Researchers have reported the discovery of fossilized teeth that belonged to a small prehistoric shark that lived 67 million years ago when dinosaurs still walked on Earth.
Galagadon
Scientists called the freshwater shark Galagadon nordquistae because of the odd shape of its teeth.
The prehistoric fish had triangle-shaped teeth that looked like the spaceships in the 1980s video game Galaga.
Galagadon was a small shark that measured 30 to 46 centimeters in length. It swam in the Cretaceous rivers of modern-day South Dakota, where it likely used its odd teeth to catch small fishes or crush snails and crawdads.
Galagadon is a relative of present-day carpet sharks, which include the bamboo sharks and wobbegongs that mostly swim in the waters in Southeast Asia and Australia.
Discovered Alongside Famous Dinosaur Specimen
The teeth were found in the same deposits where Sue, the most complete and best preserved Tyrannosaurus rex specimen, was found in 1990.
When the famous T-Rex was unearthed, the encasing rock called matrix was left around the bones to keep them safe, but Chicago's Field Museum, which now houses Sue, saved the matrix for future study.
Nearly three decades later, the matrix yielded the tiny teeth of Galagadon.
Tiny Teeth
The teeth could be easily missed because of their size. Each measuring less than a millimeter across, the teeth are just the size of a sand grain.
"It amazes me that we can find microscopic shark teeth sitting right beside the bones of the largest predators of all time," said North Carolina Museum of Natural Sciences research affiliate Terry Gates, lead author of a study that described the new species. "Without a microscope you'd just throw them away."
Galagadon's Body Not Found
Unlike Sue, the body of the Galagadon was not preserved.
Field Museum's curator of dinosaurs Peter Makovicky, who is also author of a study, explained that this is so because the skeletons of sharks are made of cartilage.
The discovery was reported in the Journal of Paleontology on Jan. 21.
