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Upper Cretaceous Shark Tooth


MDPaleoceneGeo

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Found this today in creek bed gravel near Bowie Maryland (near Old Crain Drive).   Upper Cretaceous Severn Formation.   Any idea?   Interesting areas of white coloring, between tooth and base?  I know base is missing.  Does anyone know what causes the white banding?

 

 

IMG_2971 - shartk Tooth Severn Formation.JPG

IMG_2972 - shartk Tooth Severn Formation.JPG

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Any serrations? Looks to be an Otodus (washed there from the Aquia FM) or possibly a cretalamna from the Severn FM, 

Cool find. The whiteness could either be from wear via contact with plant roots (they are acidic and corrode away some minerals, these are colloquially called “lightning strikes”) or maybe sun-bleaching. Hard to tell which, though I’m leaning towards lighting strikes at least on the front.

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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8 minutes ago, RyanDye said:

Just to clarify Whodaman is talking about a shark. :meg:

I think he may have known that based on the title of the thread;)

 

I'm gonna tag @MarcoSr to make sure I’m not saying something stupid (I thought meg for a moment but I think it lacks a bourlette)

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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Thanks Mason - thought you may be first to respond.  The Book Rockhounding in Del, MD, DC by Beard - says you can find small shark teeth and crocodile teeth at this location and its Upper Cretaceous Severn Formation.    So I was pretty surprised when I found one this size.  Screened in gravel beds in stream for about 2.5 hours - then finally found something.   No Serrations.  

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42 minutes ago, Don Mullis said:

Cretoxyrhina mantelli?

Maybe, would see more curve I would think but I’ve never actually seen on in person. Marco Sr will know I think when he gets here.

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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1 minute ago, RyanDye said:

My bad 

That’s fine, I’ve done it before many times:D

 

2 hours ago, Don Mullis said:

The Book Rockhounding in Del, MD, DC by Beard - says you can find small shark teeth and crocodile teeth at this location and its Upper Cretaceous Severn Formation. 

Never would have thought a book would mention the Severn formation, it’s relatively obscure and doesn’t expose too much. 

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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10 hours ago, WhodamanHD said:

Maybe, would see more curve I would think but I’ve never actually seen on in person. Marco Sr will know I think when he gets here.

 

If the site is the one that I'm familiar with, there is only Cretaceous there, no other time periods.  A lot of sifting and digging took place years ago at this site.  People that know the area don't go back because the good areas have been sifted/dug out.  The teeth coming out of the Severn Formation lag layers are black like this specimen.  This crown is small so there are a good number of possibilities for an id.  Unfortunately, from pictures of just a crown of a heavily reworked tooth, I can't give a probable id.

 

Marco Sr.. 

"Any day that you can fossil hunt is a great day."

My family fossil website     Some Of My Shark, Ray, Fish And Other Micros     My Extant Shark Jaw Collection

image.png.9a941d70fb26446297dbc9dae7bae7ed.png image.png.41c8380882dac648c6131b5bc1377249.png

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Thanks Marcosr.   Yes Cretaceous - I am old geologist who likes fossil hunting.  Found in gravel which I was screening.  Same location as historically published.  A nice spot also for Siderite concretions.  I got one a perfect bollowing ball shape.  Disappointed no crown on tooth.  Maybe new areas washed out into gravel.  Do you know exactly what layer they are coming from.  Monmouth (now severn) is disconfirmity with overlaying Paleocene brightseat and then Paleocene Aquia.  Nice gravel in some spots.  I think the gravel may be Pleistocene.  So no Aquia here. Unless gravel is from Paleocene? In other spots I only see a orange silt/sand contact.   Assume then the teeth are coming from Monmouth (now Severn).   Normally very small so one this large was surprising.  Anyway thanks for responding. 

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16 hours ago, Don Mullis said:

Thanks Marcosr.   Yes Cretaceous - I am old geologist who likes fossil hunting.  Found in gravel which I was screening.  Same location as historically published.  A nice spot also for Siderite concretions.  I got one a perfect bollowing ball shape.  Disappointed no crown on tooth.  Maybe new areas washed out into gravel.  Do you know exactly what layer they are coming from.  Monmouth (now severn) is disconfirmity with overlaying Paleocene brightseat and then Paleocene Aquia.  Nice gravel in some spots.  I think the gravel may be Pleistocene.  So no Aquia here. Unless gravel is from Paleocene? In other spots I only see a orange silt/sand contact.   Assume then the teeth are coming from Monmouth (now Severn).   Normally very small so one this large was surprising.  Anyway thanks for responding. 

 

I never saw evidence of the Aquia Formation at the site but I only collected two specific layers there.  There are two layers in the Severn Formation at the site that produce a good number of teeth that I'm aware of.  The one lag layer has a high fossil concentration of black, heavily reworked teeth.  There are lots of teeth in the layer but the condition is really poor.  I know of only one spot in the area where this layer is exposed but is about 12 feet up in a cliff that is private property.  The owner has only given permission to one person that I'm aware of to dig in his cliff.  However the poor condition of the teeth really doesn't make it worth the effort.  There is another sandy layer a little above stream level that has a good fossil density with high quality teeth.  I went back to the site last year with a good friend who spent a lot of time at the site.  We pretty much checked out the stream in the area looking for this layer.  All the exposures of this layer that were easy to get to have been completely dug out.  You can see in areas overhangs which were caused by collector digging and not stream erosion.  Truthfully a lot of overburden would have to be removed to get to the good layer which would require land owner permission (There are a number of land owners in the area).  Again not worth the effort.  Because of the overgrown banks not a lot of formation gets eroded into the stream.  So the gravel doesn't get a lot of new fossils from erosion.  Parts of that stream were heavily sifted for years so I don't think there is much there either unless you get real lucky and find a small untouched area.  Like a number of other relatively small sites written about in MD, there just isn't much left accessible at the site to collect.

 

Marco Sr.

 

"Any day that you can fossil hunt is a great day."

My family fossil website     Some Of My Shark, Ray, Fish And Other Micros     My Extant Shark Jaw Collection

image.png.9a941d70fb26446297dbc9dae7bae7ed.png image.png.41c8380882dac648c6131b5bc1377249.png

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13 hours ago, MarcoSr said:

 

I never saw evidence of the Aquia Formation at the site but I only collected two specific layers there.  There are two layers in the Severn Formation at the site that produce a good number of teeth that I'm aware of.  The one lag layer has a high fossil concentration of black, heavily reworked teeth.  There are lots of teeth in the layer but the condition is really poor.  I know of only one spot in the area where this layer is exposed but is about 12 feet up in a cliff that is private property.  The owner has only given permission to one person that I'm aware of to dig in his cliff.  However the poor condition of the teeth really doesn't make it worth the effort.  There is another sandy layer a little above stream level that has a good fossil density with high quality teeth.  I went back to the site last year with a good friend who spent a lot of time at the site.  We pretty much checked out the stream in the area looking for this layer.  All the exposures of this layer that were easy to get to have been completely dug out.  You can see in areas overhangs which were caused by collector digging and not stream erosion.  Truthfully a lot of overburden would have to be removed to get to the good layer which would require land owner permission (There are a number of land owners in the area).  Again not worth the effort.  Because of the overgrown banks not a lot of formation gets eroded into the stream.  So the gravel doesn't get a lot of new fossils from erosion.  Parts of that stream were heavily sifted for years so I don't think there is much there either unless you get real lucky and find a small untouched area.  Like a number of other relatively small sites written about in MD, there just isn't much left accessible at the site to collect.

 

Marco Sr.

 

 

 

Hi Marco Sr,

 

I remember talking to collectors who knew about Bowie (this was back in the 90's) and then read an article about it.  The article indicated that the top of the Matawan Formation might be the source for at least some of the more eroded fossils.  The Severn had some decent micros in it.  I have only a few teeth from Bowie so I don't have a lot to say.  I never heard of any Paleocene material from there either.

 

There was some Paleocene stuff (Brightseat Formation) from another construction site open in the 90's that more people in Maryland seemed to know about.  They called the site by the street name in the Largo area if that rings a bell.

 

Jess.

 

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6 hours ago, siteseer said:

 

 

Hi Marco Sr,

 

I remember talking to collectors who knew about Bowie (this was back in the 90's) and then read an article about it.  The article indicated that the top of the Matawan Formation might be the source for at least some of the more eroded fossils.  The Severn had some decent micros in it.  I have only a few teeth from Bowie so I don't have a lot to say.  I never heard of any Paleocene material from there either.

 

There was some Paleocene stuff (Brightseat Formation) from another construction site open in the 90's that more people in Maryland seemed to know about.  They called the site by the street name in the Largo area if that rings a bell.

 

Jess.

 

 

Jess

 

There were two lag layers at this site.  The thin one at stream level which overlays the Matawan Formation had both reworked and pristine teeth.  The second higher layer only had reworked teeth.  I have a good number of micros from the site but a lot are badly reworked.

 

The Largo site is another MD site that really isn't accessible for collecting anymore.  During construction, there were exposures with great Paleocene fossils.  However something was built on the site (I won't say what because it will draw people to the area) that covered up the vast majority of the site.  There is only a very small fenced in area left with "no trespassing" signs all over it.  Another MD site that is no longer available to collect.  In the 1970s I had over 100 sites I could collect in MD and VA.  Now there are only a handful of these sites left.

 

Marco Sr.

"Any day that you can fossil hunt is a great day."

My family fossil website     Some Of My Shark, Ray, Fish And Other Micros     My Extant Shark Jaw Collection

image.png.9a941d70fb26446297dbc9dae7bae7ed.png image.png.41c8380882dac648c6131b5bc1377249.png

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8 hours ago, MarcoSr said:

Now there are only a handful of these sites left.

Ay, there’s the rub.

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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Thanks Marcosr and Jess.   Can anyone provide any papers on shark teeth in the Severn Formation?    I have MGS Upper Cretaceous Plates which their is some info.   Thanks

 

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The Bowie site is in the book "Fossil Collecting in Maryland", no? The Mosasaur, Delaware Valley Paleontological Society journal is available on line. It has a few papers on the subject. (google)

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1 hour ago, Plax said:

The Bowie site is in the book "Fossil Collecting in Maryland", no? The Mosasaur, Delaware Valley Paleontological Society journal is available on line. It has a few papers on the subject. (google)

I’ve heard this site is not viable anymore, no trespassing signs and such.

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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Neglected to quote the reason for my answer, thus:

Can anyone provide any papers on shark teeth in the Severn Formation? 

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5 minutes ago, Plax said:

Neglected to quote the reason for my answer, thus:

Can anyone provide any papers on shark teeth in the Severn Formation? 

Oh sorry:D 

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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This discussion brings back great memories in the late 90's when I collected the Bowie site. Lots of dangerous digging by a stream and sifting but fantastic micro teeth.  My best source back then was Kent's book,  Fossil sharks of the Chesapeake Bay Region where he addresses teeth from the Severn Fm. 

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Thanks everyone - good info.   So here is a recent pic of the site with siderite nodules in the Severn/Matawan Formation.  The Siderite was a characteristic of the upper part of the section as mapped by Glaser (1976) when he described the Monmouth/Matawan Formation (now Severn Formation) in AA Geology Map (PG county location is just off the map - attached).  Per USGS link Monmouth is 

Lithologic constituents
Major
Unconsolidated > Coarse-detrital > SandDark gray to reddish-brown, micaceous, glauconitic, argillaceous, fine- to coarse-grained sand;
Minor
Unconsolidated > Coarse-detrital > Gravelbasal gravel in Prince Georges County
 

So what I hear being said is that the teeth are found in a basal gravel unit (makes sense with description above) which in my pick would be just above the stream level (so contact between the Monmouth and Matawan)?   Assumes I have drawn the contacts correctly.   I don't see any Paleocene above Severn in the pic - just Pleistocene.  So all teeth are Cretaceous.  

Bowie MD Site.JPG

Glaser AA Geo - Monmouth_Matawan.pdf.jpg

IMG_2958.JPG

IMG_2959.JPG

IMG_2960.JPG

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10 minutes ago, MDPaleoceneGeo said:

So what I hear being said is that the teeth are found in a basal gravel unit (makes sense with description above) which in my pick would be just above the stream level (so contact between the Monmouth and Matawan)? 

 

The lag layer with the high density of nice teeth is only in a very localized area along the stream.  Where the layer was you could see a thin sandy band with teeth sticking out.  Some high density fossil contact layers can extend for many miles.  However this one doesn't.  It is absent from most of the contact of the Severn/Matawan Formations along that stream.  At least sampling the contact in a number of other areas along the stream didn't produce much at all.  Where it was exposed, it was dug out years ago.  I see lag layers like this a lot working with Dr. Weems on his vertebrate fauna lists studies.  A lot of the lag layers that we collect are very localized.  These layers get thinner and then disappear.  Some lag layers we dig get thinner and thinner as we dig into the formation and eventually disappear.  Looking at your site picture, I don't see this sandy lag layer at the contact.  PM me if you have further questions.

 

Marco Sr.

"Any day that you can fossil hunt is a great day."

My family fossil website     Some Of My Shark, Ray, Fish And Other Micros     My Extant Shark Jaw Collection

image.png.9a941d70fb26446297dbc9dae7bae7ed.png image.png.41c8380882dac648c6131b5bc1377249.png

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  • 4 weeks later...

Upstream from the collectable Severn area, the Severn was overlaid by a gravel/cobble layer.  In it, I found a few really beat up teeth which appeared to be Eocene in age.

 

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  • 2 weeks later...
On 2/25/2018 at 5:16 PM, MDPaleoceneGeo said:

Thanks Marcosr.   Yes Cretaceous - I am old geologist who likes fossil hunting.  Found in gravel which I was screening.  Same location as historically published.  A nice spot also for Siderite concretions.  I got one a perfect bollowing ball shape.  Disappointed no crown on tooth.  Maybe new areas washed out into gravel.  Do you know exactly what layer they are coming from.  Monmouth (now severn) is disconfirmity with overlaying Paleocene brightseat and then Paleocene Aquia.  Nice gravel in some spots.  I think the gravel may be Pleistocene.  So no Aquia here. Unless gravel is from Paleocene? In other spots I only see a orange silt/sand contact.   Assume then the teeth are coming from Monmouth (now Severn).   Normally very small so one this large was surprising.  Anyway thanks for responding. 

 

On 2/28/2018 at 2:18 PM, MDPaleoceneGeo said:

Thanks everyone - good info.   So here is a recent pic of the site with siderite nodules in the Severn/Matawan Formation.  The Siderite was a characteristic of the upper part of the section as mapped by Glaser (1976) when he described the Monmouth/Matawan Formation (now Severn Formation) in AA Geology Map (PG county location is just off the map - attached).  Per USGS link Monmouth is 

Lithologic constituents
Major
Unconsolidated > Coarse-detrital > SandDark gray to reddish-brown, micaceous, glauconitic, argillaceous, fine- to coarse-grained sand;
Minor
Unconsolidated > Coarse-detrital > Gravelbasal gravel in Prince Georges County
 

So what I hear being said is that the teeth are found in a basal gravel unit (makes sense with description above) which in my pick would be just above the stream level (so contact between the Monmouth and Matawan)?   Assumes I have drawn the contacts correctly.   I don't see any Paleocene above Severn in the pic - just Pleistocene.  So all teeth are Cretaceous.  

 

My understanding is that the Bowie site exposes just the upper Cretaceous Severn Formation, but that as with much of the Coastal Plain, Quaternary aged unconsolidated sediments often lie on an unconformable contact with the "bedrock". That's how it is with the Patuxent Formation near me. 

 

I haven't collected much in any layers overlying the Arundel in the MD Cretaceous, but from what I've gathered from various sources is that there's a gravel bed in the Severn that is somewhat fossiliferous where much of these teeth come from (shells are most common). 
 

There are no post-Cretaceous rocks exposed at the Bowie site, and as such the gravels are part of the Cretaceous Severn Formation, not the Paleocene Brightseat (which is mostly in the southern corner of PG County), Aquia or the Eocene Pamunkey Group. At any rate I don't even know of any significant gravel beds in the Aquia-Pamunkey units except for some armored mud balls in the Marlboro Clay, but those are pretty rare from my understanding (the Marlboro is poorly exposed anyways and doesn't readily crop out). 

 

Sorry I can't help with the teeth though! They certainly look cool, however. 

 

 

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