In northwestern China, scientists have discovered more than 200 fossil eggs and bones of the pterodactyl Hamipterus tianshanensis. The find is a sensation, because so far only a handful of pterosaur eggs were discovered - the first in 2004. It is also particularly that the bones come from differently old individuals and that in 16 eggs the remains of embryos were found. Xiaolin Wang and Shunxing Jiang of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing who excavated the fossils, and Alexander Kellner of the National Museum of the Federal University of Rio de Janeiro, who helped with the analysis, draw two conclusions from their find: Hamipterus tianshanensis lived in larger colonies and the young were dependent on parental care.
Bones, cartilage, controversy
In a particularly well-preserved egg, Kellner discovered that the embryonic posterior extremities were more developed than the anterior ones, and that much of his cartilage was not yet ossified. "This suggests that the pterosaurs were able to walk after hatching but could not fly." In addition, unlike other dinosaur embryos, the embryos were toothless. According to Kellner, both findings indicate that the descendants of Hamipterus tianshanensis were not yet able to hunt independently and had to be fed by older animals.
These conclusions fuel heated controversy. David Unwin, paleontologist at the University of Leicester, warns that, after analyzing fewer eggs, he will draw binding conclusions. Other colleagues such as Mark Witton of the University of Portsmouth have even announced the publication of a study with opposing positions. display
Photo: Wang et al., Science (2017)© science.de - Jana Burczyk