Like the above poster said. If you had the worms in a container and did not separate any of the worms to force them to turn into beetles and you got beetles anyway, you most likely started with mealworms or what they market as "Giant mealworms". Giant mealworms are usually given hormones to delay them from turning into pupaes which increases their size. I have also read that giant mealworms may have been grown with brewers yeast to increase their size.
Superworms will be much larger and thicker. They grow to 2 inches long. If you got beetles without separating superworms, that is pretty lucky. Superworm beetles lay about 500 eggs in a lifetime. Mealworms can lay up to 200 eggs at a time.
If you really want to know what you have, maybe you can take a couple of worms and put them in a fridge area about 42-55 degrees. If they die they are supers, if they survive then they are mealies. Mealworms can be refrigerated but superworms cannot.
Timberline has some info on their site (they sell all three).
http://www.timberlinefisheries.com/care-instructions/
I keep about 1000 full sized mealworms per small shoebox sized plastic container.