The approximately 75-million-year-old nest shows 15 juvenile members of Protoceratops andrewsi—a relative of Triceratops—entombed in ancient sand dune deposits. The nest was recently discovered by Mongolian paleontologist Pagmin Narmandakh in the region's Djadokhta formation.
The 2.3-foot-wide (0.7-meter-wide) nest is breathtaking, according to David Fastovsky, a co-author on a paper about the dinosaur nest published in the November edition of the Journal of Paleontology.
Unlike other dinosaur nests found with fossil eggs, the babies in this nest appear to have been about a year old when they died.
(Related picture: "Birdlike Dinosaur Eggs Found.")
"We think there's good evidence for some sort of parental care, because these animals are growing together at the nest," said Fastovsky, a paleontologist at the University of Rhode Island. "They did not come fresh out of eggs two minutes ago."