Cookie cutter creek micro matrix search

[Notidanodon]

Hi guys  I won some matrix from a forum auction, thanks @Monica for putting it up

so I’ve searched about half of it and this is what I’ve found so far

i need to do research on the species found in the creek but I have grouped them vaguely into families 

 

1. Shells, I won’t bother identifying these

 

2. Fish jaws

 

3. the best quality ray bars, myliobatis sp. I think

 

4. Various carcharinus species

 

5. Various negaprion species

 

 

6. Phyllodus species

 

7. daysatis sp.

 

8. Mustelus sp.

 

9. daysatis sp.

 

10. Various button fish teeth

 

11. Lagodon sp.

 

12. Pointy fish teeth

 

13. ray spines

 

14. The real prize, Isitius triangularis 

 

15. the random broken bits and bobs

 

[Notidanodon]

Almost forgot

16. the only sand tiger shark tooth, Carcharias vorax probably

 

17. Sphyrna sp, likely various species

 

 

And that’s all for today ladies and gentlemen  I’ll see you tomorrow 

[Al Dente]

19 minutes ago, will stevenson said:

2. Fish jaws

Nice finds. I think at least 2 of these are crab claw pieces.

 

 

[Al Dente]

22 minutes ago, will stevenson said:

8. Mustelus sp.

 

These look like Rhynchobatus.

[fossilsonwheels]

Hi Will

 

Nice finds. There is a paper on the Tamiami Formation. I will see if I can find a link. I agree with @Al Dente on the Rhynchobatus.  The Sand Tiger is going to be C. taurus most likely as it is the only species in the paper if I remember correctly. I think the Sphyrna teeth are Rhizoprionodon. I do not recall seeing Hammerhead teeth in the paper. I could be wrong. Perhaps @digit can help and I will try to find that paper. 

 

Kurt

[digit]

16 minutes ago, will stevenson said:

1. Shells, I won’t bother identifying these

The phosphatic shark tooth layer seems to be the bluish clay layer that lies directly under a layer densely packed with shell hash. Cookiecutter Creek micro-matrix is collected from lag deposits in the creek bed and so is a mix of phosphatic gravel and shelly material. There tend to be lots of broken shell bits but often some nice complete shells--gastropods and bivalves.

 

19 minutes ago, will stevenson said:

2. Fish jaws

Check these carefully. Some may be fish jaws but crab claws with the knobby bits worn off look like jaws with empty alveolae. I've been fooled many times by these. I see Al Dente has commented as well.

 

 

21 minutes ago, will stevenson said:

3. the best quality ray bars, myliobatis sp. I think

Yup. Fairly common in this matrix.

 

23 minutes ago, will stevenson said:

6. Phyllodus species

Definitely pharyngeal teeth but I'm not sure if they can be attributed to Phyllodus.

 

25 minutes ago, will stevenson said:

8. Mustelus sp.

As Al Dente commented these are indeed Rhynchobatus (wedgefish) teeth. There are Mustelus teeth in this micro-matrix but they are much less common. They look quite similar but the roots are different--shorter and stockier than they Rhynchobatus) and the enamel is wrinkled around the base.

 

26 minutes ago, will stevenson said:

10. Various button fish teeth

Indeed. A mixture of pharyngeal "button" teeth. The larger ones may be attributable to drums and the smaller ones may be from wrasses.

 

28 minutes ago, will stevenson said:

12. Pointy fish teeth

Haven't confirmed postitive IDs on all the point ones but many may be from jacks (Carangidae).

 

28 minutes ago, will stevenson said:

14. The real prize, Isitius triangularis 

 

I'm pedantic on this one--Isistius triangulus

 

30 minutes ago, will stevenson said:

15. the random broken bits and bobs

Always more of these than the complete ones.

 

25 minutes ago, will stevenson said:

16. the only sand tiger shark tooth, carcharias vorax probably

Pretty sure this is just the extant species Carcharias taurus.

 

25 minutes ago, will stevenson said:

17. sphyrna sp, likely various species

There are some Sphyrna teeth in the matrix but they are vastly less common than the Atlantic Sharpnose Shark (Rhizoprionodon terranovae) which are the most common shark tooth when you get to a certain size of matrix. They are an extant shark that grows to around a meter in length--hence, the large number of tiny teeth.

 

https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/rhizoprionodon-terraenovae/

 

 

Cheers.

 

-Ken

 

[digit]

Just now, fossilsonwheels said:

Perhaps @digit can help and I will try to find that paper. 

I believe I've already sent Will the paper. If not, he'll let me know and I'll pass it along.

 

Cheers.

 

-Ken

[Notidanodon]

29 minutes ago, Al Dente said:

Nice finds. I think at least 2 of these are crab claw pieces.

 

 

Thanks, the white areas are all sockets, so I don’t think they can be crabs   As they are concave

[Notidanodon]

28 minutes ago, Al Dente said:

 

These look like Rhynchobatus.

Looking back on it, I think you are right, when I finish looking through all of it , I will try to put better ids on things  thanks for your help

[Notidanodon]

16 minutes ago, digit said:

I believe I've already sent Will the paper. If not, he'll let me know and I'll pass it along.

 

Cheers.

 

-Ken

Hi Ken, yes I forgot to tag you in the post, I’d like to let everyone know Ken has been very helpful in providing info on the subject and I would like to say a big thanks to you  I will re read it tonight to try and get a better idea on identification 

[Al Dente]

21 minutes ago, will stevenson said:

Thanks, the white areas are all sockets, so I don’t think they can be crabs   As they are concave

The knobs on crab claws are heavily mineralized, usually calcium carbonate which will dissolve away in acidic water over time. When the knobs dissolve away they will leave depressions in the claw.

[Notidanodon]

20 minutes ago, digit said:

The phosphatic shark tooth layer seems to be the bluish clay layer that lies directly under a layer densely packed with shell hash. Cookiecutter Creek micro-matrix is collected from lag deposits in the creek bed and so is a mix of phosphatic gravel and shelly material. There tend to be lots of broken shell bits but often some nice complete shells--gastropods and bivalves.

 

Check these carefully. Some may be fish jaws but crab claws with the knobby bits worn off look like jaws with empty alveolae. I've been fooled many times by these. I see Al Dente has commented as well.

 

 

Yup. Fairly common in this matrix.

 

Definitely pharyngeal teeth but I'm not sure if they can be attributed to Phyllodus.

 

As Al Dente commented these are indeed Rhynchobatus (wedgefish) teeth. There are Mustelus teeth in this micro-matrix but they are much less common. They look quite similar but the roots are different--shorter and stockier than they Rhynchobatus) and the enamel is wrinkled around the base.

 

Indeed. A mixture of pharyngeal "button" teeth. The larger ones may be attributable to drums and the smaller ones may be from wrasses.

 

Haven't confirmed postitive IDs on all the point ones but many may be from jacks (Carangidae).

 

I'm pedantic on this one--Isistius triangulus

 

Always more of these than the complete ones.

 

Pretty sure this is just the extant species Carcharias taurus.

 

There are some Sphyrna teeth in the matrix but they are vastly less common than the Atlantic Sharpnose Shark (Rhizoprionodon terranovae) which are the most common shark tooth when you get to a certain size of matrix. They are an extant shark that grows to around a meter in length--hence, the large number of tiny teeth.

 

https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/rhizoprionodon-terraenovae/

 

 

Cheers.

 

-Ken

 

Thanks so much Ken, when I post more of my finds, I will take more time to give proper id’s  thanks once again for your help, 

[JohnJ]

Some of your #13 "ray spines" look more like catfish pectoral spines.

[Notidanodon]

14 minutes ago, Al Dente said:

The knobs on crab claws are heavily mineralized, usually calcium carbonate which will dissolve away in acidic water over time. When the knobs dissolve away they will leave depressions in the claw.

That’s interesting  thanks, here’s a photo of the other sides, they are also concave

[Notidanodon]

5 minutes ago, JohnJ said:

Some of your #13 "ray spines" look more like catfish pectoral spines.

Thanks  How should I tell the difference

[Trevor]

This is pretty awesome! Excellent finds!

[JohnJ]

55 minutes ago, will stevenson said:

Thanks  How should I tell the difference

 

A little research and consideration of the probabilities there are more catfish than stingrays found in a freshwater creek. 

 

Check out the pectoral spines on the Roll videos.

[digit]

We get lots of catfish (and other fish) spines--both pectoral and dorsal--at the Montbrook site. This site is assumed to be fresh or brackish water likely near the coast at the time (5.5 Ma). The pectoral spines are asymmetrical at the base (the dorsal being midbody is completely symmetrical). The catfish ones have wicked barbs on the concave surface whereas the ones from other species are unarmed.

 

Many catfish spines of extant species seem to be barbed on two edges (easy to see in an internet image search) making them more similar to the stingray tail barbs which have recurved barbs on both lateral edges. Stingray spines also tend to be wider and flatter than any fish spines I've seen which are awl shaped and generally a bit recurved. I'd suspect that the barbs are more symmetrical and even sized on stingrays (the tail spine being a midline element) than the dorsal/pectoral spines of fishes.

 

In the paper on the fossils described from Cookiecutter Creek catfish spines were not noted (though they could be there). That site seems to be pretty exclusively marine in nature--but, of course, there are saltwater catfishes.

 

Likely all of Will's barbed spines are stingray but as John points out you always have to consider dorsal/pectoral fish spines which can be very similar.

 

 

Cheers.

 

-Ken

[JohnJ]

3 hours ago, will stevenson said:

13. ray spines

 

 

@digit

Many of these appear asymmetrical.  

[Nimravis]

Nice stuff Wiil,  @Monica did you right.

[sixgill pete]

Great stuff Will. @JohnJ I'm going to have to disagree with you on this one. I believe they are all stingray.

[digit]

Only from my experience with this locality (and not seeing fish spines the way I do with Montbrook micro-matrix) I too believe they are stingray tail barbs. Another clear photo with the specimens lined up for a good view would be useful.

 

All of the other finds are simply gravy as the Isistius triangulus is the real headliner at this site. The only other locality which may come close to the density of this species in micro-matrix is a site from Panama where this species was one of the most common micro-chondrichthyan fossils. It's still a complete mystery why these have been reported from only this one site and no other in the state (and Florida is known to be virtually paved with shark teeth).

 

I'm glad that Will got some nicely complete specimens. Like any other fragile shark teeth there are more fragmented specimens than complete ones found.

 

 

Cheers.

 

-Ken

[JohnJ]

I will defer to the locals if they are split or barbed on both sides.  

[Notidanodon]

2 hours ago, digit said:

Only from my experience with this locality (and not seeing fish spines the way I do with Montbrook micro-matrix) I too believe they are stingray tail barbs. Another clear photo with the specimens lined up for a good view would be useful.

 

All of the other finds are simply gravy as the Isistius triangulus is the real headliner at this site. The only other locality which may come close to the density of this species in micro-matrix is a site from Panama where this species was one of the most common micro-chondrichthyan fossils. It's still a complete mystery why these have been reported from only this one site and no other in the state (and Florida is known to be virtually paved with shark teeth).

 

I'm glad that Will got some nicely complete specimens. Like any other fragile shark teeth there are more fragmented specimens than complete ones found.

 

 

Cheers.

 

-Ken

Hi ken, 

Im happy with the isitius teeth as well, i got another nice one picking through the matrix which ill post tomorrow, one site id like to add is Bonpas, France, they are fairly common there  

i also wonder why they densely locate there, id love to know why the cluster to such an extent

i will get another pick of the barbs tomorrow, i believe them all to be stingray as well  it would make a lot of sense if they are sting rays as the presence of isitius (A deep sea species) would probably suggest it wasnt a brackish environment.

all the best

will

[digit]

2 minutes ago, will stevenson said:

one site id like to add is Bonpas, France, they are fairly common there

I am familiar with that site. Those are also the Isistius triangulus and not the earlier Eocene Isistius trituratus.

 

I have picked some micro-matrix from that locality and found a few broken and one complete tooth. I also received some complete specimens in the trade and all of them were donated to the FLMNH collection as comparative material. It is my understanding that they are relatively common at Bonpas but that the preservation is not very good so that complete teeth are significantly more rare--mainly detached blades without roots.

 

I've heard that processing down the bulk matrix which must be concentrated much more than from CC Creek is possibly largely responsible for the poorer condition of these teeth. In Florida, the creek winnows away the sandy component of the formation whereas at Bonpas the material is collected directly out of the formation and sifting out the finer sand to concentrate the gravely matrix does a real number on these fragile teeth.

 

9 minutes ago, will stevenson said:

i also wonder why they densely locate there, id love to know why the cluster to such an extent

And so would I Will--so would I.

 

It turns out a handful of additional rare micro-chondrichthyan teeth occur in CC Creek that are rarely (if ever) found in other localities in the state. The Montbrook site where the FLMNH has been digging for the last 5 years is the only site that I know of to come close to matching CC Creek.

 

 

Cheers.

 

-Ken