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

Purhepecha oak (Quercus purhepecha), new species of shrub oak endemic to the state of Michoacán, Mexico

NEWS - In Mexico, several Quercus shrubby species are taxonomically very problematic including 8 taxa with similar characteristics. Now researchers report the purhepecha oak ( Quercus purhepecha De Luna-Bonilla, S. Valencia & Coombes sp. nov.) as a new tomentose shrubby white oak species with a distribution only in the Cuitzeo basin in the Trans-Mexican Volcanic Belt (TMVB). Quercus Linnaeus (1753) subdivided into 2 subgenera and 8 sections of which section Quercus (white oaks) has the widest distribution in the Americas, Asia and Europe. This section is very diverse in Mexico and Central America with phylogenomic evidence indicating recent and accelerated speciation in these regions. The number of shrubby oak species in Mexico is still uncertain. De Luna-Bonilla of the Universidad Nacional Autónoma de México and colleagues found at least 3 taxa in the TMVB, specifically Quercus frutex Trelease (1924), Quercus microphylla Née (1801) and Quercus repanda Bonpland (1809). In 2016,...
Read more

Javan mocca or Javan slender caesar (Amanita javanica)

OPINION - Javan mocca or Javan slender caesar ( Amanita javanica ) is a mysterious fungus species and has been enigmatic since it was first reported by Boedijn in 1951 and after that no explanation or reporting of specimens is believed to be the same as expected. Boedijn (1951) described A. javanica which grew on Java island as having the characteristics covered in the Amanita genus. Corner and Bas in 1962 tried to describe Javan mocca and all species in Amanita based on specimens in Singapore. Over time some reports say that they have found A. javanica specimens in other Southeast Asia including also China, Japan, India and Nepal. But there is no definitive knowledge and many doubt whether the specimen is the same as described by Boedijn (1951). I was fortunate to have seen this species one afternoon and soon I took out a camera for some shots. In fact, I've only met this mushroom species once. Javan mocca is an endangered species and I have never seen in my experience in...
Read more

Tekijem (Cyperus cyperoides)

Tekijem ( Cyperus cyperoides ) is a plant species in Cyperaceae, annual grasses that grow in seasonal wetlands, open or shaded fields, swamps, ponds, rice fields, roadsides, open forests, secondary forests and shrubs at altitudes up to 1,800 m in the tropics. C. cyperoides has an upright, triangular shape, 20-75 cm tall from a very short rhizome and has no stolon. The lanceolate-shaped leaves are narrow and long, the tips are pointed, slippery, shiny, green and grow at the bottom and at the top of the stem. The terminal flower appears on the tip of the stem, cylindrical spiklet shaped and green. Each stem has two to seven flowers, each of which has a short or long stem that grows at the end of the stem together with the leaves. Tekijem grows solitary or in small groups at a distance. Propagating using vegetative and generative methods using seeds. At least three sub-species are Cyperus cyperoides cyperoides , Cyperus cyperoides flavus and Cyperus cyperoides pseudoflavus . Th...
Read more