Which of the following statements is/are incorrect? Intramembranous and endochondral ossification both involve replacement of preexisting connective tissue with bone. Intramembranous ossification is the method by which flat bones of the skull, some facial bones, the mandible, and part of the clavicle are formed. Endochondral ossification is the method by which most of the bones of the body are formed. Endochondral ossification begins with development of an ossification center.