Fish bones, as well as plant fossils, have helped paleontologists pinpoint the exact time of the horrific catastrophe that wiped out ancient reptiles.
About 66 million years ago, a terrible catastrophe occurred - a huge meteorite crashed into our planet and led to the death of the dinosaurs. But in what month exactly the impact occurred remained a mystery for a long time.
A new study by scientists has shown that dinosaurs died in the summer in June.
Experts have been able to figure out the exact month of the horrific event thanks to the latest evidence obtained from a place called Tanis, located in the Hell Creek Formation in North Dakota.
In this place, researchers were able to find the remains of dinosaurs, early mammals, fish and plants. Remarkably, many of these fossils were found in almost exceptional preservation, some even showing traces of soft tissue.
Tanis was first discovered in 2008 and since then it has attracted the attention of many scientists, in particular paleontologist Robert DePalma from the University of Manchester. In a 2019 study, DePalma and his colleagues found that Tanis captured the moment the asteroid struck. This is evidenced by several factors.
1. The presence of the remains of ancient reptiles that were found in sediments up to the boundary of the Cretaceous and Paleogene periods, and exactly on the boundary at the time of the impact.
2. A layer of molten spherules - small glass balls. When the asteroid hit the globe, it scattered debris and molten globules over thousands of kilometers. In addition to molten spherules in fossil rocks, researchers also found large quantities of them in the skeletons of some fish. Most likely, the fish swallowed the balls falling from above into the rivers.
3. Traces of so-called standing waves, reminiscent of a swing, which usually occur in closed or partially enclosed bodies of water. These waves were formed by a distant impact in Mexico.
In their new study, paleontologists examined the bones of a modern, recently deceased sturgeon. As a result, they found out that there is a layer in the fin bones that can be used to determine the age of the fish. Moreover, judging by the layers, or more precisely, their chemical composition, one can notice the alternation of fresh water in summer and salt water in winter.
Having recorded this fact, experts began studying the remains of the best-preserved fish skeletons of the Cretaceous period. With their help, scientists learned that the meteorite fell during the transition from spring to summer in the northern hemisphere. In other words, the disaster occurred at the turn of May or June.
These results from the paleontologists' analysis coincide with an earlier study that studied fossil plants - water lilies. They also showed that the disaster occurred in early June.
Recall that during their recent study scientists managed to discover the complete skeleton of an ancient ichthyosaur. The remains of a giant reptile were found in England. The length of the "sea dragon" is reached 10 m, and its age is 180 million years.
But in December last yearresearchers stumbled upon a perfectly preserved dinosaur embryo. He was nicknamed "baby Yingliang" and his age ranges from 66 to 72 million years. What struck paleontologists most was the fetal position.
