Four specimens of a 100-million-year old spider-like arachnid were found preserved in amber, according to research published Monday in the journal Nature Ecology and Evolution.

Why it matters: "It throws up a combination of characters that initially seems alien to an arachnologist," paleobiologist Greg Edgecombe told the New York Times' Nicholas St. Fleur. It shows how diverse arachnids once were, and "presents some intriguing hints at how they evolved," writes Sarah Kaplan for The Washington Post.

The arachnid has the head of a spider, but the back-end looks like a scorpion's with legs. Like a scorpion, it has a long, whip-like tail. But the researchers think the tail didn't sting — it was probably more like an antenna. The not-spider also has spinerettes, similar to those modern spiders use to make silk.

Sound smart: The spiders' scientific name is Chimerarachne yingi. The chimera is a mythological monster with a lion's head, goat's body, and snake's tail. Arachne is the greek root for the word 'spider.' It's a fitting name for an animal that looks like a spiders' head with something else attached to the back.