Seeking name of very old (1940-1960) science fiction movie

I remember watching an old b&w scifi movie and have been trying to find the name. It has two scenes that I remember. One is folks driving on another planet in a jeep like vehicle in a sandstorm and a creature runs up (you can hear the footsteps) and snatcheds someone out of the jeep. It does this until only the driver is left. The second scene is when they kill the creature on the spaceship by letting it suffocate and it is half in/half out of a hatch in the floor like a manhole cover.  At any rate, hoping someone out there can remember the name for me. Thanks.