Tiny Dinosaur Fossil
A tiny dinosaur embryo bone found in a bed in Yunnan Province, China. The bones, which probably belonged to the long-necked Lufengosaurus, are among the oldest embryonic dinosaur bones ever discovered.
Yunnan Fossil Site
Researchers survey a fossil site in Yunnan, China, where they discovered more than 200 embryonic dinosaur bones. They reported their discovery April 11, 2013 in the journal Nature.
Digging for Dino Babies
Scientists huddle around the 3-foot (1-meter) square bone bed that once represented a Lufengosaurus nesting site.
Leg Bone Section
A cross-section of an embryonic dinosaur femur found in Yunnan, China. The honeycomb-like area is bone tissue with large spaces for blood vessels, indicating rapid growth of the bone.
Dino Bone Growth
Cross-sections of the smallest to largest Lufengosaurus femur bones, showing how the bones changed throughout embryonic development.
An artist's impression of Lufengosauarus inside the egg.
An artist's impression of an embryonic Lufengosaurus, showing the dinosaur's growing skeleton.
Lufengosaurus grew to be about 20 feet (6 meters) in length.
This is a close-up of an embryonic skeleton of the dinosaur Massospondylus from a clutch of eggs at the 190-million-year-old nesting site found in the Golden Gate Highlands National Park in South Africa. The Yunnan find and the South Africa find are about equal in age as the oldest known dinosaur embryos.
Another baby dinosaur find, this one from Mongolia. This nest contains the remains of 15 infant Protoceratops andrewsi, a sheep-sized plant-eater related to Triceratops.
The fossil remains of a nesting Oviraptor, dubbed "Big Mama," complete with eggs. When this fossil was originally discovered in the 1920s, paleontologists believed the oviraptor mama was preying on the eggs of another species. Turns out, they were hers.