The Apolith is an archetype of Level 3 EARTH monsters created by LHK. It is an archetype that focuses on quickly Synchro and Contact Fusion Summoning. They represent bionic versions of fossils, most commonly Dinosaur fossils.
The Apoliths are focused on Contact Fusion and Synchro Summoning. Thus, they need some monsters that can help you perform the Synchro part of the Deck. The Tuners, which are non-Dinosaur fossils, are most probably Rock-Type and Winged Beast-Type, and they are the combo creators of the Deck. They allow you to Synchro Summon quite fast at times, while they allow you to Synchro Summon with weird ways (e.g. Synchro Summoning using Synchro Materials from the hand, Synchro Summoning on your opponent's turn). The Dinosaur-Types, though, rely on two things. They are the non-Tuners used for the Synchro Summon portion of the Deck, while they serve as powerhouses for the Contact Fusion part of the Deck, with some of them having effects that enhance the Fusion or Synchro that was Summoned using this card. They help you Xyz Summon Rank 3 Xyz Monsters, if you desire some Xyz action in the Deck.
The Apolith monsters are named after a corruption of a fossil of a mythological beast or dinosaur.