Scorpions are ancient. They have been on Earth some 435 million years.

Some of the older creatures — the ancestors of modern scorpions — grew to a length of up to 4 feet. Some of today’s scorpions can kill humans, while others rarely sting or have venom that doesn’t affect humans or other mammals.

Still, mysteries remain.

Lauren Esposito, curator of arachnology at the California Academy of Sciences; Lorenzo Prendini of the American Museum of Natural History, and other scorpion specialists this summer reported the identification of three new species of club-tailed scorpions.

They collected scorpions in the field — carefully — and pored through museum specimens around the world, looking at DNA and physical traits. The new species they identified live in tropical areas of the Americas. Some can make a hiss or rattling sound to warn off potential predators.

Among Esposito’s favorite facts about the creatures: They give birth to live young. But you may have heard that the smallest scorpions are the most venomous: That is a myth. Esposito said a clue that is more helpful is that the scorpions with the biggest claws are often the least venomous.

New York Times