Eurypterid fossils on display in the Denver Museum of Science and Nature. Picture courtesy of Tony Martin.

def. Eurypterid:
1. A group of extinct arthropods that were fearsome marine predators of the Paleozoic. There were over 200 different species of eurypterid, and they ranged from very small (less than 20 cm) to very large (greater than 8 feet). Because of their long tail, eurypterids are sometimes called “sea scorpions.” Indeed, they are closely related to today’s scorpions and other arachnids. One species of eurypterid, Eurypterus remipes, is the state fossil of New York.
2. A really, really cool fossil that I one day hope to add to my rock collection.

You can find out much more about eurypterids on wikipedia and Google. You can also buy your very own plush eurypterid here.

A cuddly eurypterid. I hope someone gives me one for Christmas! Picture from: http://www.museumoftheearth.org/store/storeitemdetails.php?pubID=5743.

***Thanks to Liz Johnson for suggesting this week’s word, inspired by my own What to Buy a Geologist for Christmas: 2012 Edition post. Thanks also to Tony Martin for providing the wonderful picture of eurypterid fossils.***