TY - JOUR
T1 - Hand and foot morphology maps invasion of terrestrial environments by pterosaurs in the mid-Mesozoic
AU - Smyth, Robert S.H.
AU - Breithaupt, Brent H.
AU - Butler, Richard J.
AU - Falkingham, Peter L.
AU - Unwin, David M.
PY - 2024/10/4
Y1 - 2024/10/4
N2 - Pterosaurs, the first true flying vertebrates, played a crucial role in Mesozoic terrestrial ecosystems. However, our understanding of their ability to move around on the ground and, more broadly, their terrestrial paleoecology remains limited. Here, we demonstrate an unexpectedly high degree of variation in the hands and feet of pterosaurs, comparable with that observed in extant birds. This suggests that pterosaurs were adapted to a remarkably broad range of non-aerial locomotor ecologies. Small, early, long-tailed pterosaurs (non-pterodactyliforms) exhibit extreme modifications in their hand and foot proportions indicative of climbing lifestyles. By contrast, the hands and feet of later, short-tailed pterosaurs (pterodactyliforms) typically exhibit morphologies consistent with more ground-based locomotor ecologies. These changes in proportions correlate with other modifications to pterosaur anatomy, critically, the separation along the midline of the flight membrane (cruropatagium) that linked the hindlimbs, enabling a much more effective locomotory ability on the ground. Together, these changes map a significant event in tetrapod evolution: a mid-Mesozoic colonization of terrestrial environments by short-tailed pterosaurs. This transition to predominantly ground-based locomotor ecologies did not occur as a single event coinciding with the origin of short-tailed forms but evolved independently within each of the four principal radiations: euctenochasmatians, ornithocheiroids, dsungaripteroids, and azhdarchoids. Invasion of terrestrial environments by pterosaurs facilitated the evolution of a wide range of novel feeding ecologies, while the freedom from limitations imposed by climbing permitted an increase in body size, ultimately enabling the evolution of gigantism in multiple lineages.
AB - Pterosaurs, the first true flying vertebrates, played a crucial role in Mesozoic terrestrial ecosystems. However, our understanding of their ability to move around on the ground and, more broadly, their terrestrial paleoecology remains limited. Here, we demonstrate an unexpectedly high degree of variation in the hands and feet of pterosaurs, comparable with that observed in extant birds. This suggests that pterosaurs were adapted to a remarkably broad range of non-aerial locomotor ecologies. Small, early, long-tailed pterosaurs (non-pterodactyliforms) exhibit extreme modifications in their hand and foot proportions indicative of climbing lifestyles. By contrast, the hands and feet of later, short-tailed pterosaurs (pterodactyliforms) typically exhibit morphologies consistent with more ground-based locomotor ecologies. These changes in proportions correlate with other modifications to pterosaur anatomy, critically, the separation along the midline of the flight membrane (cruropatagium) that linked the hindlimbs, enabling a much more effective locomotory ability on the ground. Together, these changes map a significant event in tetrapod evolution: a mid-Mesozoic colonization of terrestrial environments by short-tailed pterosaurs. This transition to predominantly ground-based locomotor ecologies did not occur as a single event coinciding with the origin of short-tailed forms but evolved independently within each of the four principal radiations: euctenochasmatians, ornithocheiroids, dsungaripteroids, and azhdarchoids. Invasion of terrestrial environments by pterosaurs facilitated the evolution of a wide range of novel feeding ecologies, while the freedom from limitations imposed by climbing permitted an increase in body size, ultimately enabling the evolution of gigantism in multiple lineages.
KW - Mesozoic
KW - Pterosauria
KW - adaptive radiation
KW - manus
KW - pes
KW - ecomorphology
KW - locomotor ecology
KW - arboreal
KW - scansorial
KW - terrestrial
U2 - 10.1016/j.cub.2024.09.014
DO - 10.1016/j.cub.2024.09.014
M3 - Article
SN - 0960-9822
JO - Current Biology
JF - Current Biology
ER -