Helix Fossil

The Dome Fossil (Japanese: こうらのカセキ Carapace Fossil) and Helix Fossil (Japanese: かいのカセキ Shellfish Fossil) are fossils which can be regenerated into Kabuto and Omanyte, respectively.

In the games

In the Generation I and III games, the Dome and Helix Fossils are key items found in Mt. Moon after defeating a Super Nerd. While both are present, players are allowed to choose only one, as the other one will be taken by the Super Nerd. If brought to the Pokémon Lab on Cinnabar Island, the Dome and Helix Fossils can be regenerated into Kabuto and Omanyte, respectively. The Pokémon extracted from the Super Nerd's fossil is seen in the zoo just outside the Safari Zone.

In Diamond, Pearl, and Platinum, they are no longer key items, being demoted to simply items. They can be found by mining in the Underground after obtaining the National Pokédex. Helix Fossils are more common in Diamond while Dome Fossils are more common in Pearl. If brought to the Oreburgh Mining Museum, the Dome and Helix Fossils can be regenerated into Kabuto and Omanyte, respectively.

In HeartGold and SoulSilver, the Dome and Helix Fossils can be found randomly by smashing rocks at the Ruins of Alph. The Dome Fossil is exclusive to SoulSilver while the Helix Fossil is exclusive to HeartGold. If brought to the Pewter Museum of Science, the Dome and Helix Fossils can be regenerated into Kabuto and Omanyte, respectively.

In Black and White, a Worker in the Ice Rock room of Twist Mountain hands out a random fossil from previous generations, including the Dome and Helix Fossils, once per day. If brought to the Nacrene Museum, the Dome and Helix Fossils can be regenerated into Kabuto and Omanyte, respectively.

In the anime

A Dome Fossil in the anime

Dome Fossils in the anime

In the anime, Dome Fossils are seen in Shell Shock. They make up the structure of an island, and are revived into Kabuto in red moonlight, causing the whole island to collapse and sink.

In A Night in the Nacrene City Museum!, a Dome Fossil was first seen chasing Hawes, as he claimed it to be doing, but was later seen safely placed in a display case. Hawes later explained what it was to Ash and his friends. It was later revealed that the Yamask in the Nacrene City Museum was using its move Psychic to make the Dome Fossil float and chase after Hawes after he put its mask in a display case, thinking that it was a replica Yamask mask given to him as a gift from the company that made a Cofagrigus replica after purchasing it from them for the museum.

In the TCG

Both fossils appear on the artwork for the Mysterious Fossil card. However, the artwork depicts the Dome Fossil as the fossil of a Kabutops, Kabuto's evolution, rather than of a Kabuto. The two fossils were later split off into their own individual cards.

Name	Type	Set	Set no.
Mysterious Fossil	T	Fossil	62/62
		Legendary Collection	109/110
		EX Sandstorm	91/100
		EX Legend Maker	79/92
		EX Holon Phantoms	92/100
		EX Power Keepers	85/108
Dome Fossil	T	Majestic Dawn	89/100
Dome Fossil	T	Platinum: Arceus	92/99
Helix Fossil	T	Majestic Dawn	91/100
Helix Fossil	T	Platinum: Arceus	93/99