Fossil Stingray Denticle
Fossil Stingray Denticle
Stingrays are an ancient and beautiful ray fish which have glided through the oceans for millions of years. Belonging to the superorder Batoidea, their ancestors were contemporary with dinosaurs, first appearing 145,000,000 years ago.
This specimen is a fossil denticle from a stingray. These denticles are specialized dermal scales, which provided armor and reduced water friction on the ancient animals. Since their skeletons are made of cartilage, like sharks, these denticles are one of the best ways we have to track the evolution of these majestic sea creatures. These particular denticles come from the Bone Valley formation in Florida and are estimated at 15 million years old.
📸 A selection of stingray denticles
15,000,000 Year Old Stingray Fossils
Stingrays are a graceful and ancient ocean predator. Using their flat and wide body shape, they can glide through the water at high speeds almost as if they were flying. Specialized electroreceptor organs allow these rays to detect electrical charges from prey and a razor sharp barb can deal the final blow once they get close.
We think of stingrays as a modern creature, but they have really been in the fossil record for millions of years. Early ancestors of the batoid superorder first swam with the dinosaurs over 145 million years ago. Closely related to sharks, their cartilage skeletons have difficulty fossilizing, but the enamel scales which armor their bodies make the perfect candidate for preservation.
These scales, called denticles, are structurally similar to teeth and layered in sharp rows not unlike a suit of chainmail. Each denticle is completely unique, with its own shape, size, texture and color. We've selected a few different specimens here to show the range available, but each will be its own fossil masterpiece.
📸 A close image of a single enamel scale
This fossil is a stingray denticle, a rare example of preserved material from a cartilaginous fish. These beautiful specimens show high levels of texture and detail that has been cast in stone over millions of years.
These denticles were recovered on private land from the Bone Valley formation in Florida. This fossil deposit is a rich site for Miocene sea fossils, as it was completely covered in ocean 15 million years ago.
Fossils range from around 0.5" to 1" in size. Each stingray denticle fossil comes in a classic, glass-topped riker display case that measures 4"x3"x 1". A small informational card that serves as certificate of authenticy is also included.
MORE ABOUT STINGRAYS
ESTIMATED AGE: 15,000,000 YEARS
📸 An artist's depicition of Prehistoric Stingrays
Elegant Sea Predators
Stingrays are incredibly advanced predators, which have swum through Earth oceans for over 60 million years. Closely related to sharks, they have a skeleton made up of flexible cartilage rather than hard bone. Unlike their cousins, however, stingrays are bottom feeders, prowling the ocean floor for crustaceans and shell life. They make use of electroreceptors, specifically evolved organs that allow rays to detect electrical charges given off by prey, providing a sixth sense that aids in hunting.
Stingrays don’t limit their prey to easy targets- their razor sharp, sometimes poisonous barb allows them to take down larger animals if provoked. This is not a fish you want to mess with.
Despite their abundance in the fossil record, the evolution of batoids (the scientific name for the ray fish superorder) is somewhat mysterious relative to their bony fish cousins. Many species have been identified, but their exact evolutionary path still has not been defined.
We do know that the first cartilaginous fish appeared during the Triassic period, over 200 million years ago, with batoids becoming defined by about 145 million years ago. From there, they spread throughout the oceans as a swift and efficient seafloor predator.
This fossil is one of a stingray’s denticles—the sharp scales that protect the fish from predators. They are anatomically similar to the animal’s teeth, made up of tough enamel, like a suit of armor to protect the stingray. Depending on the species, these scales can manifest as either a smooth continuous surface or grow into thorny spines to better protect the ray. But placoid scales (as they are also called) aren’t simply for protection from other predators. They can also aid in the animal’s locomotion, reducing drag from the water and allowing the stingray to glide easily, ready to sntach up some prey.
📸 The geographic location of Bone Valley, the source of these Stingray fossils
Formation of Bone Valley
This stingray fossil comes from the Bone Valley formation in Florida, a rich deposit of phosphate rock in the Sunshine State. Phosphate forms in part from decomposed material that has settled on the ocean floor. This means that Florida is the perfect place to look for phosphate because of its ancient geological history.
Millions of years ago, when the peninsula was underwater, Florida was a rich marine environment populated with many sea creatures. When these animals died, they would break down to their elemental components, leaving a massive deposit of phosphate and an abundant source of fossils still preserved today.
Aschliman, Neil C, et al. “Body Plan Convergence in the Evolution of Skates and Rays (Chondrichthyes: Batoidea).” Mol Phylogenet Evol, vol. 63, no. 1, 2012, pp. 28–42., https://doi.org/10.1016/j.ympev.2011.12.012.
“Phosphate and How Florida Was Formed.” Florida Industrial and Phosphate Research Institute, 9 Nov. 2021, https://fipr.floridapoly.edu/about-us/phosphate-primer/phosphate-and-how-florida-was-formed.php.
Santhanam, Ramasamy. Biology and Ecology of Venomous Stingrays: Biology and Ecology of Marine Life. CRC Press, 2018.
“Stingrays.” National Geographic, https://www.nationalgeographic.com/animals/fish/facts/stingrays.
Dodd, C. Kenneth, and Gary S. Morgan. “Fossil Sea Turtles from the Early Pliocene Bone Valley Formation, Central Florida.”Journal of Herpetology, vol. 26, no. 1, 1992, pp. 1–8.