Scientists have made a groundbreaking discovery regarding the evolution of pterosaurs, the largest flying creatures to have ever lived. In a surprising twist, researchers have found that the ability of these ancient reptiles to walk on the ground played a crucial role in their growth to enormous sizes.
Originally small tree-climbers, pterosaurs eventually evolved to have wingspans of up to 10 metres, similar to small planes. The University of Leicester researchers believe that pterosaurs became giants, weighing up to 250kg, due to evolutionary changes that made their hands and feet more like those of ground-dwelling animals. These adaptations allowed pterosaurs to access a wider range of foods, enabling them to become towering titans.
Dr. David Unwin from the University of Leicester explained that as pterosaurs were “freed from the constraints of climbing”, they were able to grow to enormous sizes, with some species becoming true giants. Pterosaurs, close cousins of dinosaurs, lived between 253 to 66 million years ago during the Mesozoic era. They were the first vertebrates to evolve flight but how they became the largest flying animals has long puzzled scientists.
To unravel this mystery, researchers from the University of Leicester’s Centre for Palaeobiology and Biosphere Evolution examined pterosaurs’ hands and feet from different periods of their evolutionary history. In a surprising twist, they found that later pterosaurs were not only adapted to life in the skies but also well-suited for land-dwelling.
Advanced pterosaurs evolved unique features such as hundreds of fine, needle-like teeth for filter-feeding, similar to modern-day flamingos. These adaptations allowed pterosaurs to avoid competition for food from ground-dwelling creatures. The researchers discovered that in early pterosaurs, their hand and foot bones were ideal for tree climbing, resembling those of climbing lizards and birds like woodpeckers.
However, in more advanced pterosaurs, the bone structure in their hands and feet suggested they were better adapted for walking on land. Early pterosaurs had hind limbs connected by a membrane that hindered their mobility on the ground. In contrast, later pterosaurs had separated membranes in their hind limbs, enhancing their ability to move independently.
Lead author Robert Smyth highlighted that the ability of pterosaurs to fly is just one part of their story and understanding how they lived in trees or on the ground provides insights into their roles in ancient ecosystems. This research sheds new light on the evolution of pterosaurs and their journey to becoming the magnificent flying giants of prehistoric times.