Quetzalcoatlus
Size & Anatomy
Quetzalcoatlus Northropi has an estimated wingspan of around 11 m, while Q. lawsoni - though smaller - was still impressive at around 4.5 m. When standing on the ground, Q. Northropi was around 5 m tall, about the same height as a giraffe. Weight estimates vary significantly due to the lack of similar living animals to compare them to, but current generally accepted estimates are around 200 - 250 kg. It does not appear to have had a tail, which is unsurprising, as pterosaur tails generally became shorter throughout the Mesozoic era, eventually being almost lost by the end of the Cretaceous period. This likely improved maneuverability in the air.
Quetzalcoatlus had a very long neck - around 3 m, with its head being a similar length including a thin beak around 1.8 m long. Like other pterosaurs, the body of Quetzalcoatlus as well as parts of its wings were covered in pycnofibers - hair-like filaments. Pterosaurs, like dinosaurs, are thought to have been "warm-blooded", active animals.
What it Ate
The feeding behaviors of Quetzalcoatlus have been a subject of debate among paleontologists with many theories being suggested, but currently it is thought that they stalked prey on the ground - similar to modern-day storks. Skim feeding - flying over open water with the lower part of the beak submerged - has previously been suggested, but the necks of Azhdarchids like Quetzalcoatlus do not seem well-adapted to withstand the impacts/stress associated with this method of feeding. Their wings seem well-adapted for covering large distances but not for agile flying, suggesting that they likely did not hunt prey in the air. Finally, fossilized tracks have been found which suggest they were capable of walking efficiently on land on all four limbs.This efficient walking ability and stork-like beak, combined with a lack of adaptations for hunting aerial or aquatic prey, makes it very likely they were hunting prey on the ground and in shallow seas. The long, toothless beak of Quetzalcoatlus indicates that it likely targeted small prey that could be swallowed whole, such as fish, small vertebrates, juvenile dinosaurs, and carrion. Given the size of its beak and throat, if Quetzalcoatlus were alive today, humans might have been on its menu!
How They Lived
Quetzalcoatlus lawsoni fossils have been discovered in alkaline lake deposits, often found in groups. This has led to speculation that they may have lived or hunted socially and fed on small invertebrates in these lakes. However, it's challenging to confirm social behavior from fossils alone, as such groupings could occur for other reasons.The larger Q. Northropi is found in plains deposits - low, flat areas where rivers once flowed - leading some to suggest it may have led a more solitary life.
Could it Really Fly?
Another subject of debate has been how well Quetzalcoatlus could fly. Current evidence suggests that it was a proficient flier, capable of reaching speeds around 130 km/h. To initially get airborne, it is thought that Quetzalcoatlus used its strong forelimbs to launch itself into the air. Once airborne, it could flap its wings to get to a height at which it could soar like a condor - using rising thermal air currents to cover large distances. Pterosaurs, like modern birds, had hollow bones which reduced their weight, allowing even something as large as Quetzalcoatlus to take to the skies.
References & Attributions
Image: Size scale of Quetzalcoatlus - Matt Martyniuk (Dinoguy2), Mark Witton and Darren Naish, CC BY 3.0, via Wikimedia Commons
Image: Restoration of Quetzalcoatlus in flight - ДиБгд at Russian Wikipedia, Public domain, via Wikimedia Commons
Image: Skeletal Reconstruction of the smaller Quetzalcoatlus Lawsoni - Jaime A. Headden (User:Qilong), CC BY 3.0, via Wikimedia Commons
