Breweries are always trying to do something original or unique to distinguish themselves from the competition. Whether it’s using a particular hop, aging in oak barrels, or adding fruit, breweries are always trying to do something different. Most beer goes through a filtration process, but at Kangaroo Island Brewery in Australia, they’re doing something you couldn’t imagine: filtering beer through dinosaur fossils. Well, kind of.

The beer is filtered through 500 million-year-old rock shale from Kangaroo Island. The island is prime dinosaur-bone finding territory, with paleontologists finding everything from marine life to a mysterious fossilized eye. Brewery owner Mike Holden told the Australian press his thought process behind the brewery’s paleontological experiment: “We just thought for this one, why not let millions of years of shale rock speak for itself and see what comes through.” And to add a bit of a pun to this unique filtration process, the beer is aptly named Shale Ale.

Holden takes an artisanal approach to all aspects of the beer he brews. He and his wife grow their own hops, grain, and even built their own brewhouse. But the filtering process ties the knot.

Diatomaceous earth, such as shale, is a pretty normal filter. Anchor Brewing uses diatomaceous earth to filter its beer, and the medium is used at plenty of other breweries. Other filters include isinglass, or fish bladders, which is common for cask ales and European beers.

Time to drink like it’s 500 million years ago.