2023-08-08 17:09:03
MADRID, 8 Ago. (EUROPA PRESS) –
Contrary to common assumption, turtle shell size is not related to weather conditions. Rather, the evolution of size is linked to its use of the habitat.
This is the conclusion of a new study published in the journal Ecology and Evolution.
With a carapace length of about 100 millimetersThe banded tortoise (Homopus areolatus) is one of the smallest tortoise species that exists today. The record at the other end of the scale is held by the leatherback turtle (Dermochelys coriacea). with a length of up to two meterswhich is found in tropical and subtropical oceans.
“Among fossil turtles, the range of body sizes is even more pronounced,” he says. it’s a statement Dr. Gabriel Ferreira of the Senckenberg Center for Human Evolution and the Paleoenvironment at the University of Tübingen, and continues: “We were curious about how this diversity of shell sizes evolved in the last 200 million years and what factors played a role.” decisive in this”.
To this end, the research team, led by first author Bruna Farina from the Swiss University of Freiburg, compiled the most comprehensive data set on turtle body sizes to date.
The researchers recorded information on carapace length, preferred habitats, and temporal occurrence of the species in geological history for a total of 795 tortoise species. “Previous studies that focused on size evolution often ignored fossil species. Our results also incorporate data from 536 extinct turtle species, which is essential if you want to understand the evolutionary history and physical adaptations of turtles,” adds Ferreira.
The new study shows that the current global climate does not appear to have a significant impact on the body size of the newly studied tortoises. The correlation with paleotemperatures also did not indicate any significant effect on the size of fossil animals, find the studio According to the study, the body size of turtles is determined by the animals’ ecology and habitat preferences, rather than climatic factors.
“The assumption that living organisms tend to increase in body size throughout evolution, known as ‘Cope’s Law’, it cannot be demonstrated in turtles,” explains Ferreira, continuing: “The size spectrum of freshwater species has remained fairly constant over the last 200 million years. In contrast, land and sea turtles show much more pronounced variation.”
According to the team, the variation in body size among turtles can be explained by their ecological diversity and varied habitats. This would allow larger terrestrial species to disperse more easily. In sea turtles, on the other hand, upper and lower limits of body size seem to be related to physiological limitationssuch as thermoregulation or increased lung capacity, and morphological limitations, such as the size of the shell, as well as adaptations to life in open water spaces. It is also possible that the need to go ashore to lay eggs limits the maximum size of sea turtles.the researchers say.
“Our findings are very interesting, considering that body size in other animal groups, such as dinosaurs or crocodiles, is influenced by climatic factors, as the temperature prevailing in the habitat. This underlines the unique nature of turtles.“, concludes Ferreira.
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