Scalps (1983)

A group of archaeology students go into the desert to do a dig and are warned not to dig in an Indian graveyard, so you know they're going to ignore that bit of advice.

On their way to the desert, an old Indian warns them to stay away from the Black Trees, which they promptly find and enter. Good god man! You're going to ignore two warnings?  Stupid archaeology students, you should know better.

One student is possessed by the spirit of Black Claw which leaves the others to be massacred by said spirit. Why don't kids ever listen?

This is a Fred Olen Ray movie, which tells you a lot of what you need to know. It's low budget and slow paced.  There are scenes where it switches from night to day to night again.

There is an anamatronic lion head on someone in the desert. Why?  No idea. There is also an Indian that has a monster face, but a normal body.  Eventually the movie degenerates into lots of running at night, which isn't the easiest to see.

Ridiculous dialogue:

• "There's evil in the ground!  It's alive with evil!"
• "Look!"  "It's blood..."  "... and it's coming from nowhere."