Although, as we have seen, the 1950's was the decade of the B-Movie, some were good (Rodan, Godzilla) and some were not (Attack of the Crab Monsters, The Giant Claw). In between there are films such as 1957's The Land Unknown. From the IMDb:
This movie oozes potential. A reasonable script, decent actors, good pacing, spectacular sets, and the grandeur of CinemaScope. Then you see the dinosaurs.... oh lord, do you ever. One can easily see where their budget ran dry. The movie employs the two worst methods of portraying dinosaurs, and doesn't even do it well. However, the compositing is nearly seamless, so if it were possible, one could become convinced that the producers managed to find a 20 foot tall man to wear a full size Tyrannosaurus costume.
Aside from the special effects, the movie is quite good, nearly rising above B-movie status. The actors all seem for the most part, naturalistic. They all seem to find the line between flat and hammy. The movie never wastes much time on non-essential plot elements, and the running time works out quite well.
Seldom in a sci-fi film are the men-in-rubber-suits so obvious. The tyrannosaur seen above looks bad enough to begin with, but when you see it move, as found in the 1957 trailer embedded below, hilarity ensues. Watch this with your Jurassic-Park-Kids and gauge their reaction. Then tell them that people used to pay to see films like this.
The full movie is available on YouTube and is also embedded below. I have fond memories of watching it on TV Saturday afternoons in the 60's, but, as is also the case with drive-in theaters, I really doubt that today's kids will ever have the pleasure.