EURYPTERID "CLAW"

[TOM BUCKLEY]

I've often wondered as to the purpose of the tiny "claw" at the very tip of a eurypterid's swimming paddle. It's really very small and I can't imagine what it would be used for. It's not an anomaly as  quite a few genera have them. Below are couple of pictures of one of my specimens, and just so you don't think me crazy and seeing things, there is also an illustration showing the feature. Any comments would be welcome.

 

Tom

[grandpa]

8 minutes ago, TOM BUCKLEY said:

"claw" at the very tip

Why Grandma, you have a claw at the tip of your paddle.

 

The better with which to pick my nose, my dear.

[TOM BUCKLEY]

22 minutes ago, grandpa said:

Why Grandma, you have a claw at the tip of your paddle.

 

The better with which to pick my nose, my dear.

 

Do Eurypterids even have noses?

Tom

 

ps. You're from Texas, aren't you. 

[fossilcrazy]

Hi Tom, I was revisiting some pictures of Eurypterids in my area. I found the different species have the same or different tips on the swim paddle appendage. See drawing. It is possible different forms aid in molting, or function to protect the paddle (like fingernails protect our fingers), or they could be evolution driven by the environment like inhabiting muddy bottoms,  or flora filled sea floors. All the "legs" have differences made to suit the species. We can only guess exactly why they are the way they are. Our best efforts to "know", is to compare similar extinct organisms to living ones.

[TOM BUCKLEY]

Good points. I was always intrigued by the idea that they were miniature claws. Notice, on the drawings, they are shown closed, while in the photos of actual specimens, they appear open. This always indicated to me that they must have opened and closed for a reason. What could that have been for such a tiny device? I guess we'll never know until someone is nipped by a Eurypterid while walking in the shallows.

 

Tom

[Adam86cucv]

For eating tiny sandwiches.  Lol. 

[TOM BUCKLEY]

25 minutes ago, Adam86cucv said:

For eating tiny sandwiches.  Lol. 

 

[Al Tahan]

I get this feeling like the tips of the paddles were used to push off or around the sea floor. This would only be useful on a decently firm bottom however. Or it could have been used to help navigate coral or harder bottoms and those little “claw” could have been little grippy contact points for the Eurypterid to push and move along. I Imagine it would grip and push well off of a craggy rough surface. 
 

of course....all speculation here lol. 
 

these eurypterid paddles have some little movements (closing/opening/rotating)we don’t realize are there unless you have enough specimens to stare at. I think the paddles on a Eurypterids had more than 1 job making it a tough one to interpret 

[Al Tahan]

Here are a few examples

 

Eurypterus lacustrus (williamsville fm)

 

Eurypterus laculatus (fiddlers green) 

 

Eurypterus remipes (fiddlers green) 

 

Each demonstrate a slightly different position as well. Bear with me on thee made up terms....they show an “Open” “neutral” and “closed” look. 

 

lots of moving parts on these fellas 

[TOM BUCKLEY]

Interesting idea. Your photos clearly show that the ends of the paddles were more like serrations than something that opened and closed. They may very well have been used for locomotion rather than for grasping. Possibly useful for holding prey stationary while it fed is another possibility.

 

Tom