Fossilized dinosaur bones contain fragments of rock from the impact is not a piece of evidence supporting the idea that an impact caused the mass extinction that occurred 65 million years ago.
An event can be called a mass extinction when
More than 75 percent of living species died. The last mass extinction occurred about 65 million years ago which wiped out the dinosaurs.
Until now, scientists around the world are still trying to find out what caused the mass extinction. But the cause of the extinction is known to have occurred due to the impact of an asteroid to Earth's volcanic activity.
Mass extinctions can also occur due to changes in Earth's temperature causing decreased oxygen levels.
Joe Wood, a senior scientist at the Chesapeake Bay Foundation, explained that climate change is increasing water temperatures and threatening the lives of several species.
Similar to the first mass extinction, animals that were sedentary or moved little were the animals most vulnerable to extinction. In fact, according to research, only about 30 percent of the 82 species of shellfish in Virginia, USA are considered stable. Six species of shellfish are considered threatened or endangered.
Learn more about mass extinction at https://brainly.com/question/11872946.
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