The Dorsal Fin

ABC News is reporting that a 300-million-year-old partial shark jaw was recently discovered in a Kentucky mine. Jay Dixon, a mine operator, discovered the fossilized shark jaw in February.

Gerald A. Weisenfluh, the associate director of the Kentucky Geological Survey, says the jawbone is from a shark species of the Edestus genus, which lived during the Carboniferous Period (359.2 – 299 million years ago).

The jaw contains teeth that are 2″ in width at the base of the jaw and extend 2-2.5″ in height. The largest portion of the jaw bone is 18″ in length. Weisenfluh estimated the entire length of the jaw would have 30″. Weisenfluh also noted that this species had a permanent set of teeth unlike modern sharks who continually shed teeth throughout their lifetimes.

The story of a set of Megalodon jaws being up for auction in Dallas hit the news a couple of weeks ago. Recently, the AP released a video about the sale of the jaws, which contain 182 fossilized Megalodon teeth, 4 of which measure over 7 inches in length. The jaws “bones” themselves are actually fiberglass replicas.

The replica jaw was designed by Vito Bertucci a professional jeweler. An ABC News report about the auction notes that some scientists have disputed the accuracy of the jaw size and tooth placement. The jaw size is over-exaggerated due to larger front teeth being overly-repeated coupled with an unnatural slow decline in the progression from large to small teeth, according to shark fossil expert Kenshu Shimada. Despite conflicting opinions about the jaw size, the collection of teeth were still regarded as “beautiful specimens” by one of the scientists interviewed.

The shark jaws are set to go up for auction in June and are currently on display at Museum of Nature & Science in Dallas until they are sold. They are expected to sell for $700,000.

I think I can safely say that this is the first “commercial” I’ve ever seen for fossilized Megalodon teeth. Teeth of Megalodon (Dente de Megalodon) looks to be an online store dedicated specifically to the sale of Megalodon teeth found off of Belep, New Caledonia. While the site does seem to have a fairly wide selection of the fossilized teeth, the condition of most of them appears to be more on the “worse for the wear” side of things.

According to the National Geographic article, "Sea Monster" Bones Reveal Ancient Shark Feeding Frenzy, recent analysis of the fossilized bones of a plesisaur indicated the presences of over 80 sharks teeth embedded in the bones. The teeth were identified as belonging to the extinct species Cretalamna appendiculata, which was believed to have reached 3m in length. The plesiosaur was considerably larger at approximately 7m in length.

Paleontologist, Kenshu Shimada, believes that the plesiosaur was likely dead on near death when the shark bites occurred, as he believes that the sharks would have been no match for a healthy plesiosaur. While all of the teeth found embedded in the bones are believed to have come from the same species, the varying size and shape of the teeth indicate that sharks of various ages were involved in the "attack". Shimada estimated that at least seven different sharks of varying ages attacked the plesiosaur. For more information, check out the entire articles at National Geographic.