Great white sharks, the chainsaws of the sea, became a cultural phenomenon ever since the film Jaws released in 1975. Though encounters with humans are statistically rare, the shark’s reputation isn’t entirely unearned. After all, your species doesn’t stick around for millions of years without being the best there is at what it does (eat things, that’s what it does). Well, should you ever find yourself in the water coming face to face with the largest great white shark you could possibly imagine, consider this: That shark only got so big because it might be older than your grandpa, according to the National Oceanic and Atmospheric Association (NOAA).

Sharks are typically aged by counting alternating opaque and translucent band pairs deposited in sequence in their vertebrae. It is unclear whether these band pairs are deposited annually, which is to say this is a terrible way for gauging the age of a shark. The goal of this NOAA study was to see if they could validate more accurate results using radiocarbon dating on the band pairs.

“Ageing sharks has traditionally relied on counting growth band pairs, like tree rings, in vertebrae with the assumption that band pairs are deposited annually and are related to age,” said Lisa Natanson, a fisheries biologist in the Apex Predators Program at NOAA’s Northeast Fisheries Science Center (NEFSC) and a co-author of the study. “In many cases, this is true for part or all of a species’ life, but at some point growth rates and age are not necessarily in sync. Growth rates slow as sharks’ age. Deposition rates in vertebrae can change once the sharks reach sexual maturity, resulting in band pairs that are so thin they are unreadable. Age is therefore frequently underestimated. ”

Sharks are one of the relative few species on Earth to actually live long enough to make radiocarbon dating a viable means of determining age. Just how long do they live?

Testing four male and four female sharks caught between 1967 and 2010, the age findings were across the board: Ages for the three of the males males were 9, 14, and 44, while three of the females sampled had estimated ages of 6, 21, and 32. The oldest female white shark sampled was 40, and for the oldest male was a whopping 73 years old.

Predictably, scientists were shocked to see specimens that old. Previous attempts at dating sharks via band pair suggested that no specimen ever found lived to be older than 23. This is now believed to be a slight underestimation.

Sharks, surprisingly, aren’t entirely unlike people: They take a long time to reach maturity, raise relatively few young, will eat more or less whatever is put in front of them and can live a long time. Those same similarities may also be putting great white sharks more at risk than previously thought.

With lifespan estimates of 70 years and more, white sharks may be among the longest-lived fishes. Sharks that mature late, have long life spans and produce small litters have the lowest population growth rates and the longest generation times. Increased age at maturity would make white sharks more sensitive to fishing pressure than previously thought, given the longer time needed to rebuild white shark populations.

The great white shark is the world’s largest predatory fish, and is currently at “vulnerable” status as a species with the World Wildlife Fund.

Do you think your chances of survival would be any better if you knew the shark bearing down on you was a septuagenarian? Let us know in the comments.