A group of ancient amphibians called temnospondyls evolved stiffer spinal columns to adapt to aquatic life, contrary to previous hypotheses, according to a study published June 9, 2021 in the open-access journal PLOS ONE by Aja Mia Carter of the University of Pennsylvania and colleagues.
Temnospondyls are an extinct group of amphibians, and they were some of the earliest land-dwelling vertebrates, living in terrestrial, aquatic, and semi-aquatic habitats. They therefore provide valuable information on how early vertebrates adapted to the transition from water to land. In this study, Carter and colleagues provide new data on how temnospondyl backbones adapted to changes in their environment and locomotion.
The researchers collected measurements on fossil vertebrae of more than 40 species of temnospondyls. These species ranged in size from half a meter long to six meters, ranged in geologic age from the Carboniferous Period to the Cretaceous, and lived in a diverse array of habitats from arid upland to ocean.
The researchers found that the lower portion of vertebra (an element called the intercentrum), the shape of which determines the flexibility of the spinal column, varied most in correlation with species’ habitat. More aquatic species had more rigid backbones. Comparing species across the evolutionary history of this group suggests that the earliest temnospondyls were terrestrial, and their descendants transitioned to the water multiple times, with corresponding changes in their vertebral shape.
These results are in contrast to previous hypotheses that increased spinal rigidity was important for terrestrial locomotion. These findings additionally indicate that the intercentrum is correlates more with the environment than than the upper portion of vertebrae (a region called the neural arch). The difference between the two parts has never before been investigated and there are noprevious interpretations. Further investigation will enhance our understanding of how animals adapt during the transition between swimming and walking lifestyles, including our oldest land-dwelling ancestors.
The authors add: “We demonstrated that the temnospondyls, a group of ancient, diverse, stem amphibians, repeatedly converge on vertebral shapes upon invasion and reinvasions of new habitats. We overturn previous hypotheses suggesting that rigidity was necessary for terrestrial locomotion in crucial vertebral elements in all temnospondyl taxa.”
The Evolution of Amphibians and the Origin of Vertebrae
Amphibians are fascinating creatures that have been around for over 360 million years. They were the first vertebrates to emerge from the water and conquer the land. The evolution of amphibians is a complex process involving many factors, including vertebrae development. In this article, we will explore how amphibians got their vertebrae and what this means for their evolution.
The Origin of Vertebrates
Vertebrates are animals that have a backbone or spinal column. The origin of vertebrates is a topic that has puzzled scientists for many years. The earliest vertebrates were jawless fish that lived over 500 million years ago. These fish had a notochord, a flexible rod that provides support and allows for movement. Over time, this notochord evolved into the backbone or spinal column that we see in modern-day vertebrates.
The Emergence of Amphibians
Amphibians are a group of vertebrates that include frogs, toads, salamanders, and newts. They evolved from fish-like ancestors that lived in water. One of the key adaptations that allowed amphibians to move from water to land was the development of legs. The earliest amphibians had four legs and a short tail, which allowed them to move around on land. However, they still had to return to the water to lay their eggs, as they did not yet have the ability to lay them on land.
The Evolution of Vertebrae in Amphibians
The evolution of vertebrae in amphibians is a fascinating topic studied extensively by scientists. The first amphibians had a notochord, which provided support and allowed for movement, but they did not yet have a true backbone or spinal column. Over time, the notochord evolved into the spine in modern-day amphibians. The development of a true backbone allowed for more incredible support and protection of the spinal cord, which is essential for movement and survival.
The Importance of Vertebrae in Amphibians
Vertebrae are essential for the survival and movement of amphibians. They provide support and protection for the spinal cord, which sends signals to the muscles and allows for movement. Without a backbone, amphibians would not be able to move around on land or protect their spinal cord from injury
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