The exceptional discovery of a dartigrade that lived 230 million years ago

The Dartigrates are well known for their ability Withstand extreme conditions. But, despite their wide global distribution and long evolutionary lineage, fossil forms are very rare. So this is an exceptional finding, the researchers describe in a study published in the journal Processes of the Royal Society b. It was discovered in an amber fragment from the Dominican Republic and dates back to the Miocene (about 16 million years ago), indicating not only a new species but also the first known fossil of the Cenozoic Geographical era Current

So far, only three Dartigrade fossils have been found. The first two, the date Cretaceous High, amber pieces were found in Canada and the United States, and third, primitive and dating Cambrian Found in middle, Siberia. ” The discovery of a dartigrade fossil is a generational phenomenon Says Bill Barton, co-author and biologist at an article at the New Jersey Institute of Technology.

In the absence of microscopic size (described as half a millimeter per fossil) and strongly biodegradable body parts, very few fossil recordings are available to trace the evolutionary lineage of these unusual animals.

Amber is the Subject Suitable for keeping these creatures as small as fragile, but Fossil Amber 230 million years ago ” Or less than half the history of tardigrades », Attested by Bill Barton. It is therefore estimated that the Turgigrades differed from other Panarthropod lineages during the Cambrian period 540 million years ago.

Small nails are 20 to 30 times thinner than hair

⁇ This model is the best detail to date “, Congratulations to the researchers who named the new species Paradoryphoribius chronocaribbeus. Thus we can distinguish between mouth parts and needle-shaped nails that are 20 to 30 times thinner than a hair. ” At first glance, this fossil looks very similar to modern dartigrates because of it Morphology Relatively simple », Notes Mark Mapolo, principal author of the study and holds a doctorate in organic and evolutionary biology from Harvard. This made it possible to associate it with the Isohypsibioidia family, which represents one of the four modern Dartigrade families, and is characterized by their small claws.

However, this species exhibits distinctive morphological characteristics. ” That is, whether Paradoryphoribius chronocaribbeus is a member of a completely extinct posterior genus or whether it is related to a species is not yet known. tardigrades alive And not yet discovered “, Say the authors. New images are on display in the area Invertebrates From the American Museum of Natural History in New York.