WWD: Quetzalcoatlus northropi (Patreon)

With a wingspan of up to eleven metres across, standing as tall as a giraffe, and potentially weighing more than seven-hundred pounds, this is one of the largest animals to ever take flight, only rivalled by a few closely related (and contemporary) azhdarchids like Hatzegopteryx and Arambourgiania. Its skull alone was about eight feet in length. This is the only species here not definitively from Hell Creek, it's only known for sure from more southern fossil sites, the semi-arid environment where it coexisted with Alamosaurus (very young titanosaurs likely made up a significant portion of the pterosaur's diet), and the presence of azhdarchids from Hell Creek is only known from a single neck bone uncovered next to a Tyrannosaurus fossil, which isn't enough to determine whether it belonged to Quetzalcoatlus or another taxon (the neck bone belonged to a medium-sized species, with a wingspan only half as large as a Q. northropi adult). Although given Quetzalcoatlus lived on the same landmass and could fly, there's nothing we know of that would've prevented them from getting there. Q. northropi is also known from rather poor remains in spite of its fame, and most of its anatomy is extrapolated from the much smaller Q. lawsoni, which is known from much better fossils.

This is one of the animals which is a rather crude recycled model, in this case from the Ornithocheirus, and has aged very poorly. Because of being recycled from a totally unrelated animal it has a ton of anatomical oddities, such as a snout crest, a short neck, wings that are disproportionately long, a sprawled posture, and teeth in its beak. Part of this was the lack of knowledge on azhdarchid anatomy at the time, but even then liberties were taken. Even though Quetzalcoatlus remains are only known from semi-arid inland environments, it is presented as a seagoing fish-eater (another skim-feeder at that) and only a rare inland vagrant. Of course, the idea that pterosaurs could occupy niches beyond fish-eater and insect-eater was still controversial at the time. We now know they had long legs with ungulate-like proportions, which would've made it highly capable on land, possibly even allowing it to gallop, and it is now widely accepted azhdarchids were ground-based hunters of relatively large animals, probably capable of killing dinosaurs larger than humans.

Far from being the very last of the pterosaurs and "in decline", azhdarchids were one of the most successful animal groups alive at the time and their remains have been uncovered on every continent except Antarctica, indicating a cosmopolitan distribution for the group. In some places they would have even been apex predators. Fossils of Maastrichtian nyctosaurids and pteranodontids have also been uncovered, showing that pterosaur diversity was still relatively high even at the very end of the Mesozoic.