Could an animal have both internal and external skeleton?

No, an animal cannot have both an internal and external skeleton simultaneously. Animals are generally classified into two major groups based on their skeletal structures: invertebrates and vertebrates. Invertebrates lack an internal skeleton and instead rely on an external skeleton or hydrostatic pressure for support and protection. Vertebrates, on the other hand, possess an internal skeleton made of bones that provides structural support and protection for their organs.

It is important to note that some animals may have exoskeletons (external skeletons) that cover and protect their internal organs, but these exoskeletons do not function as an internal skeleton. The internal skeleton of vertebrates is composed of bones, cartilage, and other connective tissues that provide structural support and protection to the body's internal organs.