Still looking for that blue jean baby queen, prettiest girl I ever seen....

Get it?I quoted David Essex. The song 'Rock On'? It's a rock? Get it?

I figured, I haven't done a fossil post for a while, so, I'd torture you all again. And so, I present to you, another rock with a dead thing in it.


This particular dead thing is really cool, though. Come with me as I take you an a journey back to the time when life was really starting to get going.

That little guy, (or girl, I have no idea), is an Eurypterid. The example I have, (my personal specimen is pictured), is a small one. It measures about 3 1/2 inches long. It's missing it's left swimming paddle, and the tip of it's telson.

Eurypterids are commonly called Sea Scorpions. That's because they were. Pretty much. Although, their closest living relative is the Horseshoe Crab. They had two appendages that had claws they would use for grabbing prey. They also had two swimming paddles. You can see the one on the right. (the largest appendage)


On the left side of the head, you can see a line of four appendages. The front one is whats left of one of it's claw-arms. The rear three are it's left side walking appendages. (the ones on the right aren't visible, either gone forever, or under the body)

On the right, up near the top of the head, (the cephalon), is what looks like a dark triangle. It's actually a feathery, lace-like appendage that they used to detect prey swimming in the water.

On it's tail, you can see something that's going down into a point, but is broken off. It's the telson. Or, to use a word you'll actually know, it's a stinger. What happened to the tip of it? There is no way of knowing.

This example was taken from a formation in New York that dates back to the Silurian period, about 400 million years ago. (and I thought 45 was old....)

Eurypterids lived From the Ordovician period to the Permian/Triassic extinction event. (460 mya-248 mya) The one I have is pretty common size wise. Most were between 3 inches and a foot long. Although, there were some, like Jaekelopterus. It was about 8 1/2 feet long. And, it was a bad ass!

Eurypterids were predators. They would eat anything. And, they had a nasty trick. They were part time, terrestrial creatures. That means, they could exit the water and live for a time on land. Their breathing system used gills, primarily, but they were external, so they could absorb oxygen on dry land like they could under water. Back when they lived, there weren't too many land based creatures. it's thought they would walk on lad to travel from pool to pool for hunting, or to sometimes lay in ambush to catch something swimming close to shore.


They may have also gone on land to molt. When an arthropod sheds it's exoskeleton, it's very vulnerable until it's new shell starts to harden. Being on land would be a huge advantage for them.

Currently, there are 246 different species of Eurypterids known. The one I have is an Eurypterus remipes, the most common of all the Eurypterid.

I hope you enjoyed a look at this odd creature from way back when, in the long long ago, the before time. I know I enjoyed the excuse to get it out of it's display case to look at it closely again.

I'll see you next tomorrow, same bat time, same bat channel.