Caltiki the Undying Monster (1959)

 Caltiki the Undying Monster (1959) 

Archaeologists investigating some Mayan ruins come across a blob-like monster. They manage to destroy it with fire, but keep a sample. Meanwhile, a comet is due to pass close to the Earth - the same comet passed near the Earth at the time the Mayan civilization mysteriously collapsed. (IMDB James Barrett) V&D