SUNDAY, 11 FEBRUARY 2018Pterosaurs were the the dominant airborne animals of the Mesozoic Era (252-66 million years ago), dying out alongside the dinosaurs and being ecologically replaced by birds. However, a new study by Xiaolin Wang et al. seems to suggest that pterosaurs often used the same evolutionary strategies as their avian replacements. Fossilised embryos of Hamipterus, a Chinese cousin of the famous Pteranodon, were found still inside their eggs and subsequently analysed; this revealed that, in spite of the eggs being close to hatching, many of their bones lacked proper ossification. Wang et al. thus hypothesise that new-born Hamipterus were unable to fly, and relied on their parents for food. This, along with the fact that over 100 eggs were found on one site over 4 consecutive geological levels, could mean that Hamipterus nested like modern seagulls and puffins, in large long-term colonies.
This strategy probably isn’t universal across pterosaurs. 2011 work by Junchang Lü et al. on Darwinopterus suggested that this species buried and abandoned their eggs in a similar fashion to sea turtles, with the young being able to fly immediately after hatching. This reflects the diversity of pterosaur life histories, and explains in part why the group was so successful.
Header image: Jes