Ontocetus emmonsi Tusk Fossil
Miocene-Pleistocene (13.6 million years ago to 300,000 years ago)
Example is believed to be from the latter era.
Possible excavation source: North America, Atlantic Northern seaboard, New England
Approximate measurements: 10" x 2" x 1", weight is not given

A fossil discovery from the ocean floor. Enamel shows erosion from salt water. The base of the tusk appears to have been a break from the bone jaw line of the animal, a natural separation. It does not appear to be a broken segment from a longer tusk. This is what makes me believe it is of an ancient walrus; and not a section from a differ ice age creature, like a mammoth. Example was found loose and not embedded in a matrix. No evidence of repair or restoration. It does not appear to have been coated or given polish treatments. The fossil is in it's natural state.

A Tusk is an elongated, modified tooth, like those of elephants. The structure of the tooth includes dentin, pulp and other tissues, blood vessels and nerves embedded in the jaw. Above the gum line, the tooth is protected by the hard enamel covering. Horn and antlers are a keratinous structure growth. They from from the skin and are found in animals like rhinoceroses. Unlike antlers which are shed and regrown annually, tusks are permanent teeth that continue to grow throughout an animal's life, and are not shed. I am able to identify, from images the dentin and enamel structures of you example. It is a positive match to a walrus tusk. Ontocetus (Walruses), both male and female, have tusks, which are actually modified upper canine teeth, that they use for climbing on ice, fighting predators, and engaging in social interactions like threatening and fighting each other.

I am not sure if the excavation source is accurate. Most all fossilized tusk discoveries are from further south along the Atlantic shores of the Carolinas and Florida. I do suggest an in person assessment to help guide you to a more accurate excavation site. It is an excellent example, retain all paperwork and documentation to keep along with the example for future sale and insurance assessment.

Additional reading:
https://www.nytimes.com/2024/08/13/science/walrus-fossil.html

https://www.fisheries.noaa.gov/feature-story/clam-survey-dredges-ice-age-find

https://www.scmuseum.org/learn/deeper-dive-series/fossil-facts-ancient-walrus-tusk-found-south-carolina