Discovered in Catalonia the oldest fossil of a flying squirrel
Discovered in Catalonia the oldest fossil of a flying squirrel
At the Can Mata Landfill (Catalonia, Spain), an international team of scientists has recovered more than 80 skeletal bones, including a skull and several elements of the anterior and posterior limbs, of a flying squirrel, belonging to the species Myopetaurista neogrivensis. The analyzes, which are published in the eLife magazine, confirm that she was a planner and that she lived 11.6 million years ago.
Flying squirrels have a unique and unmistakable morphology of the wrist bones, which are modified to hold and unfold the patagium, the name given to the skin membrane they use to fly. Squirrels actually plan using this membrane. Thanks to this system they can travel up to 150 meters from one tree to another.
Miopetaurista was a flying squirrel of very large size. The researchers estimate that it should weigh between 1.1 and 1.6 kilos, comparable to most species of giant squirrels today.
"We have to imagine an animal almost one meter long including the long tail and that, with the extremities extended, could have a wingspan of about 40 centimeters", explains Isaac Casanovas, the researcher of the Catalan Institute of Paleontology Miquel Crusafont (ICP) who leads the study. The bones are so large that initially the scientists thought they had found the remains of a primate.
The large number of pieces recovered has allowed to generate a three-dimensional model of the skeleton. "From computerized tomographies (CT scans) of the skull and multiple photographs we elaborate models of the different bones to obtain the 3D model", point out Josep Fortuny (ICP) and Óscar Sanisidro, of the University of Kansas (USA), coauthors of the article . "To fill in the gaps in the missing elements we rely on the anatomy of the current giant flying squirrel," they clarify.
Recreation of Miopetaurista neogrivensis. (Photo: O. Sanisidro)
High resolution 3D models have been made available to the scientific community, so they can be downloaded and your skeleton can even be printed using a 3D printer.
The phylogenetic analyzes carried out in this study have combined for the first time morphometric data of extinct and current species as well as DNA sequences of the current species.
"The results show that this fossil squirrel is closely related to the giant flying squirrels of the genus Petaurista, widely distributed throughout South Asia," says Joan Garcia-Porta, a researcher at the Center for Ecological Research and Forestry Applications (CREAF, UAB) and responsible for coordinating phylogenetic analyzes.
"In fact, the skeleton of the current giant flying squirrel is very similar to that of Miopetaurista, to such an extent that bones such as the femur or the humerus are practically indistinguishable," Casanovas says.
Flying squirrels evolved from arboreal forms such as the common squirrel, but there is no agreement about when this separation occurred. "The molecular studies that had been done previously pointed to about 23 million years ago, but in the fossil record some remains that could belong to flying squirrels have been found and they are 36 million years old," says Casanovas.
"What happens is that these ancient remains are mainly teeth and it is difficult to attribute them with certainty to a flying squirrel," says the researcher. In this research, experts estimate that the separation took place between 31 and 25 million years ago. Therefore, the oldest fossils that have been found do not correspond to species of flying squirrels.
Among mammals, only bats present a propelled flight, but several groups that are not closely related to each other have developed membranes to plan. These include flying lemurs or some marsupials such as sugar petauros. However, flying squirrels are the only gliding mammals that have had evolutionary success, as up to 52 different species are known and widely distributed in Eurasia and North America. However, the origins of its evolutionary history are still quite unknown.
The study of the mammals of the Landfill of Can Mata, where more than 80 species have been found, makes it possible to deduce the presence of a closed forest and a humid subtropical climate. The fact that beavers and mouse deer have been found indicates the occasional presence of areas with permanent water bodies. Primates, some dormice and flying squirrels would indicate the presence of dense forest environments. (Source: Institut Català de Paleontologia Miquel Crusafont (ICP))
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SOURCE LINK ERESVIRAL.COM https://www.beviral.online
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