Scientists still don’t know why the giant Megalodon shark — which measured up to 60 feet long — went instinct many eons ago, but they now have a better idea of when it happened, according to the Christian Science Monitor.

A new study that examines dozens of Megalodon fossils now suggests that the extinction of the monster shark happened about 2.6 million years ago, putting it between the Pliocene and Pleistocene Epochs on the cusp of the increase in size of baleen whales.

Because of when the Megalodon became extinct, scientists believe that the giant shark ate whales and dolphins, and once it died out, whales were able to grow to much larger levels.

The Megalodon’s fossil record is incomplete, making it difficult for scientists to determine exactly when its extinction happened, but have found ways of examining its most recent fossils to get a better approximation. Most Megalodon fossils date between 11.6 million and 15.9 million years old — the Miocene Epoch — and between 5.3 million and 2.6 million years old — the Pliocene Epoch, so researchers focused on the 42 newest fossils.

Researchers used a technique called the Optimal Linear Estimation (OLE) by entering each of the fossils into a database with an upper and lower estimate for age. After 10,000 simulations, a date was selected for each fossil. After those 10,000 estimates, scientists can take a look at the distribution of them through time, pinpointing where most of the estimates cluster. For the Megalodon, it was at 2.6 million years.

Six of the simulations placed the shark beyond the present day, suggesting it could still be alive, but that is misleading, the team noted: 99.9 percent of simulations suggest the species is extinct, those making its present day survival unlikely. The team noted that the six outliers have to do with uncertainty in fossil record dates, but that doesn’t suggest Megalodon is stil patrolling the waters today somewhere.