Question

what does ossified endoskeleton mean?

Answer 1

endoskeleton which is made up of bones..and bony tissue..and composed of calcium phosphate..is ossified endoskeleton
ossi means made of bone
eg class osteichtheis(bony fishes)

Answer 2

An endoskeleton made of bones is known as an ossified endoskeleton.  

Most organisms like bony fishes, mammals, birds and reptiles have an endoskeleton made purely out of bones and cartilage. Bones are primarily made up calcium and phosphates and carry out the function of providing the body with a suitable frame work.  

However, certain organisms (echinoderms) show the presence of an endoskeleton made up of muscles, which cannot be termed as an ossified endoskeleton.