Please help me add information about bosses and boss summoning here!

I've seen a lot of comments about "where is the altar" and how do I get the artifact. Unfortunatly I do not have a lot of answers. All I've found so far is something that looks like an altar in a cave (but seems not to work). And an altar in the Redwood biome - but you need an artifact for this and I do not know (yet) where to get this. So I thought it might be good to start a discussion about this and gather information in one place.

If you have any information (where the alters are, where to get artifacts, details on the boss, ...) please add it here. Thanks

Jungle terminal (Altar in Valley of Gods)
- Easy
- Coords 12.35-26.98
- Requires lvl 30
- Requires 2x Rock Drake Feathers
- summoned enemy gives Artifact of the hunter

Altar in the Redwood Biome:
- Coords 83.1 , 31,1
- Requires level 30
- Requires 2x Allosaurus brain, 1x artifact of the hunter

Corruption Terminal in Drei Zinnen Biome
- Coords 81.3 79.9
- RequiresAlpha raptor claw 2x t-rex arm
- Requires artifact of the pack
- Summoned Megapithecus in Alpha version! 540k health!

Plateau Terminal
- 17.8 83.4
- Requires 1 Wood