Calcite crystals – (KAL-sight) While calcite is one of the most common minerals in Florida, it’s rarely found in crystal form. Here, calcite in groundwater filled the empty spaces in and around fossilized clams, sea snails, and coral and crystallized, similar to how geodes form.

Dermal denticle – (DURR-muhl DEN-tickle) Also known as placoid scales, denticles are essentially modified teeth (not actual scales) that cover the skin of sharks, rays, and skates. They not only act as armor, affording protection from predators and parasites alike, but also increase the animal’s hydrodynamics by reducing drag and turbulence as it swims.

Dugong – (DOO-gong) A close relative of the manatee, it once roamed Florida waters in huge numbers but is now found exclusively in the eastern hemisphere – the east coast of Africa, western India, southeast Asia, and northern Australia. The most striking physical difference between the two is their tails. Whereas manatees have fan-like tails, those of dugongs are “fluked,” or v-shaped, like a dolphin’s. Dugongs are also exclusively marine (meaning they never leave saltwater), whereas manatees are both fresh and saltwater tolerant.

Glyptodont – (GLIPT-oh-dont) A giant, extinct armadillo relative that grew to the size of a VW Beetle: 5’ tall, 11’ long, and over 4,000 lbs. Its head, shell (or carapace), and tail were heavily armored by over a thousand individual scutes that were up to an inch thick, with an appearance somewhat resembling the unrelated and much older Ankylosaurid dinosaurs in a case of what paleontologists call convergent evolution, in which ecological pressures lead two or more independent species to evolve similar traits, features, or characteristics.

Megalodon – (MEGA-luh-don) The largest shark to ever live, it grew to lengths of over 60′ with teeth up to 7.5″ long. These enormous teeth, coupled with the strongest bite force in animal history (40,000 psi), allowed it to feed on large marine mammals like dolphins, dugongs, seals, walruses, and even whales in addition to sea turtles, large fish, and other sharks.

Mouth plates – Flattened plates inside the mouths of certain fish or rays that are used to crush their armored prey, such as crabs, clams, sea snails, shrimp, urchins, etc.

Mya – Abbreviation for “million years ago.”

Osteoderm – (AHS-tee-oh-derm) Latin for bone (osteo-) and skin (derm-), osteoderms are just that: bony deposits in the skin. In alligators and crocodiles, they serve three main functions: as armor; as a thermoregulatory apparatus (that is, they can either transfer warmth from the sun directly to the blood or dissipate heat if the animal becomes too warm); and to prevent acidosis, a condition in which acidic carbon dioxide builds up in the blood of a submerged, breath-holding animal, by releasing alkaline calcium and magnesium ions into the bloodstream.

Scute – (skyoot) Though often used interchangeably with the term osteoderm, scutes are technically the keratinous (the same material your hair and fingernails are made from) sheaths that lie on top of the osteoderm. Neural (NURR-uhl) scutes, or elements, are the scutes that run down the center of a turtle’s back and which fuse to the spine.

Steinkern – (SHTINE-kern) German for stone (stein) and kernel (kern), steinkerns are the internal molds, or stone casings, of bivalves (hinge-shelled mollusks like clams or oysters) and gastropods (spiral-shelled mollusks like snails or whelks).

Vertebrae (pl); vertebra (sg) – (VERT-uh-bray (pl); VERT-uh-bruh (sg) An animal’s spine or backbone(s). While taking on many different shapes and sizes depending on the animal and location in the spinal column, their function remains the same: to protect the spinal cord while providing flexibility.