birds have not yet discovered, providing more reproductive information than any other Mesozoic fossil bird.”

The study is published in Nature Communications.

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