Recently the scientists have made a startling discovery of 16 million-year-old amber, with an extremely rare fossil of a tardigrade suspended within. The unseen species of a tardigrade is a stubby aquatic critter, which rarely can be found in the record of fossils.
What is a Tardigrade?
The modern version of tardigrade, as we know it, is also known as moss piglets or water bears. They can be found in any environment with even the slightest amount of liquid water. Starting from the depths of the ocean to terrestrial moss coating thin water films, these tiny creatures are literally everywhere! They have a surprising survival skill. They expel the most amount of water from their bodies, which drastically slow down their metabolism. As a result, tardigrades enter an almost suspended animated state, in which they can endure extreme pressure, temperature, and even radiation.
Why are the Tardigrade Fossils Rare?
Tardigrades are almost impossible to destroy while alive. Their very small size and lack of hard tissue results in a very low fossil formation. To be exact, only three tardigrade fossils have been discovered so far. Two species were found in Canada and New Jersey, and have been given proper names. But the other one, which was found in West Siberia, still remains unnamed.
What is the Recent Discovery?
Recently the scientists have introduced a new species of tardigrade, which was discovered in the Dominican Republic. The fossil dates back to the Miocene epoch, which means 23 million to 5.3 million years ago. The fossil is very well-preserved within the amber, in which it was discovered. For this reason, the scientist team was even able to place the particular type of species within the tardigrade life tree. The name of this newfound 0.6 millimeters long tiny species is ‘Paradoryphoribius chronocaribbeus’.
New Evidence Suggests That Dinosaur-Killing Asteroid Most Likely Struck in Spring
New evidence has come to light about the asteroid that changed the course of Earth forever. Scientists have now identified that the Chicxulub asteroid, which ended dinosaur species on this planet, hit the surface in the spring in the Northern Hemisphere and autumn for the Southern Hemisphere. Read on to find out more about one of the most momentous impact disasters in Earth’s history and the season of its appearance.
Struck in Spring
The clues leading to this conclusion were found in the growth patterns preserved in the fossil bones of filter-feeding sturgeons and paddlefishes. These growth patterns indicate seasons similar to rings in tree trunks. Further evidence was found in the gills, where the impact debris lodged suggested it died instantly. A particular fish was also analyzed for carbon isotopes to determine how much zooplankton had been ingested. This information was useful as the feeding seasons peak during the spring and summer. Director of Smithsonian’s National Museum of Natural History Kirk Johnson has cast doubts on the importance of these conclusions as there was very little seasonality in the Cretaceous period.
These fossils were gathered at Tanis in North Dakota, a late cretaceous deposit. The 66 million-year-old asteroid was responsible for not only ending the reign of dinosaurs on Earth, but also annihilating more than 76% of species. The Northwest Hemisphere species suffered a devastating blow as springtime is a crucial period for reproduction. Researchers have commented that this could be the reason why a faster recovery has been observed in some of the Southern Hemisphere species. Even though Kirk Johnson questions the validity of seasons in this discovery, he has stated that future research could test these ideas with Tanis serving as a reference. He also commented that this discovery opened avenues that had not been considered before.