From Skim Feeders to Cursorial Predators
When azhdarchids were first found, we assumed they were just like any other pterosaur. We thought that pretty much all pterosaurs were fish eaters. However, we know that's not the case. We have flightless pterosaurs, like Sos 2428, and the frugivorous tapejarids, the aerial predators like Harpactognathus, and then we have azhdarchids. At first, because of their long spear like beaks, we thought they were skim feeders, kind of like the skimmers, which are birds that have a longer lower jaw and a shorter upper jaw, which they use for skimming the water until they catch fish. In fact, many pterosaurs, including Rhamphorhynchus were thought to fish like this, but we know know that it probably isn't likely. The same goes for the azhdarchids. There are several problems that go with this idea:
1. Azhdarchids have long, inflexible necks, and their jaws are not like those of modern day skimming birds.
2. There have been no fossils of azhdarchids found in marine deposits, all in terrestrial (sometimes arid) environments.
Others suggested they were scavengers, but their jaws are also not like those of scavenging animals. So, what were they doing? In 2008, a paper was published by Mark Witton, and Darren Naish, arguing that azhdarchids were cursorial predators, possibly preying upon baby dinosaurs! In fact, their long limbs and unspecialized beaks suggest that they filled a niche similar to storks. In addition, there is evidence that azhdarchids traveled in groups when they stalked the ground. As if that isn't scary enough, these guys probably could run! Not waddle, but, RUN! They may have even taken on prey about the size of humans! So imagine a group of the biggest flying vertebrates on Earth chasing you down! Scary, huh?
An interesting note is that some inland late Cretaceous communities which have large azhdarchids were absent of midsize dinosaur predators. This suggests they actually filled the role of midsize predators in some areas!
So, this is a short post basically listing the reasons why azhdarchids are my favourite pterosaurs. If I do get something factually wrong, just tell me and I'll change it. I'm still getting used to this. Anyways, until next time!