In Ark ascended, the artifact is near the beginning of the cave, just before the part where there is land, so i strongly advise you to not bring a Baryonyx if you want the artifact only, bring your Basilo or Mosa to tank all the medusas and eletric eels. The artifact can be tricky to find since it is underwater and probably swarmed by creatures.

And in any hipotesis go there by yourself or with a weaker tame than the two i mentioned.