Miocene Shark, Ray And Fish Micros From The Ernst Ranch Bakersfield California

[MarcoSr]

I want to thank Doren for sending me matrix from the Miocene, Round Mountain Silt, Sharktooth Hill Fauna from the Ernst Ranch in Bakersfield, California. I received a medium USPS flat rate box of raw matrix. I soaked the matrix in hot water for several hours and then washed it with water using a .4mm sieve to catch the really small teeth. I wound up with around 3 cups of matrix to search. I’m posting some of the nicer specimens that I found in the matrix. There were a high number of nice conditioned shark and ray specimens, some fish teeth and a mammal tooth in the matrix. Most of the teeth are very light colored so I took the pictures with a black background. Taking pictures with a black background is a lot more difficult and takes more time so I usually use white backgrounds if I can.

If you place your cursor on a JPEG image you will see the file name which will have the specimen id as best that I can determine and the specimen size. These specimens were in the .5mm to 10mm size range. Each matrix that I search makes me more of an avid micro tooth collector. If anyone has or can collect good matrix with shark, ray, and fish micros please send me a PM.

Some of the nicer shark teeth:

Carcharhinus:

Cetorhinus teeth, several teeth with a single cusplet, and a gill raker. Teeth with a single cusplet are not common. These are the first that I have found from the Ernst Ranch. I have several from Ant Hill. These will be addressed shortly in the literature.:

Galeocerdo:

Galeorhinus:

Heterodontus:

A small Mako:

Mustelus:

I misidentified this tooth once already but I believe it is a Physogaleus symphyseal. The tooth is serrated:

Continued in the next reply.

Marco Sr.

Edited December 27, 2013 by MarcoSr

[MarcoSr]

Squalus:

Squatina:

Triakis:

Some of the nicer ray teeth:

Dasyatis:

Gymnura:

Mobula:

Myliobatis lateral teeth:

Raja, which are pretty rare from Bakersfield. I had only found two before and I have looked through a lot of fine .5mm to 1mm Bakersfield matrix:

Continued in the next reply.

Marco Sr.

Edited December 27, 2013 by MarcoSr

[MarcoSr]

Rhinobatos:

Dermal scutes:

Dermal Denticle:

I only found a small number of fish teeth:

I found a single damaged mammal tooth:

I’m not really sure what this is: Edit fish pelvic girdle per Tony

Marco Sr.

Edited November 21, 2015 by MarcoSr

[John Hamilton]

Great report and great photos Marco! I got a flat rate box from Doren also. I have been through about half of it and found many well preserved specimens. I manged to find a small marine mamal tooth and what looks like a small terrestrial mamal tooth in a section of jawbone.

[busyeagle]

Great work as usual Marco.

[masonboro37]

WOW! Awesome specimens and pictures too! Thank you so much for sharing. Love the Rhinobatos dermal denticle and all of it!

Libby

[Terphunter]

Cool!

[Scylla]

Nice, what is the scale of these?

[jcbshark]

Awesome finds Marco,I love the little Mako and the Cetorhinus teeth!

[Pagurus]

Thanks for sharing your great photos, and ID's too. I'm finding that searching through micros is really addicting!

Mike

[siteseer]

Marco Sr.,

That fifth Heterodontus tooth is a nice example of an adult anterior. It has a broader-based crown and has nearly lost its cusplets. You tend to find more juvenile teeth (narrower crowns with well-developed cusplets) in the STH bonebed. Your specimens also have better-than-average roots.

Jess

Heterodontus:

Heterodontus sp.1 8mm.jpgHeterodontus sp.2 2mm.jpgHeterodontus sp.3 2.5mm.jpgHeterodontus sp.4 5mm.jpgHeterodontus sp.5 3mm.jpg

[siteseer]

I remember you discussing the distinguishing characters of Raja and Dasyatis from another locality in another thread. Some Raja teeth look a lot like the more cuspidate-type Dasyatis teeth. I've seen so few STH Raja teeth that I shouldn't make general statements about them but I will say the two I have look like that one (though I have a couple of oddball ray teeth that might be another rajid form). They differ from most cuspidate Dasyatis teeth in that they are generally smaller (1-2mm), though there is also a smaller Dasyatis in that size range, and the crown is smooth. Dasyatis crowns tend to have some ornamentation. In Raja the root widens toward its base and is more weakly bilobate than Dasyatis. The root lobes are more clearly prong-like in Dasyatis.

Jess

Raja, which are pretty rare from Bakersfield. I had only found two before and I have looked through a lot of fine .5mm to 1mm Bakersfield matrix:

Raja sp.1 1mm.jpgRaja sp.2 1mm.jpg

[siteseer]

Yeah, that mammal tooth looks like the smallest form of STH dolphin.

I'm stumped by that last specimen. If you are accepting guesses, it looks like a bony fish dermal spine but may be from a ray.

Jess

I found a single damaged mammal tooth:

Mammal tooth 10mm.jpg

I’m not really sure what this is:

Unknown1 1.5mm.jpg

Marco Sr.

[MarcoSr]

Great report and great photos Marco! I got a flat rate box from Doren also. I have been through about half of it and found many well preserved specimens. I manged to find a small marine mamal tooth and what looks like a small terrestrial mamal tooth in a section of jawbone.

John

The matrix from Doren is probably the best matrix that I have looked through from the Ernst Ranch including matrix that I collected myself. Doren was really in the good bone bed when he took it. I look forward to your post, especially seeing the terrestrial mammal tooth.

Marco Sr.

[MarcoSr]

WOW! Awesome specimens and pictures too! Thank you so much for sharing. Love the Rhinobatos dermal denticle and all of it!

Libby

Libby

I really like the dermal denticle also. They can be extremely intricate and very delicate.

Marco Sr.

[MarcoSr]

Nice, what is the scale of these?

The specimens range in size from .5mm to 10mm. If you place your cursor on a JPEG image you will see the file name which will have the specimen id and size.

Marco Sr.

[MarcoSr]

Awesome finds Marco,I love the little Mako and the Cetorhinus teeth!

Jeff

Cetorhinus are very common in Bakersfield but really rare worldwide, just like the cookie cutters in your creek being common but pretty rare worldwide.

Marco Sr.

[MarcoSr]

Thanks for sharing your great photos, and ID's too. I'm finding that searching through micros is really addicting!

Mike

Searching matrix for me is very relaxing and lets me fossil hunt in places all over the world that I'll never get to in person. We need more people addicted to searching matrix for micros because that is where a lot of new family/genus/species of sharks and rays will be found. That is my main reason for doing these posts to interest others in searching matrix for micros.

Marco Sr.

Edited December 28, 2013 by MarcoSr

[MarcoSr]

Great work as usual Marco.

Kyle

When Dr. W and I go into the field to get matrix for his vertebrate studies, you can always join us and collect some for your own searching and posts.

Marco Sr.

[MarcoSr]

Marco Sr.,

That fifth Heterodontus tooth is a nice example of an adult anterior. It has a broader-based crown and has nearly lost its cusplets. You tend to find more juvenile teeth (narrower crowns with well-developed cusplets) in the STH bonebed. Your specimens also have better-than-average roots.

Jess

Jess

I really like STH matrix because Heterodontus are relatively common and are one of my favorite shark genus. I don't find them in any other fauna in such large numbers. I really like the immature teeth with all of the cusps. I took pictures of the more complete specimens with roots. I found others missing the roots.

Marco Sr.

[MarcoSr]

Yeah, that mammal tooth looks like the smallest form of STH dolphin.

I'm stumped by that last specimen. If you are accepting guesses, it looks like a bony fish dermal spine but may be from a ray.

Jess

Jess

Thank you for the mammal tooth id. That unknown was very unusual for me also. I was surprised that I really didn't find a lot of fish material in the matrix compared to the number of ray and shark teeth. I did find various fish teeth but not the fish verts and other fish parts that I see in other faunas. I thought that the unknown might be a fish spine also but it doesn't seem to resemble very closely others that I have from other faunas. I also thought that it might be a very odd gill raker but it doesn't resemble very closely others that I have from other faunas.

Marco Sr.

[MarcoSr]

I remember you discussing the distinguishing characters of Raja and Dasyatis from another locality in another thread. Some Raja teeth look a lot like the more cuspidate-type Dasyatis teeth. I've seen so few STH Raja teeth that I shouldn't make general statements about them but I will say the two I have look like that one (though I have a couple of oddball ray teeth that might be another rajid form). They differ from most cuspidate Dasyatis teeth in that they are generally smaller (1-2mm), though there is also a smaller Dasyatis in that size range, and the crown is smooth. Dasyatis crowns tend to have some ornamentation. In Raja the root widens toward its base and is more weakly bilobate than Dasyatis. The root lobes are more clearly prong-like in Dasyatis.

Jess

Jess

I agree with your observations. I see lots of Raja from VA, NC and SC but have now only seen 4 personally from Bakersfield. What strikes me the most about Raja is the huge variation in both the crown and root design. I just noticed that the two specimens that I posted don't have bilobate roots. However I see a lot of bilobate roots from VA, NC, and SC. The root lobes can be very thick (remind me of little tree trunks) especially in comparison to the rest of the tooth size and really angle to the side with a V or triangular space between them (Dasyatis root lobes tend to be parallel with a U shaped space between them) . However there are also bilobate variations that are closer to the root design in my posted specimens. It is hard for me to identify a tooth from a two dimensional picture a lot of times. I see one view and I think one id. Then see another view and think another id. I saw several small Dasyatis (at least that is what I think they are) in this batch of matrix that I really had to look at in a bunch of views to make an id. I didn't take pictures of these because it is a lot easier to take pictures of the bigger examples and I did have a bit of uncertainty. I just seem to get an impression when I look at a tooth based upon the teeth that I've seen. It then becomes difficult for me to change that impression unless I can see details that just don't fit.

Marco Sr.

Edited December 28, 2013 by MarcoSr

[John Hamilton]

John

The matrix from Doren is probably the best matrix that I have looked through from the Ernst Ranch including matrix that I collected myself. Doren was really in the good bone bed when he took it. I look forward to your post, especially seeing the terrestrial mammal tooth.

Marco Sr.

Hopefully I will be able to post my finds before my vacation is over. I still have half a box of matrix from Doren to go through plus I need to photograph the specimens from the previous batches of matrix that Sacha, jcbshark, and obsessed1 sent me.

[caldigger]

Wow, I am so glad everyone is finding good stuff in the matrix I collected... "IT MAKES A PAPA PROUD"! Some interesting teeth, you take such great photos Marco. It is really nice to see these things without a 20x loupe stuck in one eye (the only way I can see them).

I do make the best effort to seek out the best areas to collect, and it shows. Thanks for posting.

If you want more, I got it. Doren

Edited December 28, 2013 by caldigger

[AncientEarth]

Great resource Marco!

I've been trying to ID a couple cups I have full of these small teeth and I might try and organize them next time I have a min.