Paleontologists have discovered the oldest dinosaur nursery on Earth

What's the only thing better than dinosaurs? That would be baby dinosaurs. Paleontologists working in South Africa have made an incredible discovery in the region's Golden Gate Highlands National Park: 10 nests thought to belong to the herbivorous dinosaur Massospondylus, a forbear of massive sauropods like Brachiosaurus.

Many of the nests contain eggs. Others are spotted with tiny footprints. But the most incredible thing about this find is how old the nesting site is — at 190 million years old, this nursery predates all previously known nesting sites by 100 million years.

In an article published in today's issue of Proceedings of the National Academy of Sciences (which, evidently, has yet to come out from under embargo EDIT: The paper is now available online), paleontologist Robert Reisz and his colleagues conclude that their findings provide the oldest known evidence that newborn dinosaurs hung around their nesting sites long enough after hatching to at least double in size.

Why is that important? For one thing, it speaks volumes about the nesting behavior of baby Massospondylids, not to mention the broader social nature of the entire species. LiveScience's Charles Choi expands on this idea:

...The site seemed to be a popular one for dino day care, as the nests were found in at least three distinct layers of rock within the excavation, each indicating a different point in time. In fact, the researchers suggest the dinosaur moms likely returned repeatedly to the site. Also, the fact that multiple nests were found within the same layers - and thus were laid at about the same time - reveals the dinosaurs likely gathered in groups to lay their eggs, the oldest evidence of such behavior in the fossil record.

According to David Evans, curator of vertebrate paleontology at the Royal Ontario Museum in Canada, the discovery sheds some much-needed light on the reproductive behavior of early dinosaurs.

"Even though the fossil record of dinosaurs is extensive, we actually have very little fossil information about their reproductive biology, particularly for early dinosaurs," explains Evans. He continues:

This amazing series of 190 million year old nests gives us the first detailed look at dinosaur reproduction early in their evolutionary history, and documents the antiquity of nesting strategies that are only known much later in the dinosaur record.

Read more about this unprecedented discovery over on LiveScience.
Artist's interpretation of 190-millon-year-old Massospondylusnests, eggs, hatchlings and adults by Julius Csotonyi