The internet is filled with articles and Redditors pointing out the anachronisms of Netflix’s 1980s science fiction throwback series Stranger Things — from Barb’s Volkswagen car to the Demogorgon figurine. Now, scientists are joining the ranks of nitpicking nerdy fans.

Stranger Things season 2 spoilers ahead.

In Stranger Things’ second season, Dustin adopts a tadpole-like pet that loves nougat that is actually the baby version of a flesh-eating monster from The Upside Down. In episode 3, while trying to understand what exactly the pollywog is, Dustin pulls out a book and points to a species of frogs whose tadpoles develop outside the water: Indirana semipalmata. Problem is, the Indirana genus wasn’t named until two years after the show’s second season setting, as Christian Kammerer, a paleontology curator at the North Carolina Museum of Natural Sciences, pointed out in a tweet this weekend.

“This one, I think, may be the most nitpick-y and pedantic comment about anachronisms that has been made thus far,” Kammerer tells The Verge. “It probably helps that I spent a lot of time growing up in the 1980s reading field guides to reptiles and amphibians.”

Indirana is a South Asian genus of frog that is unique in that they have terrestrial tadpoles. Tadpoles usually live in water, but Kammerer says Indirana tadpoles develop on moist surfaces, like rocks and leaves, outside the water. While Indirana frogs have been known since the 19th century, Kammerer says the genus — or the ranking used to classify organisms with similar characteristics — wasn’t named until 1986, by Belgian herpetologist Raymond Laurent.

The pollywog in Stranger Things season 2 doesn’t like water, according to Dustin. And that’s why the brainy Hawkins kid points to Indirana semipalmata as a possible species identification. “The creators of the show did great work in getting it right,” Kammerer says. “A lot of shows just would not bother to look up that scientific information.” The nougat-eating pet in the series does look pretty similar to a tadpole, though it develops in the opposite order of most tadpoles — it sprouts front legs first, then back legs.

The one thing Kammerer actually does wish the show would do better? Its depiction of government scientists as “evil and conspiratorial.” “In an age when we’re trying to educate the public about things like vaccines and climate change, maybe it’s not the most helpful thing in the world,” he says.

Kammerer admits his tweet on the Indirana genus is not a serious complaint. “My comment that it was unforgivable is entirely sarcastic, but it did take me out of the fiction,” he says. As a scientist, he finds it nearly impossible to watch a movie without finding mistakes or inaccuracies, but that doesn’t necessarily ruin his experience.

“You’re able to appreciate things on their own merits,” he says. “I still enjoy Jurassic Park, even though that thing is chock-a-block full of errors about dinosaurs.”