The evolutionary adaptations that allowed ancient pterosaurs to grow to enormous sizes have been identified for the first time by researchers at the University of Leicester. These adaptations included the ability to efficiently walk on the ground, which played a crucial role in determining the size of the largest flying animals. Pterosaurs, the first true flying vertebrates, were not only adapted to life in the skies but also had a wide range of terrestrial lifestyles, from tree-climbing in early species to more ground-based lifestyles in later ones.
A new study published in Current Biology examined the hands and feet of pterosaurs from around the world and across their evolutionary history. The researchers found a surprising level of variation similar to that seen in living birds, indicating that pterosaurs had a diverse range of terrestrial adaptations. Early pterosaurs were highly specialized for climbing, resembling climbing lizards and birds like woodpeckers. However, a major evolutionary shift occurred during the Middle Jurassic period, leading to adaptations for ground-based movement that allowed some pterosaurs to evolve into giants with wingspans of up to 10 meters.
Global lead author Robert Smyth explained that the shift towards ground-based movement opened up new ecological opportunities for pterosaurs, leading to a variety of feeding strategies. This shift allowed pterosaurs to evolve to enormous sizes by freeing them from the constraints of climbing. Co-author Dr. David Unwin added that changes to the hind limbs of pterosaurs greatly improved their mobility on the ground, enabling them to reach gigantic sizes in the Mesozoic era. The details of the hands and feet of pterosaurs revealed a clear evolutionary pattern, with early species adapted for climbing and later species adapted for walking.
The researchers emphasized the importance of studying all aspects of pterosaur locomotion, not just flight, to fully understand their evolution. Pterosaurs were able to avoid competition with existing ground-dwelling animals by exploiting ecological niches that required both flying and walking abilities. This led to the development of unique feeding strategies, such as hundreds of fine, needle-like teeth for filter-feeding. This feeding method, similar to that of modern flamingos, emerged at least 120 million years before the evolution of flamingos, highlighting the diverse and innovative ways in which pterosaurs adapted to their environment.
The study shed light on the incredible diversity of pterosaurs and their varied lifestyles beyond flying. By exploring how pterosaurs lived in trees or on the ground, researchers can gain a better understanding of the roles these ancient creatures played in ancient ecosystems. Understanding the evolutionary adaptations of pterosaurs provides insights into how they were able to reach such enormous sizes and thrive in a competitive environment filled with other prehistoric animals. Ultimately, the study highlights the importance of looking beyond flight when studying ancient flying animals like pterosaurs.
