Lemon or black tip or ??? Shark teeth ernst quarry

[Allosaurus]

Are these lemon shark teeth? Or black tip? Or something else entirely? How do you tell the difference between lemon and black tip shark teeth? These are from the temblor formation, slow curve ernst quarry. 

[hemipristis]

6 hours ago, Allosaurus said:

Are these lemon shark teeth? Or black tip? Or something else entirely? How do you tell the difference between lemon and black tip shark teeth? These are from the temblor formation, slow curve ernst quarry. 

They are Carcharhinus sp. teeth, but not lemon shark, as it wasn't around yet.  Let me dig to see which Carcharhinus teeth are found there.

[hemipristis]

ok, according to the Buena Vista Museum (LINK: http://www.sharktoothhill.org/index.cfm?fuseaction=news_full_view&news_id=12), two Carcharhinus species are recognized in the fauna: 

1. Carcharhinus cf. egertoni (Agassiz, 1843) (requiem shark)
2. Carcharhinus cf. limbatus (Valenciennes, 1839) (blacktip shark)

The largest Blacktip teeth are smaller than C. ergotoni.  Characteristics of their upper teeth;

• Narrow, erect cusps with little inclination;
• They are taller (i.e., crown height) than they are wide (i.e., root lobe width);
• Finely serrate with some coarsening on the shoulders

I'd posit that the three teeth from the 6o'clock to 9 o'clock positions in your photo are likely candidates, without seeing them in person. Could you take a photo of the labial side?

 

The three largest teeth are C. ergotoni.  The tiny tooth at the top is a lower tooth.  I can't see much detail, but based upon its size, it's either a blacktop lower or a juvenile ergotoni lower.

[Allosaurus]

Thank you so much for helping!

 

Hmmm, so when did the lemon shark appear? On the ID handout he gave us, there is a lemon shark mentioned and I'm pretty sure I heard him mention seeing a lemon tooth that day. However if it isn't present in this formation that would make sense why I never saw it listed on the elasmo site. 

 

 

In the second photo, I have the little tooth magnified with my hand lens. No serrations from what I can see, but he is pretty small to. The other 2 photos afterward are magnified views of 2 different teeth's edges. I see serrations in one but not the other. Would that make the non serrated one C. limbatus?

 

2nd to last photo is part of the ID sheet we were given in the field. Would that make the tooth shown a C. limbatus then instead? The final pic is of other teeth that I had attributed to being lemons based on the ID sheet. 

[hemipristis]

Those photos really helped, thanks.  I'm sticking with my initial assessment.  In addition, it would appear that the really tiny tooth is a blacktop lower. Please find below a photo from elasmo.com of a recent C. limbatus (blacktip shark).  I believe you'll notice the similarities immediately..

 

In regards to the bottom set of 5 teeth, they are all Carcharhinid lowers,  As if the uppers of this genus weren't difficult to identify, the lower are a headache in waiting.  However, C. limbatus lowers have two characteristics which make it easier to ID them sometimes over others of the genus. Both of these traits you can observe in the lower teeth on the extant photo;

 

1. They too tend to be taller than they are wide;
2. They are often inclined lingually (the surface that you are showing here); i.e., if you were to view them in profile view, they would be less erect, and point/tilt lingually.  

I'd say that all are good candidates. Check them in profile view and look for the inward tilt and please report back what you find.  I'm curious!

 

[caldigger]

Geepers!  Rob never gave me an identification chart! 

[hemipristis]

In regards to 'lemon sharks (', they are know from the middle Miocene onward, in the Atlantic and Mediterranean.  They later spread out to the Pacific and Indian Oceans.  Wikipedia, foe what that's worth, says the Eocene, but the peer-reviewed sources are in agreement on mid-Miocene.  

 

Anyways, the Temblor Formation in which these teeth were found is thought to be Late Oligocene to Mid-Miocene.  It's therefore tunlikely that the genus is present here.  

 

What's interesting about the photo in the guide is that while I believe it is a lemon (Negaprion sp.), look at the color. That is not the usual preservation of teeth from this locality.  That's more East Coast.

[ynot]

2 hours ago, hemipristis said:

What's interesting about the photo in the guide is that while I believe it is a lemon (Negaprion sp.), look at the color. That is not the usual preservation of teeth from this locality.  That's more East Coast.

I have dug teeth at the ernst quarries that have that color, rare but there.

 

2 hours ago, hemipristis said:

the Temblor Formation in which these teeth were found is thought to be Late Oligocene to Mid-Miocene.

The "bone bed" at the slow curve site is dated to about 14 million and  considered mid miocene.

[hemipristis]

8 hours ago, ynot said:

I have dug teeth at the ernst quarries that have that color, rare but there.

 

Good to know!  Never had the chance to collect there.  Thank you for noting this. It's always good to have ppl who have actually collected at these sites add their input

[Allosaurus]

On 6/10/2019 at 6:40 AM, caldigger said:

Geepers!  Rob never gave me an identification 

I didn't even know there were ID sheets until I saw someone else with one, so I asked for a copy. 

 

 

@hemipristis I have looked over all the lower teeth and they do indeed match your description of C. limbatus lowers.

 

Thank you everyone for your help! Ill be posting pics of all my teeth in the fossil trips thread soon. 

[caldigger]

On 6/10/2019 at 6:51 AM, hemipristis said:

What's interesting about the photo in the guide is that while I believe it is a lemon (Negaprion sp.), look at the color. That is not the usual preservation of teeth from this locality.  That's more East Coast.

The teeth you get on the other side of the Kern River in the same general vicinity are almost all colored like that of the Lemon Shark sample in your flyer and other colors. The normal blonde/beige teeth that the Ernst Quarry contains is actually the rarity there.

For example:

[siteseer]

On 6/10/2019 at 5:22 PM, hemipristis said:

 

Good to know!  Never had the chance to collect there.  Thank you for noting this. It's always good to have ppl who have actually collected at these sites add their input

 

Yes, you can collect teeth that color from the locality known as the "Whale Quarry" which was once part of the Ernst property - now owned by a different family.

 

One hundred years ago, the Round Mountain Silt was considered to be a member of the Temblor Formation but the regional stratigraphy was reviewed and the whole formation was named the Round Mountain Silt (proposed in the 30's, adopted in the early 40's).  This was reviewed further (Addicott, 1970, Bartow and McDougall, 1984) with the Round Mountain Silt confirmed as the valid name.  There is a Temblor Formation but it has been recognized as a distinct unit exposed several miles to the north.  The Temblor is considered to be around the same age.

 

What causes confusion is that even in the past 10-20 years some paleontologists refer to older papers without consulting more recent reviews of the geology so they use the old names.

 

The Sharktooth Hill Bonebed has been dated as Middle Miocene for decades.  You'd have to tell me which publication says it could be as old as Late Oligocene.

 

Lemon shark teeth of modern form have been collected from the Middle Miocene Rosarito Beach Formation near Ensenada, Baja California, Mexico.  That indicates earlier forms.  A geologist once showed me a lemon shark tooth he collected in a layer above the STH Bonebed in Bakersfield.

 

Carcharhinus egertoni is a problematic species.  It's a name based on two syntypes that have been determined to belong to two separate species (C brachyurus and C. leucas).  Also, I'm not aware of any formal review of the Carcharhinus teeth from the bonebed.  Personally, over the years, I've been reluctant to accept C. limbatus as a member of the fauna but some of the teeth are at least very similar. 

 

I'm not sure a paleontologist has reviewed and edited the faunal list from the Buena Vista Museum because there are more than two Carcharhinus tooth types - more than two apparent species - in the STH fauna.  You should know that teeth very similar to C. obscurus have been found in the bonebed.  They are rare but their broad crowns stick out among the more narrow-crowned teeth.  

 

Addicott, W.O. 1970.

Miocene gastropods and biostratigraphy of the Kern River area, California. USGS Professional Paper 642. 174 p.

 

Bartow, J.A. and K.A. McDougall. 1984.

Tertiary stratigraphy of the southeastern San Joaquin Valley, California. USGS Bulletin 1529-J. 41 p.

 

 

[Al Dente]

On 6/10/2019 at 9:51 AM, hemipristis said:

In regards to 'lemon sharks (', they are know from the middle Miocene onward, in the Atlantic and Mediterranean.  They later spread out to the Pacific and Indian Oceans.  Wikipedia, foe what that's worth, says the Eocene, but the peer-reviewed sources are in agreement on mid-Miocene.  

 

1 hour ago, siteseer said:

Lemon shark teeth of modern form have been collected from the Middle Miocene Rosarito Beach Formation near Ensenada, Baja California, Mexico.  That indicates earlier forms.  A geologist once showed me a lemon shark tooth he collected in a layer above the STH Bonebed in Bakersfield.

Negaprion probably exist in the Eocene, and Negaprion eurybathodon ( lemon shark) are common in the late Oligocene Belgrade Formation here in North Carolina. They are also found in the lower layers of the Pungo River Formation which might extend into the Oligocene.

 

 Carcharhinus gilmorei, aka Sphyrna gilmorei, aka Negaprion gilmorei is found in the Eocene of the eastern US. Ebersol, Cicimurri and Stringer, 2019, recently placed it back into Negaprion.

[hemipristis]

46 minutes ago, Al Dente said:

Negaprion probably exist in the Eocene, and Negaprion eurybathodon ( lemon shark) are common in the late Oligocene Belgrade Formation here in North Carolina. They are also found in the lower layers of the Pungo River Formation which might extend into the Oligocene.

I have collected several from the Pungo, and have, since the OP in 2019, obtained a few Oligocene examples from the Belgrade from a trusted collector. I never bothered to sort through my previous, historical posts to correct myself.  

 

 

46 minutes ago, Al Dente said:

 Carcharhinus gilmorei, aka Sphyrna gilmorei, aka Negaprion gilmorei is found in the Eocene of the eastern US. Ebersol, Cicimurri and Stringer, 2019, recently placed it back into Negaprion.

 

I did some digging online after I read your post, and it would seem that there are conflicting opinions on not only to which genus the gilmorei teeth, but whether they are Oligocene or Eocene.

 

 

 

 

 

 

 

 

 

Edited November 7, 2022 by hemipristis

[Al Dente]

11 minutes ago, hemipristis said:

Any references to Negaprion in the Eocene?

 

 

[hemipristis]

Just now, Al Dente said:

 

 

thanks

[hemipristis]

2 hours ago, siteseer said:

 

Yes, you can collect teeth that color from the locality known as the "Whale Quarry" which was once part of the Ernst property - now owned by a different family.

 

One hundred years ago, the Round Mountain Silt was considered to be a member of the Temblor Formation but the regional stratigraphy was reviewed and the whole formation was named the Round Mountain Silt (proposed in the 30's, adopted in the early 40's).  This was reviewed further (Addicott, 1970, Bartow and McDougall, 1984) with the Round Mountain Silt confirmed as the valid name.  There is a Temblor Formation but it has been recognized as a distinct unit exposed several miles to the north.  The Temblor is considered to be around the same age.

 

What causes confusion is that even in the past 10-20 years some paleontologists refer to older papers without consulting more recent reviews of the geology so they use the old names.

 

The Sharktooth Hill Bonebed has been dated as Middle Miocene for decades.  You'd have to tell me which publication says it could be as old as Late Oligocene.

 

Lemon shark teeth of modern form have been collected from the Middle Miocene Rosarito Beach Formation near Ensenada, Baja California, Mexico.  That indicates earlier forms.  A geologist once showed me a lemon shark tooth he collected in a layer above the STH Bonebed in Bakersfield.

 

Carcharhinus egertoni is a problematic species.  It's a name based on two syntypes that have been determined to belong to two separate species (C brachyurus and C. leucas).  Also, I'm not aware of any formal review of the Carcharhinus teeth from the bonebed.  Personally, over the years, I've been reluctant to accept C. limbatus as a member of the fauna but some of the teeth are at least very similar. 

 

I'm not sure a paleontologist has reviewed and edited the faunal list from the Buena Vista Museum because there are more than two Carcharhinus tooth types - more than two apparent species - in the STH fauna.  You should know that teeth very similar to C. obscurus have been found in the bonebed.  They are rare but their broad crowns stick out among the more narrow-crowned teeth.  

 

 

 

 I was a bit surprised to see responses to a post from 2019, I must admit. Unfortunately, I do not recall which publication I used at the time. I should have referenced it.

Since my OP in this thread, I. have been collecting references on Neogene teeth, and expended more time than I'm willing to admit trying to familiarize myself with, and distinguishing between, teeth ascribed from the genus Carcharhinus.  I concur with your statement re: C. egertoni.  For some time since my OP, I have arrived at the opinion that C. egertoni and C. gibbesi have some problems. IMHO, they appear to have been used as "catch-alls" by some.

 

I have little doubt that there are more than 2 Carcharhinus species present in the fauna, given the diversity in mid-Miocene strata elsewhere.  I wish I could collect there. But alas, I have to do it via the silver pick, haha. 

 

I'd be greatly interested in seeing pictures of the "broad crown" teeth you mention in your last sentence.  I wonder, could they be C. galapagensis?  C longimanus?

 

Edited November 7, 2022 by hemipristis