The majority of fossilized sharks are found in a rock layer made of skeletal and shell parts of crinoids, blastoids, corals, gastropods, and brachiopods. The park says that To date, more than 70 ...

They belong to the Echinoidea, one of the five classes of the phylum Echinodermata, the others being holothurians, crinoids, starfish and brittlestars. Like all echinoderms, echinoids have a skeleton ...

Scientists have found ancient nail tooth shark fossils deep inside Mammoth Cave in Kentucky, revealing new information about a mysterious group of extinct predators.