Oldest Dinosaur Embryo Found in Massospondylus Egg

Paleontologists Robert R. Reisz, David C. Evans, and others from the American Museum of Natural History have announced the results of their investigation of a Massospondylus egg fossil containing the oldest dinosaur embryo.

Inside the egg, believed to be from the Early Jurassic, was a 20 cm long baby Massospondylus carinatus just before hatching.
Although Massospondylus was an early bipedal sauropodomorph that grew to 4 meters, the baby had a different body shape from the adult. It was found that the baby had long forelimbs and was likely quadrupedal.

The egg fossil investigated this time was found in 1976 near the border of South Africa. Advances in analysis technology, such as high-performance microscopes, made a detailed investigation possible.