Jump to content
digit

More Micros From The Peace River And Cookiecutter Creek

Recommended Posts

digit

Here are a few of the micro fossils I've been having fun with recently. I've gathered some micro-matrix from Jeff's magic cookiecutter shark creek as well as some from the Peace River where John and I had good success with large mammal fossils (Proboscideans in particular). I've gone through a couple of plastic Solo cups of the cookiecutter micro-matrix in search of additional specimens of Isistius shark teeth to add to my small but growing collection. In my last batch of micro-matrix from this spot I've found a few nice ones including an unbelievable number of midline (symphyseal) teeth. This batch has already given up two Isistius and they've been nice complete teeth and not the more common fragments. Apparently, I must be some sort of Pied Piper of Isistius or possibly a symphyseal savant as one of these two is a really nice looking tooth with the two overlap notches on the same side marking this tooth as yet another symphyseal--I think this makes 3 or 4 now.

A nice complete symphyseal Isistius and a more common non-symphyseal with a bit of a chip on one corner:

post-7713-0-91742400-1434645009_thumb.jpg post-7713-0-81468300-1434645014_thumb.jpg

Cheers.

-Ken

Share this post


Link to post
Share on other sites
digit

The Peace River micro-matrix has given up a few other interesting micros as well. I've seen photos in ID books and on this forum of crab claws/pincers (chelae) but haven't come across any (till now). In one cupful of micro-matrix I managed to pull out two similar looking fragments of what appear to be chelae. This makes me suspicious that they may be associated but, as always, in the Peace River these two items could be from widely separated eras and individuals. Pretty cool to be able to add some novel items to my little collection of micros.

post-7713-0-81325200-1434645952_thumb.jpg

I've also found what looks much like the upper incisor of a small rodent that I found in Peace River micro-matrix last year. This one is insanely tiny--only about 7 mm in length and roughly 1 mm thick. One end does appear to have that sheared/worn looking end contour (lower right in photo) that you would expect from aradicular hypsodont teeth that are continuously worn down against the lower incisors. This one is probably half the size of the one I found last year and had me wondering if it might be something else like a curved rib bone or something that was fractured in such a way as to appear to be an incisor with a worn occlusal surface but I still believe it to be dental and that I'm just second guessing myself as I'm skeptical and quite novice at these types of fossils (though I seem to be gathering quite the menagerie of tiny rodent dentition).

post-7713-0-69020600-1434645958_thumb.jpg

Cheers.

-Ken

Share this post


Link to post
Share on other sites
digit

Then there is this odd little item. The shiny black outer surface has very slight striation markings (which don't really photograph too well). This thing is so tiny and hard to position for photographs that photos against my big pink fingerprints were the only way to easily position it for different angles of view (working on a better system). That I take to be an occlusal surface seems to be filled with a lighter material that almost appears to be a finely powdered sandlike material (but is quite solid though it does appear to have an odd darker inclusion). I'm going to try to find a way of stabilizing this item in something like clay or that tacky gummy stuff they use to hang posters these days and see if I can dislodge anything from this surface with a fine pin. This surface is approximately 2 x 3 mm and the overall length of this is around 4.5 mm.

If, indeed, this is a tooth then I would have to assume another tiny beastie on the order of a small rodent. Haven't started flipping through my ID books yet to see if I can spot something approximating this. In the meantime I thought I'd post it here to see what feedback I get. Micro picking can sometimes find some real interesting items and I'm having a blast learning about the diversity of critters that would normally slip through our strainers.

Here are three different views (mostly in focus):

post-7713-0-99018700-1434647429_thumb.jpg post-7713-0-11550900-1434647357_thumb.jpg post-7713-0-21530800-1434647362_thumb.jpg

Cheers.

-Ken

Share this post


Link to post
Share on other sites
lissa318

Nice finds Ken!!! I love the cookiecutter teeth. I haven't gone through any of my micro matrix in awhile... You're making me want to get back at it. ;)

Share this post


Link to post
Share on other sites
digit

Set aside some time if you do as it can be highly addictive--just another cupful and then I'll get back to work (my common refrain).

Cheers.

-Ken

Share this post


Link to post
Share on other sites
ynot

That is a nice group of finds. Good luck with the rest of Your matrix.

Tony

Share this post


Link to post
Share on other sites
megaholic

That last item looks like a small dolphin tooth that is worn/broken maybe? Or, is it too small for that? Sometimes re-wetting the hardened matrix in it will soften it up for removal. Try a stiff glue brush, or the pin. There is probably some detail under it. Does not strike me as a fish tooth, so it probably is!

Share this post


Link to post
Share on other sites
old bones

Nice stuff Ken. You are definitely the Pied Piper of Isistius symphyseals! I still haven't found one of those yet. That is a nice rodent incisor...probably one of those pesky marsh rats or cotton rats again. The other tooth might be a fish tooth. It looks a lot like some I've found. It's probably hollow up to a point and filled with matrix. Good luck cleaning it.

Edited by old bones

Share this post


Link to post
Share on other sites
jcbshark

Wow Ken, that's pretty incredible finding all those symphyseals! I've found some crab bits like those at Caspersons : )

Share this post


Link to post
Share on other sites
digit

During this morning's micro sorting I came across what appears to be yet another incisor. If this is what it turns out to be then these are really not all that uncommon (or I've discovered that my latent superpower is locating rodent incisors and cookiecutter symphyseals--not as good as the power of flight or invisibility, but I'll take it ;)). This would be the third upper incisor from three very different rivers/creeks in South Florida. This item looks a bit different from the others though so I'm far from certain in my identification based on such a small (but apparently ever growing) sample size. Rather than a relatively uniform thickness (laterally) this proposed incisor narrows to a much more pointed occlusal tip. This narrowing would be difficult to photograph with my current setup but would be in the dimension perpendicular to the photo below. The tip does have a bit of a chiseled end to it but, being thin at this end, does not show the wear marks where this tooth would have worn against a lower incisor as well as in my other specimens. The "root" end is broken and jagged and shows this end to be hollow for some distance. This specimen does not have apparent striations along it length but the rough surface may just be do to weathering. I've done web image searches for "rodent rib" which is the only other option that I could think of that might resemble this but it seems this item still looks more incisor-like than anything else.

post-7713-0-40545000-1434724908_thumb.jpg

Cheers.

-Ken

Share this post


Link to post
Share on other sites
digit

The other notable find in this morning's sorting was a small shark tooth that I initially took to be a broken and worn tooth. Upon closer inspection I noticed it wasn't a "normal" T-shaped tooth with one half of the wide root broken away but a laterally compressed and slightly hooked tooth. My first hope was that it was an elusive Rhincodon (whale shark) tooth but after comparing it to the few whale shark teeth images available on the web I decided it didn't really match. So Rhincodon teeth still remain on my bucket list which is good, I guess, as what is the fun of having a short bucket list? The fact that it was laterally flattened made me start thinking symphyseal so I started doing images searches for something that matched closer. I found a few images that shared some of the gross morphology of my find but nothing that was a particular dead ringer (at least to my untrained eye). My best guess is still that it is a very narrow symphyseal (this time NOT from Isistius). I'm hoping to be enlightened by any elasmo dentition experts on the forum.

post-7713-0-11649400-1434726155_thumb.jpg

Cheers.

-Ken

Share this post


Link to post
Share on other sites
ynot

Hey Ken,

Some more cool finds!

The last one looks more like a claw than a tooth to Me.

Tony

Share this post


Link to post
Share on other sites
digit

It's got some very definite enamel on the surface so I'm leaning tooth over claw. Looking at the lower hemi symphyseal on the link above I can picture a match more if I envision the missing lower portion. The bottom of this tooth has a broken surface and the tooth is much more of a match for a lower hemi symphyseal if you picture the power portion of the root below the red line missing (photo borrowed from the www.fossilguy.com website link above).

post-7713-0-00347600-1434731167_thumb.jpg

This will be my best guess unless proven otherwise.

Cheers.

-Ken

Share this post


Link to post
Share on other sites
Plantguy

Interesting small finds Ken---especially the first couple of shark teeth! congrats! Regards, Chris

Share this post


Link to post
Share on other sites
old bones

The other notable find in this morning's sorting was a small shark tooth that I initially took to be a broken and worn tooth. Upon closer inspection I noticed it wasn't a "normal" T-shaped tooth with one half of the wide root broken away but a laterally compressed and slightly hooked tooth. My first hope was that it was an elusive Rhincodon (whale shark) tooth but after comparing it to the few whale shark teeth images available on the web I decided it didn't really match. So Rhincodon teeth still remain on my bucket list which is good, I guess, as what is the fun of having a short bucket list? The fact that it was laterally flattened made me start thinking symphyseal so I started doing images searches for something that matched closer. I found a few images that shared some of the gross morphology of my find but nothing that was a particular dead ringer (at least to my untrained eye). My best guess is still that it is a very narrow symphyseal (this time NOT from Isistius). I'm hoping to be enlightened by any elasmo dentition experts on the forum.

attachicon.gifsymphyseal.jpg

Cheers.

-Ken

Ken, I think ShellSeeker is right on this being a Hemi. I have several like it and used to post them for ID thinking they were claws. Then I was set straight about them being possible Hemipristis syphyseals. It makes sense as there are a lot of Hemi teeth in the Peace Matrix. I will try to to find my old (much greener) post. :)

Share this post


Link to post
Share on other sites
digit

Few more interesting items turned up yesterday while sorting. The first one I took to be some sort of worn shark tooth (no particular enamel visible). It's got an interesting S-curve profile on each side unlike shark teeth. It's about 4.5 mm long by around 4 mm wide at the base. I'm wondering if this might be the 'thorn' from a ray dermal denticle? Still sitting in my to-be-identified pile at the moment.


post-7713-0-69009100-1435174281_thumb.jpg

Cheers.

-Ken

Share this post


Link to post
Share on other sites
digit

The coolest tooth of the day has to be what I believe to be another Sigmodon (cotton rat) molar. The occlusal surface is roughly 2.0 x 2.3 mm and it is about 2.5 mm high. A tiny tooth by any measure but distinctive enough to have popped into view quite obviously while sorting through the fine black gravel on my white paper plate. I'm beginning to build quite the collection of rodent molars and incisors while scanning this micro-matrix. Always fun to find--always a pain to try to photograph.


post-7713-0-39983000-1435174676_thumb.jpg post-7713-0-50273600-1435174677_thumb.jpg

Cheers.

-Ken

Share this post


Link to post
Share on other sites
snolly50

Here are a few of the micro fossils I've been having fun with recently. I've gathered some micro-matrix from Jeff's magic cookiecutter shark creek as well as some from the Peace River where John and I had good success with large mammal fossils (Proboscideans in particular). I've gone through a couple of plastic Solo cups of the cookiecutter micro-matrix in search of additional specimens of Isistius shark teeth to add to my small but growing collection. In my last batch of micro-matrix from this spot I've found a few nice ones including an unbelievable number of midline (symphyseal) teeth. This batch has already given up two Isistius and they've been nice complete teeth and not the more common fragments. Apparently, I must be some sort of Pied Piper of Isistius or possibly a symphyseal savant as one of these two is a really nice looking tooth with the two overlap notches on the same side marking this tooth as yet another symphyseal--I think this makes 3 or 4 now.

A nice complete symphyseal Isistius and a more common non-symphyseal with a bit of a chip on one corner:

attachicon.gifIsistius1.jpg attachicon.gifIsistius2.jpg

Cheers.

-Ken

Hey Ken, I'm not getting it. Please repost the photo with the notches that you reference marked. Thanks!

Share this post


Link to post
Share on other sites
digit

Hey Ken, I'm not getting it. Please repost the photo with the notches that you reference marked. Thanks!

Sure, always happy to elucidate. On normal (non-symphyseal) teeth each tooth overlaps and is overlapped by the teeth on either side. Much like how an asphalt shingle overlays a portion of the shingle in the row below it and is itself partially overlain by the row of shingles above it. I've crudely marked in red the notch area in the non-symphyseal tooth. Note that there is one notch (area where the tooth is thinner) on either side of the tooth (both sides are shown in the photo:

post-7713-0-48990800-1435180040_thumb.jpg

Now in the symphyseal tooth both notches are on a single side of the tooth (also crudely highlighted in red). This would be like the ridge cap shingle that lies above the shingles on both sides. The roof tile/shingle analogy is just about the perfect comparison as far as I can come up with.

post-7713-0-80998500-1435180037_thumb.jpg

If you do an image search on the web for "cookiecutter shark teeth" you will see a number of cool examples of why I've always been fascinated with this shark since I was a wee tot. My go-to picture I usually show someone when trying to explain the wonders of this shark's dentition is usually on this page:

http://www.teara.govt.nz/en/photograph/5321/jaws-of-a-cookie-cutter-shark

post-7713-0-89008800-1435180881_thumb.jpg

I've cropped out a bit of the image of the lower jaw (where these A-frame house shaped teeth are located). I zoomed into this lower resolution image and located the symphyseal row in the midline of the lower jaw. I've again crudely tried to indicate how the teeth overlap. Once you've looked at my marked up version check it against the unmarked version on the New Zealand website for an unobscured view. There seem to be about 30 teeth per row in this particular jaw so the odds of a symphyseal are probably about 3% on any tooth you might encounter. I know I'm running well above that average at the moment.

Hope this is informative and helps you to be able to identify Isistius symphyseals.

Cheers.

-Ken

Edited by digit

Share this post


Link to post
Share on other sites
ynot

Hey Ken,

Those are some really cool teeth.

Also that is a real good explanation of the cookiecutter symphyseal tooth.

Thanks,

Tony

Share this post


Link to post
Share on other sites
digit

Thanks. When I found my first complete Isistius tooth from micro-matrix collected at Jeff's magic Cookiecutter Creek location I was happy to have been able to find a tooth from one of my favorite species of sharks. I mean how can you lot love a tiny shark with suction lips and half a hole saw for a lower jaw and to top that a belly covered with light-emitting photophores? I was not attuned to the fact that the tooth I found was a symphyseal and after being informed about this was happy to learn about the slightly overlapping rows that must add structural integrity to the active series of teeth in the lower jaw. If you've ever seen the wounds this little shark can inflict on larger fishes/whales you'd agree that the plugs of flesh they remove make me think this shark should have been named the "ice cream scoop shark" (though "cookiecutter" rolls of the tongue better). Many grazing snails have a radula composed of teeth made with iron oxides (primarily hematite). Lets hope there is no convergent evolution in the cookiecutter sharks or we may one day find fossils that look like this:

post-7713-0-21333700-1435237026_thumb.jpg

Cheers.

-Ken

Share this post


Link to post
Share on other sites
snolly50

Ken, very clear, thanks.

Share this post


Link to post
Share on other sites
digit

You're welcome. As I've heard it the only two things that can be shared without being diminished are love and knowledge. This forum has taught me so much that I'm always happy to return the favor when I can.

Cheers.

-Ken

Share this post


Link to post
Share on other sites
snolly50

Ken

Your cogent elucidation

evoked a bout of cogitation.

You saved me from ignoration,

Hence, this felicitation.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.

×