My review was written in January 1987 after watching the film on Lightning video cassette.
"Massacre in Dinosaur Valley" is a poor Italian exploitation film, made worse by an intentionally misleading title: there are no dinosaurs or fantasy elements in this potboiler. Pic was lensed in Brazil in 1985 with "Stranded in the Valley of Dinosaurs" as its working title.
Format is in the corny vein of "Five Came Back": a bunch of folks are caught in the jungle and swamp when their light plane crashes en route to Manaos. Among the passengers are an archaeologist (Michael Sopkiw), a scientist who's killed in the crash, his pretty daughter (Susane Carvall, usually credited as Suzanne Carvalho) plus several other beauties. They're attacked by indians, fall prey to leeches and quicksand, plus the other tired gimmicks of the genre.
Sopkiw finally frees two girls from the clutches of the indians and an hour into the film finds fossilized dinosaur footprints. Just when the film might be getting interesting, the three survivors are captured by a creep using slave labor for his mining operations. The rest of the picture is devoted to the boring subplot of Sopkiw engineering another escape with Carvalho.
This sexploitationer mixes pratfall comedy, disrobing women and the usual gore carelessly.