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Ancient Hellfish Killed By Dinosaur Asteroid Discovered In North Dakota

Scientists have discovered the fossils of two new species of sturgeon in North Dakota’s Hell Creek Formation, which were likely buried when the dinosaur-ending asteroid Chicxulub hit Earth.

The discovery sheds light on the history of freshwater fish in North America during the late Cretaceous, which is poorly represented in the fossil record.

It also indicates that the massive effects of asteroid Chicxulub, which hit the Yucatan coast in southeastern Mexico, were felt as far away as North Dakota.

The Hell Creek Formation is a rock formation that covers parts of North Dakota, South Dakota, Montana and Wyoming, known to contain many fossils from the Cretaceous period, which lasted from 145.5 million to 65.5 million years ago and ended with the extinction of the dinosaurs.

Fossils found there include the remains of plants, dinosaurs and small mammals from that period, including early primates, according to Encyclopedia Britannica.

Within the Hell Creek Formation is the Tanis site, which contains a large number of well-preserved fish fossils and is thought to have formed immediately after the Chicxulub impact.

In a study published on October 3 in Journal of Paleontologytwo researchers, Lance Grande, curator of the Negaunee Distinguished Service at the Field Museum in Chicago, and Eric Hilton, a professor at the Virginia Institute of Marine Science, described four sturgeon fossils of two species that were found at the site and have been studied . for several years.

Unlike most known sturgeon fossils from the Cretaceous period, which are represented only by poorly preserved bone fragments or partial skeletons, the four found at the Tanis site are well preserved and consist of skulls and other connected bones.

Sturgeons are a type of fish that have been around for 200 million years and are sometimes referred to as “living fossils”. The sturgeon family Acipenseridae and family Polyodontidae are the only surviving families of Acipenseriformes, a group of ray-finned fishes. As such, the sturgeon family Acipenseridae has been the subject of substantial interest.

“The fish we described were so well preserved that they were probably buried alive or at least immediately after death,” Grande said. Pleasemynews. Therefore, the bones are all still articulated with each other in the fossil specimens.

“The asteroid may have had something to do with it, as the cataclysmic burial may have been the result of a huge tidal wave resulting from the impact. Some scientists have even reported remnants of the actual impact of the asteroid preserved in the gill regions of some specimens.

The two species of sturgeon identified from the fossils were named Acipenser praeparatorum, “acipenser” meaning sturgeon and “praeparatorum” meaning prepare, and “Acipenser amnisinferos”, meaning Hell’s Creek sturgeon, Live Science reported.

Grande said the fossils add to our understanding of freshwater fish just before the Great Dinosaur Extinction, which are not well represented in the fossil record.

“This may be due to an initial lack of fossilization of freshwater sediments in North America, or it may be due to their erosion where they occurred over the past 65 million years,” Grande said. . “And with fish, if the sediment isn’t preserved, neither was the fish that died there.”

The expert added that sturgeon fossils also indicate that at the time of the asteroid impact, “massive effects were felt as far north as North Dakota.”

The asteroid that killed the dinosaurs is thought to have destroyed around 75% of all species living on Earth at the time.

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