What an embryo looks like in the most ancient dinosaur egg (7 photos)

In 1976 in South Africa in the National Park Golden A gate located in the Free State, north of Lesotho, has been discovered dinosaur egg laying. They were set aside by a species known as Massospondylus, about 190 million years ago, making them one of the oldest dinosaur eggs found in the world.





Fossilized dinosaur eggs with embryos.

Massospondyls were bipedal dinosaurs about six feet tall. meters and weighing about one ton, with a barrel-shaped chest, a long thin neck and small almost square head. Appearing at the end Triassic period about 200 million years ago, they were part of groups of sauropodomorphs - the early ancestors of the giant sauropods of the Cretaceous period.



Reconstruction of Massospondylus showing it bipedal.

The size of the embryos suggested that the cubs were probably close to hatching before they were quickly buried and petrified. However, re-examination showed that these embryos were at an earlier stage of development.

Dr. Vincent Fernandez, specialist in micro-CT scan from London's Natural History Museum, worked with South African colleagues, Dr. Kimberly Chapel and Dr. John Choigner to scan and visualize the samples.



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Scanned skull of an embryo before reconstruction.

They managed to scan the embryos, after which Chapel meticulously stitched together the images to create a 3D model of the fetal skull dinosaur - one of the best ever created.

It was originally thought that these embryos were about to hatch because their bones look well developed, but scientists now estimate that they have only gone through about 60% of the period development.



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Reconstructed skull of a dinosaur embryo.

Embryo studies show that although adults were bipedal, the young had completely different body proportions and, probably moved on all fours. As the animals grew, their proportions changed, and they became more bipedal.

Delivering the fossil to the European Synchrotron Facility radiation in Grenoble (France), the team was able to get a scan embryos to the level of individual bone cells. Embryos inside eggs scan because their bones are not fully developed: poorly ossified and, as a result, are poorly fossilized and their density is similar to that of the surrounding material.



Dinosaur eggs discovered in 1976.

Kimberly Chapel compared the find with bird eggs, as well as with embryos of crocodiles, lizards and turtles. It is thanks to this By comparison, she was able to understand that the babies in the eggs were much younger, than previously thought.

In addition, the scan showed that the skulls of the embryos dinosaurs develop in the same order as the skulls of modern crocodiles, chickens, turtles and lizards, and besides, these embryos inside The eggs developed two types of teeth. They had so-called teeth "zero generation". In crocodiles and lizards such as geckos, the first a set of teeth falls out while still in the egg. Embryos have similar teeth on the teeth of adults, and others were lost before hatching, completely thin, thinner toothpicks.



Adult Massospondyl and calf.

Studies have identified the first case of such a change in the set of teeth in dinosaurs are still in the egg, which means that this species developed inside their eggs in the same way as their reptile relatives, and this process does not changed over hundreds of millions of years.



Size comparison of Massospondyl and human.

Scientists believe that such a mechanism can be applied and for other dinosaur species and hope to look at other embryos dinosaurs and compare their development.