Salubrity Posted June 25, 2019 Share Posted June 25, 2019 Hello! I recently found this well-worn shark’s tooth on a beach in Rehoboth Beach, Delaware. The serrated edges of the tooth are worn down but still visible, although it’s difficult to observe in the photos. I was wondering if anyone has any thoughts as to what species the tooth could possibly belong to? Thank you so much! Take care- Link to comment Share on other sites More sharing options...
PaleoNoel Posted June 25, 2019 Share Posted June 25, 2019 Looks like it might be a great white shark tooth based on the shape and the worn serrations. Link to comment Share on other sites More sharing options...
Darktooth Posted June 25, 2019 Share Posted June 25, 2019 I have never heard of sharkteeth being found from this location. I am not familiar with what exposures are within the vicinity. That being said, the shape does lead me to agree with Great white being a possibility. But because of the size and unknown exposure it came from it could possibly be from Paleocarcharadon. I like Trilo-butts and I cannot lie. Link to comment Share on other sites More sharing options...
Shellseeker Posted June 25, 2019 Share Posted June 25, 2019 Yes, Great White. Here are a couple of my small ones. I can visualize your tooth being a GW. Hard for me to think of any other shark that might own these teeth. The White Queen ".... in her youth she could believe "six impossible things before breakfast" Link to comment Share on other sites More sharing options...
Salubrity Posted June 25, 2019 Author Share Posted June 25, 2019 Thank you all... There is beach erosion, naturally... however the day I found the tooth was a few days after a major storm with high seas and winds. I am an avid seaglass collector and always look for “treasures”... I was standing in a bed of stones and shells deposited by the high tide and honestly thought the tooth was a broken shell at first. I have been here since a babe and have never found a tooth... but I believe I saw on this forum someone found a larger tooth in Bethany Beach (few miles South). The Chesapeake yields a few Snaggletooth shark teeth which we were wondering if this guy was as well. Pretty cool and I’m just super honored to have found this tooth! Appreciate it! Link to comment Share on other sites More sharing options...
Miocene_Mason Posted June 26, 2019 Share Posted June 26, 2019 Given the location I would suspect the specimen is no older than Pleistocene in age, unless it was dropped there by accident. “...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 Link to comment Share on other sites More sharing options...
Salubrity Posted June 26, 2019 Author Share Posted June 26, 2019 Awesome! You all rock!!! thank you so much... Link to comment Share on other sites More sharing options...
caldigger Posted June 26, 2019 Share Posted June 26, 2019 58 minutes ago, WhodamanHD said: Given the location I would suspect the specimen is no older than Pleistocene in age, unless it was dropped there by accident. "The 'ol hole in the pocket routine!" Link to comment Share on other sites More sharing options...
hemipristis Posted June 26, 2019 Share Posted June 26, 2019 12 hours ago, Salubrity said: Hello! I recently found this well-worn shark’s tooth on a beach in Rehoboth Beach, Delaware. The serrated edges of the tooth are worn down but still visible, although it’s difficult to observe in the photos. I was wondering if anyone has any thoughts as to what species the tooth could possibly belong to? Thank you so much! Take care- On Rehoboth Beach? Been going there for 40 years and never saw a fossil there. Good show! Looks like a great white. Could be Holocene, Pleistocene, or even Pliocene. Makes sense though. Sediments of the Miocene-Pliocene subcrop in a swath from Smyrna down to the southern state boundary (e.g., Delmar and Fenwick). Where the river or ocean incise down through the surficial Pleistocene sands, this would expose older material underneath. 'Those who cannot remember the past are condemned to repeat it.' George Santayana Link to comment Share on other sites More sharing options...
Plax Posted June 26, 2019 Share Posted June 26, 2019 What's found on the beach washes out, not up; in my humble opinion. Beach renourishment brings a lot of material onto the shore which is then winnowed and concentrated by wave action. During the last sea level low stand, only thousands of years ago, Rehoboth Beach was an upland. Rivers eroding through the sediments described by Hemipristis deposited fossils off shore. The offshore sediments were pumped onshore to replenish the beach. A future analogy might be a 100 ft sea level rise. The beach would then be inland near Washington DC (guessing). The beach goers have the beach renourished and they get what is found at Calvert Cliffs on their beach. Link to comment Share on other sites More sharing options...
hemipristis Posted June 26, 2019 Share Posted June 26, 2019 2 hours ago, Plax said: What's found on the beach washes out, not up; in my humble opinion. Beach renourishment brings a lot of material onto the shore which is then winnowed and concentrated by wave action. During the last sea level low stand, only thousands of years ago, Rehoboth Beach was an upland. Rivers eroding through the sediments described by Hemipristis deposited fossils off shore. The offshore sediments were pumped onshore to replenish the beach. A future analogy might be a 100 ft sea level rise. The beach would then be inland near Washington DC (guessing). The beach goers have the beach renourished and they get what is found at Calvert Cliffs on their beach. Renourishment is definitely a possibility; a probability even. While reworking and onshore sediment transport also occur, something brought down the Delaware from points North, where the subcrops are shallower are more likely, if it was naturally deposited. 'Those who cannot remember the past are condemned to repeat it.' George Santayana Link to comment Share on other sites More sharing options...
Plax Posted June 26, 2019 Share Posted June 26, 2019 Around here at least the sandy ocean beaches that aren't renourished only have sand clast sized sediment and no shark teeth, gravel etc. Myrtle Beach finds are mostly from renourishment also as the finds disappear once the ocean re-sorts clasts where they belong. The Atlantic is transgressing the shore there though where the Peedee and it's neogene lag on top are at or near current sea level. Without a rocky exposure right at the beach I'd suggest that most of the abundant finds there are from renourishment. I was a fossil hound dog in my youth and never saw a shark tooth at sandy Cape Henlopen or Indian river inlet in Delaware either. Don't remember the name of the famous Miocene site near Dover but it was well below the surface in a pit across from the NJ Miocene outcrop. Some very low Miocene outcrop on the Jersey side in the upper Delaware Bay produced teeth in the 1800s or early 1900s. Still with Rehoboth Beach being about 300 feet above sea level 12,000 years ago I can't see clasts from that outcrop eroding and being transported by the Delaware River, then defying gravity to migrate to the current beach. This suggests a nearby source. Am thinking that someone on this forum mentioned the neogene (Pleistocene?) shell deposits from Dagsboro DE. Similar shell beds could have been eroded and larger clasts concentrated near shore or are even exposed nearshore where the dredge pipes picked up larger clasts along with the sand for renourishment. Link to comment Share on other sites More sharing options...
hemipristis Posted June 27, 2019 Share Posted June 27, 2019 7 hours ago, Plax said: Around here at least the sandy ocean beaches that aren't renourished only have sand clast sized sediment and no shark teeth, gravel etc. Myrtle Beach finds are mostly from renourishment also as the finds disappear once the ocean re-sorts clasts where they belong. The Atlantic is transgressing the shore there though where the Peedee and it's neogene lag on top are at or near current sea level. Without a rocky exposure right at the beach I'd suggest that most of the abundant finds there are from renourishment. I was a fossil hound dog in my youth and never saw a shark tooth at sandy Cape Henlopen or Indian river inlet in Delaware either. Don't remember the name of the famous Miocene site near Dover but it was well below the surface in a pit across from the NJ Miocene outcrop. Some very low Miocene outcrop on the Jersey side in the upper Delaware Bay produced teeth in the 1800s or early 1900s. Still with Rehoboth Beach being about 300 feet above sea level 12,000 years ago I can't see clasts from that outcrop eroding and being transported by the Delaware River, then defying gravity to migrate to the current beach. This suggests a nearby source. Am thinking that someone on this forum mentioned the neogene (Pleistocene?) shell deposits from Dagsboro DE. Similar shell beds could have been eroded and larger clasts concentrated near shore or are even exposed nearshore where the dredge pipes picked up larger clasts along with the sand for renourishment. Anyways, the famous Miocene site is the Pollock's Farm site. It was 30 feet below ground surface if memory serves. They came across it while excavating an area for wetlands mitigation. The Delaware Geological Survey has a very nice free, downloadable report on ntheir website. Very interesting finds and worth checking out. I was working w/ the state in the years preceding, and moved away a year before its discovery. It would have been nice to get in there 'Those who cannot remember the past are condemned to repeat it.' George Santayana Link to comment Share on other sites More sharing options...
Plax Posted June 27, 2019 Share Posted June 27, 2019 Your memory serves you better than mine does me! I have a paper copy of that report or a similar NMNH report and a tiny locality assemblage from a friend that worked the site with the Smithsonian personnel. Link to comment Share on other sites More sharing options...
non-remanié Posted June 28, 2019 Share Posted June 28, 2019 Good discussion. But a big problem with the Delaware River theory is that in the coastal plain section it is not currently incising a channel at all. Its widening by flooding low areas and filling everything in with fine sediments, ending in a bay, an expanding muddy estuary. This has been ongoing since the beginning of the end Pleistocene transgression. Also, in the near shore marine setting off of Rehobeth Beach there would have been very little net sedimentation since the beginning of the transgression. Sands mostly originating from the transgressed land surface are being heavily reworked and sorted with fine material removed out to sea. I believe nourishment is a possibility but also don't see any reason why there aren't a few Holocene and reworked Pleistocene fossils mixed in naturally. 1 ---Wie Wasser schleift den Stein, wir steigen und fallen--- Link to comment Share on other sites More sharing options...
non-remanié Posted June 28, 2019 Share Posted June 28, 2019 I agree that the Pollack Farm book is excellent and I recommend it to anyone studying the miocene of Calvert or NJ. I just checked my copy and the site was the 2nd deepest excavation ever in Delaware. I didn't see exactly how deep it was. 1 ---Wie Wasser schleift den Stein, wir steigen und fallen--- Link to comment Share on other sites More sharing options...
hemipristis Posted June 28, 2019 Share Posted June 28, 2019 14 hours ago, Plax said: Your memory serves you better than mine does me! I have a paper copy of that report or a similar NMNH report and a tiny locality assemblage from a friend that worked the site with the Smithsonian personnel. There's an outcrop of Miocene material in the far SW corner of the state that isn't well-known or published. They want to keep it intact. I haven't heard much detail about what was found, but it does contain fossils. Perhaps it's the same site? 'Those who cannot remember the past are condemned to repeat it.' George Santayana Link to comment Share on other sites More sharing options...
Coco Posted June 29, 2019 Share Posted June 29, 2019 On 27/06/2019 at 2:01 AM, hemipristis said: Anyways, the famous Miocene site is the Pollock's Farm site. It was 30 feet below ground surface if memory serves. They came across it while excavating an area for wetlands mitigation. The Delaware Geological Survey has a very nice free, downloadable report on ntheir website. Very interesting finds and worth checking out. I was working w/ the state in the years preceding, and moved away a year before its discovery. It would have been nice to get in there Would you give us the link please ? I can't find it... Thanks Coco ---------------------- OUTIL POUR MESURER VOS FOSSILES : ici Ma bibliothèque PDF 1 (Poissons et sélaciens récents & fossiles) : ici Ma bibliothèque PDF 2 (Animaux vivants - sans poissons ni sélaciens) : ici Mâchoires sélaciennes récentes : ici Hétérodontiques et sélaciens : ici Oeufs sélaciens récents : ici Otolithes de poissons récents ! ici Un Greg... Link to comment Share on other sites More sharing options...
non-remanié Posted June 29, 2019 Share Posted June 29, 2019 That's probably because he accidentally misspelled it (; https://www.dgs.udel.edu/publications/sp21-geology-and-paleontology-lower-miocene-pollack-farm-fossil-site-delaware 55 minutes ago, Coco said: Would you give us the link please ? I can't find it... Thanks Coco ---Wie Wasser schleift den Stein, wir steigen und fallen--- Link to comment Share on other sites More sharing options...
Coco Posted June 29, 2019 Share Posted June 29, 2019 Thanks a lot Coco ---------------------- OUTIL POUR MESURER VOS FOSSILES : ici Ma bibliothèque PDF 1 (Poissons et sélaciens récents & fossiles) : ici Ma bibliothèque PDF 2 (Animaux vivants - sans poissons ni sélaciens) : ici Mâchoires sélaciennes récentes : ici Hétérodontiques et sélaciens : ici Oeufs sélaciens récents : ici Otolithes de poissons récents ! ici Un Greg... Link to comment Share on other sites More sharing options...
Plax Posted July 1, 2019 Share Posted July 1, 2019 On 6/27/2019 at 11:21 PM, hemipristis said: There's an outcrop of Miocene material in the far SW corner of the state that isn't well-known or published. They want to keep it intact. I haven't heard much detail about what was found, but it does contain fossils. Perhaps it's the same site? I think that one is in the headwaters of the Choptank or one of those SW draining rivers. Most are sections low gradient that far down on delmarva. The site, if it's the same one, is in the Maryland Geological Survey (or USGS?) book on the Miocene. Am thinking the author is William Bullock Clark but could be wrong. Using memory here at work without references. Pollack Farm is the site I have the assemblage and book from. Link to comment Share on other sites More sharing options...
Plax Posted July 1, 2019 Share Posted July 1, 2019 On 6/27/2019 at 10:38 PM, non-remanié said: Good discussion. But a big problem with the Delaware River theory is that in the coastal plain section it is not currently incising a channel at all. Its widening by flooding low areas and filling everything in with fine sediments, ending in a bay, an expanding muddy estuary. This has been ongoing since the beginning of the end Pleistocene transgression. Also, in the near shore marine setting off of Rehobeth Beach there would have been very little net sedimentation since the beginning of the transgression. Sands mostly originating from the transgressed land surface are being heavily reworked and sorted with fine material removed out to sea. I believe nourishment is a possibility but also don't see any reason why there aren't a few Holocene and reworked Pleistocene fossils mixed in naturally. A great elaboration and clarification of what I was saying. thanks! Link to comment Share on other sites More sharing options...
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