Paleontologists in the US have discovered traces of two species of sturgeon 66 million years old, creatures that lived and died at the same time as the dinosaurs, preserved in the form of fossils with high detail.The intact fossils of two ancient fish species, with one of which is known as the “fish from hell” have just been discovered in the US.
As a result, they discovered traces of two species of sturgeon 66 million years old, creatures that lived and died at the same time as the dinosaurs, preserved in fossil form with extremely high detail. Their work was published in the Journal of Paleontology in early October.
Accordingly, the team of archaeologists found the fossils at a site called “Tanis.” Tanis is part of the famous Hell Creek Formation and it runs through parts of Montana, South Dakota, North Dakota, and Wyoming.
Tanis was once home to a large and deep river that supplied water to the now arid West Inland Sea Route. This sea route extends from the Gulf of Mexico to the Arctic Ocean. But on a fateful day 66 million years ago, Tanis became a mass grave for thousands of ancient freshwater fish. They were burned and buried in place in the blink of an eye after an asteroid crashed to Earth and wiped out the dinosaurs.
Almost all of the animal’s outer coverings are preserved intact and perfectly in fossils. These specimens help fill an important gap in the North American fossil record, which lacks many late Cretaceous species. “They have a lot of similarities with modern sturgeon, but still have their own characteristics,” said Grande.The researchers named one of the newly found fish species acipenser praeparatorum (“acipenser” means “sturgeon” in Latin, and “praeparatorum” means “get ready,” in honor of the group). prepared the fossils before the study took place.The other species was named acipenser amnisinferos, meaning “sturgeon from hell’s creek.”
Both fish species are now extinct. However, according to study co-author Eric Hilton, a biologist at the Virginia Institute of Marine Science, they share many similarities with modern sturgeon native to East Asia and Europe, not northern sturgeon. America. “They have a thick, hard outer shell that protects the inner soft tissues from the impact of big waves, or strong river currents,” says Hilton, adding that the sturgeon’s preference for areas of high concentration of water. Low oxygen levels also seem to help their fossils better preserved.
However, for the sturgeon in Tanis, the amount of oxygen in the water was less or less important on the day they died. All were victims of a large tsunami that formed when the asteroid hit the Earth, carrying millions of tons of rock and burying them almost immediately.
In addition to the two newly discovered species of sturgeon, the river in Tanis is teeming with paddlefish, bowfin fish, rockfish, various insects and an aquatic reptile known as the lizard mosasaurus. Archaeologists believe that there are still many other species that we do not know yet lying dormant in the sediments here, waiting for the day to be unearthed.
“The new discovery is amazing. But it’s just the tip of the iceberg,” said Hilton.
