Octopus?

[doug10k]

Can somebody help identify this and give me an idea how old it is?  I found it on a dirt road about a mile from the Potomac River in Western Maryland, and about 1000 feet up on a ridge.  I can see 8 arms (one is hard to see, along the edge), so I am thinking this is the arms of an octopus, or something related to it.  But the arms are rather short, and they seem to radiate out like a sea anenome, so maybe not.  This is my first ever fossil find.

[Miocene_Mason]

This is either a brittle star or a crinoid calyx, were you by any chance in the vicinity of Hancock or maybe McCoys ferry?

[Miocene_Mason]

Welcome to the forum from Carroll County by the way! I've hunted out west way. The reason a location would be good is because that area has a ton of different aged rock formations, each with different fauna and flora of fossils. Nice find which ever one (or maybe Something else I haven't considered) it is!

[doug10k]

Yes, near Hancock.

[Miocene_Mason]

2 minutes ago, doug10k said:

Yes, near Hancock.

Than I'd say crinoid calyx and arms. This area has fossils from a turbulent deep sea that large colonies of these grew in. By the way, this fossil is probably from the Devonian (givetian, 350 million years old) Mahantango Formation. Just in case maybe @EMP could take a look (it notifies him when I tag him).

[caldigger]

Sooo, you're thinking it's not something along these lines?  Variety of sea star.

 

[doug10k]

Fascinating. I’ll have to research geological history to see where the ocean was back then and how that land ended up so high (plate tectonics I assume.). Neat stuff like this gets me learning about the region more!

 

I did notice that pictures I just searched for match crinoid calyx more closely, so you are probably right.

 

[Miocene_Mason]

3 minutes ago, caldigger said:

Sooo, you're thinking it's not something along these lines?  Variety of sea star.

 

It's just that I've never heard of any ever being found in the mahantango formation (a formation in which lots of fossil hunting occurs) but I could always be wrong. Hey @doug10k, which formation does it say you are in here: http://www.mgs.md.gov/esic/geo/was.html

the map is old and sometimes inaccurate but it should work roughly.

[caldigger]

Alrighty, you know your areas better than I. Nice showy sample though.

[Miocene_Mason]

1 minute ago, caldigger said:

Alrighty, you know your areas better than I. Nice showy sample though.

Never assume that! I'm still newish to fossil hunting so I still haven't seen all Maryland can through at me. That's why I called in @EMP for he knows much more about that area than me.

[caldigger]

Well, since I have never been to Maryland, you have me beat by a mile.

[doug10k]

It was about 30 min west in Allegeny County, on the east face of the big ridge parallel to Oldtown Orleans Rd, looking down on the potomac.  I think it was Mertens Ave.

[Miocene_Mason]

6 minutes ago, doug10k said:

It was about 30 min west in Allegeny County, on the east face of the big ridge parallel to Oldtown Orleans Rd, looking down on the potomac.  I think it was Mertens Ave.

In this case, it is probably the Harrell or (more likely due to elevation) Brallier formation. These are slightly younger than the Mahantango. Now I'm back to square one of not being sure, I found This fossil online, same formation. Maybe emp or someone with an affinity for echnoderms will know more. If you find yourself back there, check for more, a more complete one could solve the mystery. 

[ynot]

Welcome to TFF!

Apparently "starfish" are old enough to be in the formation.

I do not see the type of segmentation I would expect from a crinoid, nor do I see the "feathering" I would expect to see in crinoid arms. Also I see no evidence of a calyx.

I agree with @caldigger that it is a multi legged starfish.  

 

Very nice find, especially for a first time!!

[doug10k]

Interesting...  I did look around for more and the only other one I saw was similar to that one!  But it didn’t look like an obvious fossil to me, and the rock was too hard to dig out of the road anyway, so I left it there.  My mother always told me not to play in the road!

 

Thank you all for your feedback!

[EMP]

That area is home to both the Hamilton Group, and the Brallier and Harrell Shale, so it sounds like finding which formation is a little tricky. Usually the Harrell doesn't form ridges as it tends to be a softer shale that erodes into small valleys. Also, it doesn't have the Harrell look to it (the Harrell is often a very dark gray and black fissile shale) so I think it's safe to rule it out. The Brallier is usually a dark fissile shale, too, but it does have some more massive siltstone and shale interbeds and can form local highpoints, especially along natural objects like creeks. Going on, brittle star trace fossils are moderately common from the Brallier. However, although lithologically it could be a piece of the Brallier, the fossil preservation makes it unlikely, as the yellowish coating is more indicative of the Hamilton Group rocks in this region and, to a minor degree, the Foreknobs (however it sounds like this wasn't found in Foreknobs territory, as the Foreknobs isn't a big ridge forming unit). 

 

However, at closer look I don't think it's most likely any sort of sea star or brittle star, as this fossil would have more than eight "arms". Also, although some trace fossils of them are known from the Brallier, the problem becomes that this isn't a trace fossil. 

 

Edit: I rescind my initial ID. I think it's a fair contender for a multi armed sea star:

 

 

[KimTexan]

Can we get a close up on some of the arms? #3 from the top down preferably and also the base of the piece where they would all connect.

It almost looks like there are little curled up things on the arms, kind of like a fern fiddle head. I’m not saying it’s a plant. 

Also, are there any round disk shapes with or around the piece? Crinoid stem pieces are really common and seen more often than these parts. You can see some of the shapes in the pic from the web below.

[Fossildude19]

I am in the Starfish camp on this one. 

I wonder if @Carl knows anyone familiar with Devonian Starfish? 

 

 

EDIT: ... So, there is a multi legged starfish from the Devonian of Germany, but only from one locality there, ... Budenbach. Helianthaster

There is an odd, starfish looking Devonian crinoid, however.  Acanthocrinus rex.

 

Now I'm confused. 

[westcoast]

Wow! What a start to fossil collecting!  I agree, my first impression is starfish. The way the relatively short arms radiate from a central area is less likely in a crinoid. 

[Rockwood]

+1 in starfish camp. The preservation is a much better fit all around.

[TqB]

Another vote for starfish. Compare with Arkonaster from the Devonian of Arkona. Amazing find! - I can think of one or two professionals who would probably be interested.

There are one or two good images online, also:

pdf: Kesling 1982 Arkonaster...

 

reconstruction from that paper:

 

[Manticocerasman]

Wow, for a first ever fossil find this is a great start

+1 for starfish

[EMP]

5 hours ago, Fossildude19 said:

I am in the Starfish camp on this one. 

I wonder if @Carl knows anyone familiar with Devonian Starfish? 

 

 

EDIT: ... So, there is a multi legged starfish from the Devonian of Germany, but only from one locality there, ... Budenbach. Helianthaster

There is an odd, starfish looking Devonian crinoid, however.  Acanthocrinus rex.

 

Now I'm confused. 

 

Only problem is that no asteroids are reported from any rocks other than the Brallier in Maryland, and even then the only fossils of them are traces made from brittle stars, which this is too wide and too many arms to be one. 

 

 

[doushantuo]

"EUCLADIA"

Edit:to clear up confusion: I think Schuchert figured an ophiocistoid.

If the specimen disussed here were to be one,that would be a humongous find

edit:Schuchert,1915 Us Nat. Mus "American Paleozoic Asteroidea"

Sollas ' s(1899) Euthemon ?

[westcoast]

16 minutes ago, doushantuo said:

"EUCLADIA"

Ophiocistoid ,methinks?

edit:Schuchert,1915 Us Nat. Mus "American Paleozoic Asteroidea"

Nice one. I haven't come across this creature before.