Dec 22, 2021
The link between dinosaurs and birds has become even more clear! A rare, well-preserved embryo found inside a fossilized egg reveals striking similarities between dinosaurs and the birds they would evolve into, researchers say. The egg dates back more than 66 million years.
In a study published in the journal iScience, the authors reported that they discovered the embryo curled up with its head between its legs. Scientists used to think that position was unique to birds. The egg is 7 inches long and oval shaped.
The fossil also revealed a head and beak similar to that of a newly hatched bird. But the dino had tiny arms and claws rather than wings and could not fly.
One of the study's authors called the fossil “one of the best-preserved dinosaur embryos ever found.” The egg arrived at a nature museum in China in 2000 along with a large number of fossils. It took another 15 years for staff to realize what lay inside the egg. Scientists detected bones that had fossilized after the egg cracked. Careful analysis revealed the complete fossil curled up in its shell.
Discoveries of embryonic dinosaur fossils are very rare. They have been found at only about a half-dozen sites.
Photo from iScience.
Extinction
This resource discusses what it means for a species to go extinct, how species evolve over time, and why many species on Earth are going extinct at increasingly faster rates.
Why Climate Matters
This course explains how climate change impacts people, the economy, extinction, life on land, and ocean life.
Climate Change in Earth History
In this interactive textbook lesson, students will discover factors that can naturally alter the climate such as volcanoes, plate tectonics, and asteroids.