"It would not surprise me at all if a T. rex individual scared a little Galagadon as it lowered its head to drink", said North Carolina State University paleontologist Terry "Bucky" Gates, lead author of the research published in the Journal of Paleontology.
Sharks have thrived for millions of years. This new species would have thrived along side Sue, in the same world, during the Mesozoic era. The prehistoric shark, which has been named Galagadon nordquistae, was found alongside "Sue" the Tyrannosaurus rex-the largest and most complete T. rex fossil ever found.
The tiny teeth - each measuring less than a millimetre across - were discovered in the sediment left behind when palaeontologists at the Field Museum in Chicago uncovered the bones of "Sue", now the most complete T. rex specimen ever described.
An ancient shark with teeth resembling spaceships from the 1980s video game Galaga has been discovered in the Hell Creek Formation. "Today, carpet sharks, which include bamboo sharks and wobbegongs, mostly live in the waters in southeast Asia and Australia, so it's surprising to find their fossils at the Sue locality", study co-author Eric Gorscak said in a statement.
"It was so tiny, you could miss it if you weren't looking really carefully", says Nordquist, a retired chemist who has been microsorting, or sifting through dirt to find tiny fossils, for the Field Museum for fifteen years. "Without a microscope you'd just throw them away".
The new species, named Galagadon nordquistae, is long gone. "This shark had teeth that were good for catching small fish or crushing snails and [crayfish]". "It would have eaten small invertebrates and probably spent a fair amount of time lying on the bottom of the riverbed".
"This shark lived at the same time as Sue the T. rex, it was part of the same world", said Dr. Pete Makovicky, curator of dinosaurs at the Field Museum.
"This wasn't some Sharknado event-these animals were making their way up rivers from the sea", Makovicky said in the release, referencing the popular SyFy made-for-TV movies which have become a cultural phenomenon.
According to the Field Museum, the study also reflects the importance of learning about fossils beyond big, flashy dinosaurs. "There is no way for us to understand what changed in the ecosystem during the time of the mass extinction at the end of the Cretaceous without knowing all the wonderful species that existed before".