World’s best-preserved duck-billed dinosaur embryo fossils discovered in China

Two fossils containing the most complete duck-billed dinosaur embryo ever scientifically recorded have been discovered in the Ganzhou Basin, Ganzhou city, east China’s Jiangxi Province, according to a research paper published on May 11, 2022.

Photo shows a life reconstruction of the “Ying Baby.” (Photo courtesy of the Yingliang Stone Natural History Museum)

The research paper, co-authored by researchers from China and Canada, was published in the journal BMC Ecology and Evolution.

The fossils, which date back to 66 million to 72 million years ago, are now preserved at the Yingliang Stone Natural History Museum in southeast China’s Fujian Province. The museum has called the specimens the “Ying Baby.”

The egg of the specimens is an ellipsoid with a diameter of around 9 centimeters and a total volume of about 660 milliliters. The embryo fills about 40 percent of the egg.

Photo shows a duck-billed dinosaur embryo fossil. (Photo courtesy of the Yingliang Stone Natural History Museum)

Judging by the unique shape of the skull, vertebrae and limb bones of the embryo, scientists have inferred that it belonged to a duck-billed dinosaur, or hadrosaurids, a class of large herbivore dinosaurs that lived at the end of the dinosaur era and was characterized by its duck-like flat beaks.

While this is not the first time that such a kind of embryo has been found, the Ying Baby is by far the best-preserved one ever discovered.

The tiny size of both the egg and embryo implies that duck-billed dinosaurs had small eggs and late body development as a primordial feature, which is one of the most important new pieces of information that this discovery has contributed to our understanding on the development of dinosaur species.

Photo shows a duck-billed dinosaur embryo fossil. (Photo courtesy of the Yingliang Stone Natural History Museum)

Back in December 2021, a research team consisting of scientists from China, the UK, and Canada, also discovered a perfectly preserved dinosaur embryo fossil, which is believed to be the best dinosaur embryo specimen ever found to date and is now being housed at the Yingliang Stone Natural History Museum. 

Photo shows duck-billed dinosaur embryo fossils preserved at the Yingliang Stone Natural History Museum. (Photo courtesy of the Yingliang Stone Natural History Museum)