American researchers have unearthed two fossil brain-cases of massive extinct relatives of present-day sharks that were roaming in Texas some 300 million years ago. These huge sharks were resident to present day Texas at a time known as Carboniferous era, even before the dinosaurs made their appearance.

Much of the present-day Texas was flooded by a shallow sea in the Carboniferous era some 300 million years ago. The shark fossil includes two brain cases said to be the ancestors of present-day sharks.

Earlier remnants of these giant sharks were recovered from a rock dated back to 130 million years in the age of the dinosaurs. The largest shark that was ever recovered was Megalodon and was much younger and only 15 million years old.

The latest discovery of the remains of these creatures in Texas hints that these giant sharks belong to a much older era.

Researchers at the Dallas Paleontological Society and American Museum of Natural History are carefully evaluating the latest findings and comparing it with complete fossils of closely related sharks to estimate how big they were in comparison to these sharks.

Researchers have estimated the size of these super sharks in the region between 18 to 26 feet in length. The biggest of this specimen was 25% bigger the largest present day predatory shark, the Great White Shark.

However, the super shark is much smaller than the Megalodon, which is estimated to be 67 feet in length. Still it was the biggest sharks in the sea.

The study was published in the Journal of Vertebrate Paleontology.