New pterosaur species and their eggs discovered in China

This 6 June 2014 video is called First 3D Flying Reptile Eggs Discovered in China.

Getting ahead: the new crested pterosaur Hamipterus has researchers aflutter

The newly discovered Chinese flying reptile is preserved in huge numbers and with rarely found eggs

The pterosaurs have often been the poor cousins of their relatives when it comes to the public’s understanding of them. Incorrectly called flying dinosaurs, mixed up as bird or even bat ancestors, and considered leathery-winged gliders that could barely fly, let alone walk, they remain a relic of the ‘animals are extinct because they failed’ idea of the 1800s. In fact pterosaurs were remarkably good fliers and many were also superb on the ground, and their real limitation is that their fossil record is generally so poor.

Pterosaurs had incredibly thin bones and while this may have helped make them relatively light, it means they did not fossilise well. As a result, we don’t have many good pterosaur skeletons (and rarely have multiple individuals of one species), and the ones we do have tend to come from a few restricted places where the preservation at that time was exceptional. Pterosaur eggs are even more rare, with all of none turning up between 1784 (when the first pterosaur was described) and 2004, and in the last decade that number has reach a grand total of four.

So the announcement of a discovery of a whole pile of pterosaurs, and with several eggs as well, is clearly a tremendous find. The newly named Hamipterus tianshanensis (its name roughly means ‘the wing of Hami, in the Tianshan mountains’) is from Xinjiang of northwestern China, and dates to around 100-120 million years ago. The fossils uncovered in this arid region include bones of at least 40 different individuals (and estimates of the number of pterosaur bones in the area run into the thousands) and so far five eggs. That is quite a haul and immediately makes this one of the better represented pterosaurs and makes the area a prime spot for pterosaur research. Moreover, all previously described pterosaur eggs had been flattened into two dimensions, but the ones preserved here are the first even that are available in 3D (if a little squished).

Hamipterus was a medium sized pterosaur with a wingspan of up to 3.5 m. It is referred to a group of pterosaurs called the pteranodontoids which include the famous toothless Pteranodon, but also numerous other pterosaurs including many with large teeth. Members of this group are generally considered to be primarily fish eaters and excellent fliers, catching their food on the wing by snatching fish from the surface of the water. The anatomy of the new find matches this interpretation with a series of long teeth in the thin jaws, and the bones were buried around the margin of a large lake. However, it is in the shape of the top of the head that the real interest lies, with specimens bearing a bony crest that runs along the top of the skull and is much larger in some individuals.

Pterosaurs are in part famous for the wild variety of head crests seen on various species. These include those composed of bone, others of soft tissues and some that combined the two. Over the years various hypotheses have been brought forwards for their function, but the main prevailing idea is that in most forms they likely functioned in some forms of sexual display and / or as social dominance signals. In the case of Hamipterus it is suggested that the different sizes may represent males and females (with the males bearing the larger crest) which is very much a reasonable starting hypothesis, but one that requires a degree of further testing. There’s a huge variation in the size and shape of crests in various things that have them (look at the horns in sheep and antlers in deer) and telling male from female, or young male from old male and so on, can be very difficult.

The data is naturally limited at the moment, but the fact that already numerous different individuals and eggs have turned up together is the first on record. There is obviously the potential here for many more animals to be found, and comparable big aggregations of nesting animals are already known for both ancient birds and non-avian dinosaurs. It would not at all be a surprise if pterosaurs did something similar, and indeed this has been suggested in various quarters a number of times, so thepossibility is there, even if it is currently very tentative. Such a haul of specimens though provides an excellent starting point and there is certainly much more to come from this amazing collection.

Wang et al., Sexually Dimorphic Tridimensionally Preserved Pterosaurs and Their Eggs from China, Current Biology (2014), http://dx.doi.org/10.1016/j.cub.2014.04.054.