Skip to main content

Hand and foot morphology maps invasion of terrestrial environments by pterosaurs in the mid-Mesozoic

Hand and foot morphology maps invasion of terrestrial environments by pterosaurs in the mid-Mesozoic

NEWS - Pterosaurs, the first true flying vertebrates, played a significant role in Mesozoic terrestrial ecosystems from about 252–66 million years ago. However, our understanding of their ability to move on land more broadly and their terrestrial paleoecology is limited.

The researchers show a remarkably high degree of variation in pterosaur hands and feet, comparable to that observed in birds today, suggesting that pterosaurs adapted to a wide range of non-aerial locomotor ecologies throughout history.

Early small-bodied, long-tailed (non-pterodactyliform) pterosaurs exhibited extreme modifications in hand and foot proportions indicative of a climbing lifestyle. In contrast, the hands and feet of short-tailed (pterodactyliform) pterosaurs typically exhibit morphology consistent with a more terrestrial locomotor ecology.

"Early pterosaurs were highly specialised for climbing with modifications to their hands and feet, similar to today's climbing lizards and woodpeckers. Holding on to a vertical surface using the fingertips for long periods of time is a difficult task, much easier for small, light animals," says Robert Smyth of the University of Leicester.

This change in proportions correlates with other modifications to pterosaur anatomy, in particular, the separation along the midline of the flight membrane (cruropatagium) that connected the hind limbs and enabled much more effective locomotory abilities on the ground.

Together, these changes map out a key event in tetrapod evolution in the mid-Mesozoic colonisation of terrestrial environments by short-tailed pterosaurs.

"The hind limbs connected by a flight membrane would have constrained walking and running in early pterosaurs. In more advanced pterosaurs, this membrane separated along the midline allowing each hind limb to move independently," says David Unwin of the University of Leicester.

"This was a major innovation that, combined with changes to their hands and feet, greatly increased the mobility of pterosaurs on land. Freed from the constraints of climbing, these later pterosaurs could grow to enormous sizes, with some species becoming true giants in the Mesozoic," says Unwin.

This transition to a predominantly land-based locomotory ecology did not occur as a single event coinciding with the origin of short-tailed forms, but evolved independently in each of four major radiations: euctenochasmatians, ornithocheiroids, dsungaripteroids and azhdarchoids.

The invasion of terrestrial environments by pterosaurs facilitated the evolution of a wide range of new feeding ecologies, while freedom from the constraints imposed by climbing allowed the increase in body size that ultimately enabled the evolution of gigantism in a range of lineages.

"This finding underscores the need to study all aspects of pterosaurs, not just flight. Pterosaur flight is only one part of their story. By studying how they lived in trees and on the ground, we can begin to understand the role they played in ancient ecosystems," Smyth said.

Original research

Smyth, Robert S.H. et al. (2024). Hand and foot morphology maps invasion of terrestrial environments by pterosaurs in the mid-Mesozoic. Current Biology, DOI:10.1016/j.cub.2024.09.014

Dlium theDlium
Labels:

Popular Posts

Lolot (Piper sarmentosum)

Lolot pepper ( Piper sarmentosum ) is a species of plant in Piperaceae, perennial herb, erect or lodging, creeping rhizome, up to 120 cm long, branched, enlarged branches, cylindrical stems, brown or green, often grooved, growing on the forest floor and shade. P. sarmentosum has leaf stalks up to 15 cm long, up to 13 cm wide, green, alternately arranged, heart-shaped, pointed tips and flat margins. The leaves have 5 main veins from the base of the blade, linear and slightly curved to the tip, glands on the upper surface and many fine pinnate veins. The upper side is shiny green, the lower side is pale green. The flowers are white. The fruit grows in the upper armpit of the leaf, is slightly oval and green. The leaves are used as a medicine for asthma, malaria, stomach ache, tinea versicolor, toothache, difficulty urinating, aches and pains, maintaining stamina, antibacterial, antimicrobial, antioxidant, and so on. TAXON Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiosperma...
Read more

Red lip (Syzygium myrtifolium)

Pucuk merah or daun pucuk merah or red lip ( Syzygium myrtifolium ) is a plant species in the Myrtaceae, a medium tree with a cylindrical trunk and produces cambium, up to 5 meters high, bark rough and light brown, many branches and strong roots. S. myrtifolium has oval-shaped leaves, pointed tip and base, up to 7 cm long, up to 2 cm wide, a vein in the middle, flat margins, shiny surface, bright red leaf buds and will turn green over time. The flowers are compound and arranged in panicles. The flowers bloom with a stigma in the center and are white. The fruit is round and up to 1 cm in diameter, the middle of the upper surface has a depression and is shiny black when ripe. This species grows in forests, agricultural land, roadsides and abandoned lands. This tree has a root structure that goes deep into the ground and is sturdy so it is often used to rehabilitate land, prevent landslides and store water reserves. This tree has a greater ability to absorb CO2 than other types of pla...
Read more

Yellow garden spider (Argiope appensa)

Yellow garden spider ( Argiope appensa ) is a species of spider in Araneidae that lives on the coast to forests on islands in the western Pacific Ocean. Black and yellow females are striking and have a length of 5.1-6.4 cm including long legs, while males are brown and have a length of about 1.9 cm. A. appensa lives on cliffs in the hills at 600 m above sea level in Kewu plain to rice fields in the lowlands. They make nests at a height of 1.5 meters from the ground between teak ( Tectona grandis ), sonokeling ( Dalbergia latifolia ), sonosiso ( Dalbergia sissoo ), crown flower ( Calotropis gigantea ) and various grasses. Yellow garden spiders grow in large sizes, but are not toxic to humans. Advanced builds ball-shaped nets and most of them make stabilizers which are zigzag-shaped lines in nets made of thicker bands. This species spends more time in stationary and sits in the middle of the net with its head down to wait for insects to be entangled in fine silk thread. Unli...
Read more