Seabed Cavern is the 10th Dig Site to be "unlocked". However, it is only accessible through the storyline. Once the battle takes place and the Spinal Pillar is re-calcified, you are unable to return to this Dig Site.
In order to effectively acquire the fossils of the Vivosaurs that are found here, many of which are extremely rare, you must dig until you are prompted to prepare for battle. Once you get this message, decline and return to Robinson. Robinson will allow you to visit this dig site as often as you want until the battle is completed. Because of this, you can continue excavating Seabed Cavern until you get the desired fossils. If you obtain a full case and are still unsatisfied, leave the Bonehemoth and clean or revive any fossils needed before continuing the process.
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This article contains plot details about the story of a game.
The members of the Caliosteo Patrol Team gather in Joe's Suite to discuss the matter. Joe informs them that if the pillar is chipped at enough it will snap and topple over, causing the islands to sink beneath the waves. He says that tragedy is, however, avoidable; the pillar can be restored with an injection of pure calcium. He states that calcium can be found in the fossil of a prehistoric fish- Sardinisaurus. According to the western man, Sardinisaurus can be found in a Ribular dig site that was previously sealed- the Petrified Woods.
Armed with information and an upgraded sonar, the Hero hurries to the dig site and traverses it, eventually finding the requested Sardinisaurus fossil atop an ancient tree at the end of the wood. Fossil in hand, the player returns to Joe on Cranial Isle.
Joe takes the fossil from the Hero and extracts the needed calcium from it. He gives instructions to the player to take the calcium injector he has prepared and head to the Seafloor Cavern with it.
After a hurried discussion concerning methods of descending to the seafloor, Rupert, Pauleen, Todd, and the Hero race off to the Bonehemoth to ask Robinson for permission to use the colossal ice-gobbling beast to dive beneath the water. Robinson, knowing precisely how to force the whale to sink beneath the waves, tells the party that tickling the beast causes it to submerge.
Robinson tells the group that there are three entrances to the Seafloor Cavern- one beneath Cranial, another at Ribular, and a third below Ilium. He suggests that the party part and send one individual through each entrance. The four agree to his plan, and the man beckons Todd to him, requiring his assistance in tickling the whale. Todd and Robinson work their magic on the Bonehemoth, and it sinks beneath the waves.
Pauleen and Rupert exit the whale first, in sequence. At the final entrance, the Hero leaves the beast, calcium injector in hand. Todd decides to stay behind to keep the whale calm.
The player finds Cole, a commander of the BareBones Brigade, with two lackeys, working away at the Spinal Pillar with picks. The goons cease their chipping after spotting the Hero. Cole is stunned by the player's persistence but informs them that their days of meddling have come to an end. He engages in a Fossil Battle with the Hero and is promptly defeated.
In signature fashion, Cole runs away bawling and his two underlings come scurrying after him. The player wastes no time in approaching the pillar and injecting the vital calcium into it. Almost instantaneously the pillar heals and fills back out to its normal size.
PS: If you do not get all of the Vivosaurs there,here are there the alternate locations. Using the head mask or the respective color mask will make finding the special Vivosaurs easier to find:
- Although there are fossils beyond the battle prompt, you can never reach them. This misleads many into thinking that the "Dig Site" can be returned to. However, rest assured, it CANNOT be returned to, EVER.
- The Spinal Pillar, the sole purpose for the existence of Seabed Cavern, may be alive, considering it grew back with the aid of additional calcium.
- Although you can't come back to Seabed Cavern, you can find the fossils found here at other places, though they are rare and very hard to find.
- All of the Vivosaurs that are found in Seabed Cavern are extremely hard to find in their alternative dig sites. Getting them here is recommended.