These are professionally prepared skeleton mounts. Each skeleton is cleaned and articulated in a natural posture on a wooden base with a removable clear acrylic cover.
This comparison mount consists of the skulls from a specimen of the five classes of vertebrates: Mammal (rabbit), Bird (pigeon), Reptile (tortoise), Amphibian (toad) and Fish.
The case is 13.75" long by 4.25" wide, and 2.25" high, including the cover. Overall, it weighs 1.24 lbs.