On the 23rd of this month, the National Museum of Natural Sciences of Argentina announced that,An international team of paleontologists discovered a complete dinosaur egg fossil dating back about 70 million years in the late Cretaceous strata of the Rio Negro province in Patagonia., this is the first complete egg fossil of a small carnivorous dinosaur discovered in South America.
The egg's preservation condition can be described as "perfect". The surface of the eggshell is smooth and crack-free, and the whole body is snow-white, like a hard-boiled egg. The shape is similar to an ostrich egg, with a diameter of about 11-12 centimeters and a weight of about 500 grams.
The reason why it is so intact is that the egg body was quickly buried by volcanic ash, forming a natural "protective layer".Not only the microstructure of the eggshell (such as stomata distribution and calcium crystal morphology) is completely preserved, but the internal embryonic tissue may also be sealed..
The research team has found through CT scans that there are areas of abnormal density within the eggs, which they speculate may be the remains of embryonic bones or unhatched soft tissues.
Preliminary identification showed thatThe egg belonged to Bonapateonychus, a turkey-sized dromaeosaurid dinosaur that was only 1.5 meters long and lived in the late Cretaceous period (about 70 million to 66 million years ago).
Scientists plan to use synchrotron radiation X-ray microscopic imaging technology to conduct 3D reconstruction of the egg body and analyze the embryonic bone structure without destroying the fossil.
It is worth mentioning that snake vertebrae and mammal tooth fossils were also found in the same area, indicating that this was once a "nursery" for dinosaurs.
Paleontologists speculate thatBonapateonychus may have nested in clusters like modern birds, using vegetation to cover the nest to maintain temperature and humidity. This reproductive strategy is the first to be discovered among small carnivorous dinosaurs..
