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Researchers say they have how humans got teeth. The researchers are from Uppsala University in Sweden. They that human teeth "first 400 million years ago". They believe our teeth from an ancient fish called an acanthothoracid. The researchers a fossil of the fish. It was difficult to study because the fish is in rock. The researchers had to use the strongest X-ray machine in the world to it. They used the X-ray machine to "digitally " the fish. The researchers that the fish's teeth were amazingly similar to human teeth. The researchers also said humans and 60,000 species of jawed vertebrates living on Earth today from this fish.

The researchers say the acanthothoracid was one of the earliest jawed vertebrates with teeth ever to . They were very excited at how similar its teeth were to ours. A co-author of the study, Professor Per Ahlberg, said: "These findings our whole understanding of the origin of teeth." He on the similarity to the fish, saying: "Their jawbones those of bony fish and to be directly ancestral to our own. When you at the bathroom mirror in the morning, the teeth that grin back at you can their origins right back to the first jawed vertebrates." Another researcher said: "Nobody to teeth so deep on the evolutionary tree."

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