This is the 13137th most frequent Spanish word.
prehistóricas
"Prehistóricas" means "prehistoric," referring to the time before written history.
Here, 'prehistóricas' is used as an adjective to describe 'pinturas', indicating the paintings belonging to the prehistoric era.
Las pinturas prehistóricas en las cuevas son fascinantes.
The prehistoric paintings in the caves are fascinating.
In this sentence, 'prehistóricas' describes 'herramientas', specifying that the tools originate from prehistory.
Estudiamos las herramientas prehistóricas en el museo.
We study the prehistoric tools in the museum.
'Prehistóricos' modifies 'restos', indicating the remains are associated with the prehistoric period.