Previously, giant sharks had only been recovered from rock dating back 130 million years, during the age of the dinosaurs. The largest shark that ever lived, commonly called "Megalodon", is much younger, with an oldest occurrence at about 15 million years ago. This means the new fossils from Texas indicate giant sharks go much further back into the fossil record.
After the generous donation of these fossils and careful study with Dr. John Maisey of the American Museum of Natural History in New York, the team was able to estimate how big the entire sharks would have been by comparison with smaller and more complete fossils of closely related sharks. The results were very impressive.
The size range estimated for these two Texas 'supersharks' was between 18 and 26 feet in length (5.5 to 8 meters). The largest of these specimens was 25% bigger than today's largest predatory shark, the Great White. Although not nearly as large as Megalodon, which might have reached up to 67 feet in length (about 20 meters), the fossil sharks from Texas would have been by far the biggest sharks in the sea.