2+ hour, 7+ min ago (172+ words) Modern sharks trace their origins to the Age of Dinosaurs, with the oldest known lamniform fossils dated to about 135 million years ago. These early sharks started small, around 1 meter in length, but later produced larger species including the Megalodon, which may have reached lengths up to 17 meters, and the Great White shark, now reaching about 6 meters. Because sharks have cartilaginous skeletons, their fossils mainly consist of teeth. Fossil shark teeth are common in ancient seabed sediments and are found alongside remains of bony fish and marine reptiles. To estimate the shark's true size, a team including paleontologists and tomographic experts from Sweden, the U.S.A., South Africa, and Australia collaborated on the reconstruction. The study is published in Communications Biology, and fossil specimens from the Age of Dinosaurs are exhibited at the Swedish Museum of Natural History. Research Report: Early gigantic lamniform…...