(CNN)The oldest known fossils of dinosaur embryos have been examined in "unprecedented" detail to reveal how their skulls developed, according to a new study published Thursday.
Scientists reconstruct skulls of 200 million-year-old dinosaur embryos in 'unprecedented' 3D detail
Scientists used 3D technology to study eggs laid about 200 million years ago by five-meter long herbivore Massospondylus carinatus in South Africa.
The study has been published in Scientific Reports, part of the journal Nature.
Researchers from the University of the Witwatersrand in South Africa discovered that the skulls of dinosaurs developed in the same order as embryos of living dinosaur relatives -- crocodiles, chickens, turtles and lizards.
The eggs, discovered by scientists in 1976, are among the oldest known fossils of dinosaur embryos to have ever been unearthed.