Often the greatest discoveries are made by chance, and it is recent news that a very rare fossil of tardigrade , also known by the nickname of water bear, was found in a perfect state of fossilization inside the amber coming from the La Cumbre region of the Dominican Republic, known for the numerous deposits of this material. This type of amber differs from the Baltic one due to its greater transparency and has always been a privileged place for the discovery of ancient fossils, often found trapped inside.
The tardigrade in question has remained well preserved 16 millions of years in the sticky resin of the tree, which decreed his death, and now that he has been discovered he has quickly become a celebrity within the scientific community. Belonging to the species Paradoryphoribius chronocaribbeus, the small specimen is about half a millimeter long and this is how it appears to the view through the use of a microscope.
Just think, we are faced with the oldest fossil of tardigrade ever identified in the Cenozoic era , the geological age of the Earth that began 66 millions of years ago to end about 1.8 million years ago.
Tardigrades are also known by the nickname of “water bears” due to their bizarre appearance when viewed under a microscope, and are considered almost invincible due to some particular characteristics: they live peacefully in the absence of oxygen and can tolerate the absence of water for 5 years dehydrating, even reaching 30 years when they enter a dormant state. The cold does not pose a great threat, as they can survive for days in temperatures as low as – 200 degrees Celsius. Even high levels of radiation are almost a caress, as are high levels of pressure (they survive even at values 6 times higher than those of the ocean floor). For these reasons they have recently been used also on the ISS for some scientific experiments in microgravity conditions.
The tardigrade discovered in amber was initially mistaken for a small crack, an event not at all rare given the micrometric dimensions, but a closer observation confirmed the suspicions of the researchers as stated by the author of the study, Phil Barden.
“At first I thought it was an artifact in amber, a crack or a crack that closely resembled a tardigrade “
But then the identification of the tiny claws of the animal confirmed all the suspicions and we moved on to a more in-depth analysis. Scientists were able to observe micron-level details such as the invertebrate’s mouthparts and its needle-like claws, 20 – 30 times more thin of a human hair. This fossilized specimen will tell us how tardigrades have changed over time, and apparently we still have a lot to learn about their evolution. The fossil will later be transferred to the American Museum of Natural History.