With each and every new generation of Pokémon games, there is always a new set of fossil Pokémon, and that's certainly no different when it comes to Sword and Shield. Ever since Kabuto and Omanyte popped up in the original Pokémon Red and Blue, players have been able to uncover ancient fossils in the Pokémon world. Just like in the original games, you'll need to follow a few specific steps if you want to turn those fossils into Pokémon in Sword & Shield.
The fossil Pokémon that you'll be able to find in Sword and Shield consist of Dracovish, a water-dragon-type Pokémon, Dracozolt, an electric-dragon-type Pokémon, Arctovish, a water-ice-type Pokémon, and Arctozolt, and electric-ice-type Pokémon. All four of these Pokémon only have one stage, and do not evolve into anything else.
Just like in previous games, you'll need to obtain fossil items and then turn them into the Pokémon themselves, but it's a bit different this time around. Instead of just taking a fossil to a professor in some research facility and get it turned into a Pokémon, you'll actually need to combine two different types of fossils this time. The Pokémon that you get will depend on which two fossils you decide to combine.
In Pokémon Sword, you'll be able to obtain the Fossilized Bird, and the Fossilized Dino. In Pokémon Shield, you'll be able to obtain the Fossilized Drake and the Fossilized Fish. If you combine the Drake and the Fish, you'll get Dracovish. If you combine the Drake and the Dino, you'll get Dracozolt. If you combine the bird and the fish, you'll get Arctovish, and if you combine the Bird and the Dino, you'll get Arctozolt. This means that in order to obtain all four Pokémon, you'll need to either buy both games or trade with someone who has the other version.
You can find these fossils by digging in the Wild Area when you talk to the Digging Brothers. You'll need to spend 500 Watts per dig, and there's no guarantee as to what items you'll receive, so it may take a few tries. Once you've found the fossils you want, you can take them to the professor on Route 6, who will then transform them into Pokémon.