The world's oldest dinosaur embryos, some of which still feature organic material, have been found in Southwest China, researchers announced Wednesday.
A team led by Robert Reisz, a paleontologist with the University of Toronto—Mississauga, discovered 20 embryonic Lufengosaurus fossils. Lufengosaurus, a herbivore, was the largest dinosaur of its day, with some specimens growing up to 30 feet long. The fossils are more than 190 million years old.
The findings were published in the journal Nature Thursday.
Reisz says his team found a "colonial nesting site" where a group of lufengosauruses laid their eggs. In one of the fossils, the team found remnants of collagen, believed to be the oldest organic material of a dinosaur ever found. They also found pieces of eggshells, also considered to be the oldest ever found.
(Courtesy of Robert Reisz)
"We're looking at the beginning of the age of the dinosaurs, when they were just becoming the dominant terrestrial vertebrates of their time," he says. "To find organic remains is quite startling and surprising."
Reisz says that the team analyzed over 100 bones from the 20 fossils. The embryos were in different stages of development, which allowed them to make detailed conclusions about how the dinosaur developed. Unlike later dinosaurs, Lufengosaurus eggs were extremely thin and porous, perhaps because the dinosaurs developed quickly.
"When we find embryos we usually get one time slice of embryonic life because that was what was captured," he says. "What we see is a very high rate of growth—much faster than either living animals or other dinosaurs that we know of."
Despite the findings, don't start making vacation plans for Jurassic Park just yet – experts say reanimating the dinosaurs from embryos is "just a pipe dream."