Trilobite Legs?

[noahc0d]

Maybe a dumb question, do the legs of the trilobite preserve often along with the rest of the animal? When I look it up I see ones with legs that are flat, but I'm thinking 3d. If not, why?

[Paleostoric]

Not a dumb question! We are all here to learn more. 

Trilobite legs are not often preserved compared to the hard exoskeleton we generally see with trilobite fossils because the legs are considered soft tissue. Soft tissue rarely ever fossilizes as they often decay before being able to undergo the fossilization process. Some of the most exquisite preservation of trilobite soft tissue comes from the Beecher's Trilobite Bed with pyritized Triarthrus eatoni trilobites, so you may want to look that up if you are interested in learning more about them. The legs may appear flat because they not only went under the fossilization process, which involves often high amounts of pressure over millions of years, but also because legs of the smaller trilobites were thin. However, my knowledge about trilobites is quite limited, and there are plenty of trilobite experts here on the forum that can help you out more!

[Fossildude19]

LINK to IMAGES of Trilobites with Legs.

[Kane]

If you cannot acquire a copy of the Treatise O: Arthropoda, Sam Gon III has an informative page discussing appendages as part of the section on ventral morphology here. 

[noahc0d]

15 hours ago, Paleostoric said:

the legs are considered soft tissue

Wow, that's really interesting, I always thought of them like lobster/crab legs (just on a different animal lol). Very informative post, I always like learning fun things like that. I looked up Triarthrus eatoni, and looking at some of the specimens is mind blowing seeing the individual sections of the antenae like that is fascinating.

13 hours ago, Fossildude19 said:

LINK to IMAGES of Trilobites with Legs.

Thanks!

12 hours ago, Kane said:

Treatise O: Arthropoda

That looks very interesting, though very expensive lol. From what I can see it's an encyclopedia kind of thing, is that right? I've saved that page, very cool thank you! By the way I came across your blog a while ago, before I joined the forum and thought it was cool to see in depth local stuff like that, so it's cool to see you here!

 

Another question; Are trilobites preserved while rolled up more likely to have their legs preserved as well? My thinking is that it wouldn't be weathered away (as easily at least), though I have doubts because they might just decay.

[Paleostoric]

3 hours ago, noahc0d said:

Are trilobites preserved while rolled up more likely to have their legs preserved as well?

I'm not entirely sure but usually the conditions have to be exactly right for soft tissue preservation to occur. For example, for the pyritized trilobites they were buried very quickly under anoxic conditions when they died, which prevented normal decomposition from occurring and allowed for the replacement of the soft tissue by pyrite. Rolling in trilobites is interesting though since it is more of an adaptation seen with trilobites after the Cambrian as a defense mechanism against predators. It is a fairly common occurrence to see in trilobites. Some of the trilobites that come to mind when I think of rolling are Flexicalymene and Eldredgeops.

[Kane]

9 hours ago, noahc0d said:

That looks very interesting, though very expensive lol. From what I can see it's an encyclopedia kind of thing, is that right? I've saved that page, very cool thank you! By the way I came across your blog a while ago, before I joined the forum and thought it was cool to see in depth local stuff like that, so it's cool to see you here!

 

Another question; Are trilobites preserved while rolled up more likely to have their legs preserved as well? My thinking is that it wouldn't be weathered away (as easily at least), though I have doubts because they might just decay.

The Treatise volumes are somewhat "encyclopedic," as they function as a resource to present the morphology and characteristics of the phyla under treatment, followed by (in some cases) geographic distribution, and representative taxa within those phyla. 

 

Thanks for the kind words about the blog (which sorely needs an update). The Ontario circle of collectors is a small one, so eventually we all bump into each other at some point.  

 

I don't think the mechanism of enrollment would increase the odds of preserved appendages (and if so, the legs would not be visible). Mineralization/replacement is fairly thorough. That being said, without any Lagerstatte-Konservat areas in Ontario that are trilobite-bearing, there would be almost no chance of finding any leggy wonders here. 

[noahc0d]

21 hours ago, Paleostoric said:

the conditions have to be exactly right for soft tissue preservation to occur.

Oh ok, so it's not so much the legs being physically destroyed, as just decaying. I wonder if there are any traces of where the legs would be (leftover carbon? idrk)

 

15 hours ago, Kane said:

The Treatise volumes are somewhat "encyclopedic," as they function as a resource to present the morphology and characteristics of the phyla under treatment, followed by (in some cases) geographic distribution, and representative taxa within those phyla.

That sounds interesting, I wonder if any local libraries might have it. Do you have to be a student to access a university library?

15 hours ago, Kane said:

The Ontario circle of collectors is a small one, so eventually we all bump into each other at some point.  

I've only ever met one other collector in person, and it was a cool experience. It was one of my trips to Arkona and we talked about trilobites and I showed him one I found that day. I wonder what the actual number is like. Anyways, it's especially cool to see someone local to me as a moderator on a huge forum like this.

 

15 hours ago, Kane said:

without any Lagerstatte-Konservat areas in Ontario that are trilobite-bearing

Are there any such areas that aren't trilobite bearing in Ontario? As far as I know Arkona is the closest thing to one, but then again I don't know a whole lot lol.

[Kane]

I have access as a prof at Western, and I'm relatively certain our students have access to whatever the university library has or subscribes to in terms of journals. But in terms of the Treatise, I found a cheap used copy online. 

 

In terms of collector numbers, the "serious" collectors are very few.  

 

And in terms of our Lagerstatte, none are trilobite-bearing.  Ontario has some great riches, but also some major gaps. For instance, southern Ontario's Silurian is largely pointless for trilobites. Our Devonian outside Arkona is tough and sparse for trilobites (with fewer locations). Our Ordovician is the best hope, but no quarries anymore so it becomes a game of water-worn lake rocks or getting in on the few leases out there, but that is generally closed out.

[noahc0d]

@Kane Oh that's awesome, I have a couple friends going there next year.

 

So there are Lagerstatte here? I was under the impression that there were like only a handful in the world.

 

How common is it for quarries to contain fossils?

Also, I know there's Ordovician fossils up on Manitoulan (I was lucky to have friends bring me back some coral ). Is that area (around lake superior) common for deposits?

I'm asking because I've always dreamed of owning land in northern(ish) Ontario, and looking I've seen properties that include aggregates. I think it would be amazing to have fossiliferous deposits in your own backyard (open to the public of course).

 

I wonder if it would be feasible to crowdfund buying an abandoned quarry for fossil hunting

[Kane]

There are Lagerstatte, but they are small and in Silurian quarries, with exclusive access to the ROM. You are not missing much. I was granted access and it is crappy plant material mostly, and it takes about 400 hours to find a scorpion. Tetrault’s thesis and the ROM was likely powered by the finds made by the quarry workers who did the work everyday.

 

Manitoulin will be tough. The island is mostly Silurian.  The Ordovician generally are exhausted road cuts, very weathered. 

 

Up north, you’re maybe looking at James Bay (like Moosonee, where you can only get their by rail). Elsewhere is mostly Canadian shield. Getting around up that area usually requires the use of boats and helicopters. And don't forget the deet!  

 

As for buying an old quarry, that would be expensive. You’d still be on the hook for buying and complying with the province’s aggregate license if any extraction will be done. The legality of that is thick, and hopefully you have a lot of cash to do that! If it is Ordovician, forget about it: some of those quarries still run at a million dollars a day. The abandoned ones that would be generally near the big cities (even land that would have to be remediated prior to development) likely is expensive.

 

I think the problem with abandoned quarries is that they likely have been picked over, and are overgrown and very weathered.  

 

But, living up north is a good dream! Our north is probably the last patches of Ontario that are still halfway affordable these days!

 

In terms of buying an abandoned quarry, it is probably better to lease (if you can). Imagine the initial cost of buying up that old quarry, tapping it out, and being left with land that is not suitable for development. The cost of land remediation is astronomical. 

[noahc0d]

Oh ok, ROM is Royal Ontario Museum right?

 

Oh ok, I guess they're Silurian corals.

 

It's a shame everything is so expensive. I imagine liability is the main reason quarries aren't open to collectors. 

 

Speaking of quarries and collectors, do you know if the one in arkona has had clubs there recently? I've tried looking on their websites but I find them hard to navigate.

[Kane]

36 minutes ago, noahc0d said:

 

 

Speaking of quarries and collectors, do you know if the one in arkona has had clubs there recently? I've tried looking on their websites but I find them hard to navigate.

That would probably be the London club, but you can pretty much just go whenever. People have been going there to fish, walk their dogs, and dig for fossils for over a hundred years. 

[noahc0d]

@Kane Oh ok good to know, I'll be heading there soon now that we're opening up

 

Edit: Does that go for both of them?

Edited May 23, 2021 by noahc0d

[Kane]

12 minutes ago, noahc0d said:

@Kane Oh ok good to know, I'll be heading there soon now that we're opening up

 

Edit: Does that go for both of them?

Both pits? Yup. And along the river, too. Just don't travel across the south bank without the property owner's permission, and there will now be a no trespassing sign if you travel too far up the north bank, so don't dig there.

[noahc0d]

@Kane

Good to know, thanks!