OK, this is a guess but it looks a lot like a Manicinia areolata to me. Your's (if that's what it is) looks like it's starving!! You should feed it cyclop-eeze ir even a silverside (if you can keep the shrimp and hermits away) and it will inflate quite a bit. Here's a pic of mine and the LFS didn't feed it anything meaty and when I first got it, it was flat like yours and hard to the touch. It's only a thin layer of tissue on top of the skeleton. Took only a few good feedings to "puff up". HTH