The tiny armored dinosaur, smaller than a playing card, apparently drowned not long after it hatched during the Early Cretaceous Period and was fossilized, awaiting its discovery in 1997, The Baltimore Sun reported Tuesday.
In an article published in the Journal of Paleontology, Stanford and Johns Hopkins University scientist David Weishampel described the creature and gave it its name.
The animal was the youngest "nodosaur," or armored dinosaur, ever discovered and the first hatchling of any species ever found in the eastern United States, he said.
"Now we can learn about the development of limbs and the development of skulls early in a dinosaur's life," Weishampel said.
"The very small size also reveals that there was a nearby nesting area, or rookery, since it couldn't have wandered far from where it was hatched," he said, noting small nodosaur footprints were found nearby.
Had it lived, Weishampel said, it would have grown to be 20 to 30 feet long.