Carboniferous Shark Tooth? Oglesby, IL

[gieserguy]

Hey guys! It’s been a while since I’ve been active, it’s good to be back

 

My roommate and I took a trip out to Oglesby, IL today for his first fossil hunt! We found some nice brachiopods, but the absolute winner for me were two associated shark teeth (I think). It might be a cladodont, but sharks are really out of my spectrum, so if anyone could help I’d be quite appreciative! 
 

Oglesby, IL

LaSalle Limestone Member

Bond Formation

Carboniferous, Pennsylvanian

 

Tooth 1

 

Tooth 1 wet

 

 

Tooth 2

 

Tooth 2 wet 

[Fossildude19]

Welcome back! Good to see you here again. 

 

What a great set of finds!

Maybe @jdp  @Archie  @connorp  @JimB88 can chime in on these! 

[Tidgy's Dad]

Nice finds and good to see you back.

[Misha]

Lovely little teeth! 

 

[gieserguy]

@Fossildude19 @Tidgy's Dad @Misha Thank you all! I’ve missed this great community. 

And thanks for the compliments on the find as well! I’m super excited about it, I never thought I’d find a shark tooth around here. Even if they’re nothing super special, these two tiny teeth are my yearmaker. I spotted the first one, but roommate was the one who found the second one! Great find for his first ever fossil hunt 

[jdp]

Heslerodus, maybe?

[fossilsonwheels]

I think possibly Heslerodus as well

[deutscheben]

Very nice teeth! I have a rather partial one from that site that also looks like Heslerodus, that seems to be a good ID to me.

[Nimravis]

Nice finds, I almost headed out there today too, but opted to straighten out some fossils in my collection.

[connorp]

@gieserguy Glad to see you are back! Shark teeth are always a treat at that site, especially rarer ones such as these.

 

@jdp @fossilsonwheels @deutscheben Could you explain why you think Heslerodus? The median cusps in both teeth are relatively larger than the lateral cusps, whereas I believe they should be of similar size in Heslerodus. I would be more inclined to think that these are small Glikmanius teeth. I believe others members have found Glikmanius teeth from this site, whereas I am unfamiliar of any reports of Heslerodus from Illinois.

[fossilsonwheels]

17 minutes ago, connorp said:

@gieserguy Glad to see you are back! Shark teeth are always a treat at that site, especially rarer ones such as these.

 

@jdp @fossilsonwheels @deutscheben Could you explain why you think Heslerodus? The median cusps in both teeth are relatively larger than the lateral cusps, whereas I believe they should be of similar size in Heslerodus. I would be more inclined to think that these are small Glikmanius teeth. I believe others members have found Glikmanius teeth from this site, whereas I am unfamiliar of any reports of Heslerodus from Illinois.

I based my guess, and it is just a best guess, on a photo from a paper on Heslerodus plus the small size. I found reference to Heslerodus from a 1985 paper on the Excello Shale Member of the Carbondale Formation in Grundy County Ill while searching Fossilworks.

 

I thought the first tooth in particular might possibly be Heslerodus but I am no expert by any means.

[gieserguy]

Something I may have failed to fully mention- I called the teeth “associated” as I’m presuming both teeth are from the same animal, they were both on the same plane of the same stone, just about a foot apart from each other. 

[connorp]

18 minutes ago, fossilsonwheels said:

I based my guess, and it is just a best guess, on a photo from a paper on Heslerodus plus the small size. I found reference to Heslerodus from a 1985 paper on the Excello Shale Member of the Carbondale Formation in Grundy County Ill while searching Fossilworks.

I have access to a dissertation of the same name by the same author, but from 1979. So it may be slightly different than the one you're looking. The dissertation describes a species later referred to Heslerodus, but it is from the Mecca Quarry Shale in Indiana. The Excello Shale in Illinois is mentioned but not in reference to Heslerodus. Of course, this all does not preclude the presence of Heslerodus in Illinois. I also might be totally wrong with my guess, I am no expert either.

[doushantuo]

link to this one following shortly(17 MB)

 

 

here

Heslerodidae(chondrichthyes,Elasmobranchii),a new family of Paleozoic Phalacanthous sharks

John G.Maisey/Kirtlandia,v.57 2010

 

 

 

 

 

 

 

 

 

 

[fossilsonwheels]

9 minutes ago, connorp said:

I have access to a dissertation of the same name by the same author, but from 1979. So it may be slightly different than the one you're looking. The dissertation describes a species later referred to Heslerodus, but it is from the Mecca Quarry Shale in Indiana. The Excello Shale in Illinois is mentioned but not in reference to Heslerodus. Of course, this all does not preclude the presence of Heslerodus in Illinois. I also might be totally wrong with my guess, I am no expert either.

The one I saw was published in 85 I think. I’ll look it up again. 

[doushantuo]

some of you may like to know of the existence of this:

https://www.cambridge.org/core/journals/journal-of-paleontology/article/problem-of-vast-numbers-of-cladodont-shark-denticles-in-the-pennsylvanian-excello-shale-of-pike-county-indiana/04C32CDD771B17640B1B1FA74182E962

Furthermore I own/have at home:

The «cladodont level» sharks of the Pennsylvanian black shales of central North America
Williams, Michael E.
Palaeontographica Abteilung A Band A190 Lieferung 3-6 (1985), p. 83 - 158

published: Jan 1, 1985

[deutscheben]

@connorp I can see what you are saying about Glikmanius (which I have indeed found from this site) for the first one especially, but the lateral cusps seem kind of proportionally large on the second one. Then again, they are both so tiny and incomplete, it’s hard to tell. And since they were found so close together, it seems likely they would come from the same species, not 2 different ones. So now you have me thinking parsimony would indicate Glikmanius 

[gieserguy]

Oh I just remembered about my little clip-on phone microscope! So here’s some nice closeups of the teeth 

 

Tooth 1

 

Tooth 2

[jdp]

The fact Heslerodus has not previously been reported from those rocks shouldn't be a surprise since it's a relatively recently erected genus. Generally, these marine shark faunas are pretty widely distributed, so presence/absence in a specific formation in comparison with similar-aged formations in the same region is probably due to sampling and recency of faunal revision rather than a real biological feature.

 

That first tooth especially seems to have the gracile arched root and elongate lateral cusps that characterize Heslerodus, but I will note that teeth this small can be difficult to ID with confidence.

[deutscheben]

Now that I am on campus I was able to look at a few additional resources. Looking at images from the paper Ctenacanthiform sharks from the Permian Kaibab Formation, northern Arizona Hodnett et al 2012 (https://www.researchgate.net/publication/254237970_Ctenacanthiform_sharks_from_the_Permian_Kaibab_Formation_northern_Arizona), which depicts both Glikmanius and Heslerodus, I would say these teeth bear more of a resemblance to the latter. The divergent and large lateral cusps look like Heslerodus- I can't find any images of Glikmanius where the lateral cusps approach the size of the median cusp like they do on those ones. 

Looking at the paper referenced on Fossilworks (M. E. Williams. 1985. The "Cladodont level" sharks of the Pennsylvanian black shales of central North America)- it does describe Heslerodus remains from the Excello Shale in Illinois, from Pit 12 in the Mazon Creek area, so there is some record of the genus in Illinois. 

I think a case could be made either way, but now I find myself swinging back towards Heslerodus. 

[Archie]

Awesome finds! My first thought was Glikmanius as well but I'm really not very knowledgeable about the species on that side of the pond and it definitely makes things trickier when teeth are smaller.

[connorp]

1 hour ago, deutscheben said:

Now that I am on campus I was able to look at a few additional resources. Looking at images from the paper Ctenacanthiform sharks from the Permian Kaibab Formation, northern Arizona Hodnett et al 2012 (https://www.researchgate.net/publication/254237970_Ctenacanthiform_sharks_from_the_Permian_Kaibab_Formation_northern_Arizona), which depicts both Glikmanius and Heslerodus, I would say these teeth bear more of a resemblance to the latter. The divergent and large lateral cusps look like Heslerodus- I can't find any images of Glikmanius where the lateral cusps approach the size of the median cusp like they do on those ones. 

Looking at the paper referenced on Fossilworks (M. E. Williams. 1985. The "Cladodont level" sharks of the Pennsylvanian black shales of central North America)- it does describe Heslerodus remains from the Excello Shale in Illinois, from Pit 12 in the Mazon Creek area, so there is some record of the genus in Illinois. 

I think a case could be made either way, but now I find myself swinging back towards Heslerodus. 

I must have missed that description in the 1985 paper. Thanks for pointing it out.

 

With the new pictures, I think Heslerodus is a safe bet. I will be on the lookout for these small teeth at Oglesby from now on. Thanks for starting this fun discussion @gieserguy

[gieserguy]

This thread has been so much fun to watch go back and forth! Thank you to all who commented and helped with the ID of these itty bitty teeny weeny teeth. I learned quite a bit from you all  

[fossilsonwheels]

3 hours ago, gieserguy said:

This thread has been so much fun to watch go back and forth! Thank you to all who commented and helped with the ID of these itty bitty teeny weeny teeth. I learned quite a bit from you all  

A really fun and informative thread for sure. Those teeth are really awesome. Great find.