TORONTO – US scientists say they have discovered a new species of microscopic animal suspended in a 16-million-year-old piece of amber.
While these tiny creatures, known as tardigrades, have thrived on Earth for more than 500 million years, experts say that the microscopic animals are part of their “ubiquitous ancient lineage” and ability to survive in extreme conditions, including space. Despite this there is almost no fossil record.
Researchers from the New Jersey Institute of Technology and Harvard University have uncovered the third clearest tardigrade fossil ever found, noting that it is the “best-image” ever found.
“The discovery of fossil tardigrades is truly a once-in-a-generation event,” said study senior author and assistant professor at the New Jersey Institute of Technology, Phil Barden. Press release. “Finding any tardigrade fossil remains is an exciting moment where we can see their progress through Earth’s history empirically.”
According to the researchers, this is the first tardigrade fossil found from the Cenozoic Era, 66 million years before Earth’s current geological epoch.
The findings were published Tuesday in the journal Biological Research Proceedings of the Royal Society B.
Measuring just over half a millimeter, the specimen has been identified as a relative of the modern living tardigrade superfamily, Isohypsibioidea.
Scientists have named this never-before-seen species of the tardigrade Paradoriphorbius chronocaribius. According to the study, the name includes the Greek words for the time, “chrono” and “Caribius”, referring to the Dominican region of La Cambre, where it was found.
Mark Maplow, the study’s lead author and Harvard University graduate student, said in the release that the fossil appears similar at first glance to a modern tardigrade, given its “relatively simple external morphology.”
“However, for the first time, we have visualized the internal anatomy of the foregut in a tardigrade fossil and found combinations of characters in this specimen that we no longer see in living organisms,” Maplow said. “Not only does this allow us to place this tardigrade in a new genus, but we can now trace the evolutionary changes this group of organisms experienced over millions of years.”
Tardigrades, or water bears, are known for their unusual appearance and self-preservation abilities. Researchers say the new fossil has captured “micron-level details” of the eight-legged invertebrate’s mouthparts and needle-like claws that are about 20 to 30 times finer than a human hair.
Researchers say the biggest challenge in locating tardigrade fossils is their size.
Barden noted that the new species is only a “faint speck in amber”. According to the study, the amber also trapped other insects, including a flower and three ants.
“In fact, PDO. chronocaribius was originally an inclusion hidden in the corner of an amber piece our lab was studying with three different ant species, and it was not seen for months,” Barden releases. said in.
Barden said the microscopic, non-biomineralized bodies of tardigrades are “uniquely suited” to be preserved in amber, capable of safely enveloping small organisms, such as individual bacteria.
“This particular mode of fossilization helps explain the patchy fossil record,” he explained. “Fossil amber with arthropods trapped inside is known from only 230 million years ago to the present – less than half the history of tardigrades.”
While the new fossil is a major discovery, Barden says the research team is “scratching the surface” to understand living tardigrade communities.
The researchers suggest that the rare fossil may provide new molecular estimates that provide insight into key evolutionary events that have shaped the more than 1,300 species found across the planet today.
“This study provides a reminder that, as little as we may have in the form of tardigrade fossils, we still know very little about the species living on our planet today,” Barden said.