Morphological and Experimental Studies on the Development of the Posterior Wall of the Avian Foramen Magnum

Abstract

In embryos of Gallus, Anas and Sphentscus the posterior wall of the foramen magnum (tectum synoticum) is formed by the fusion of the two independently developing supra-occipital cartilages. Fusion of the supraoccipital cartilage with the ear capsule precedes that between the supraoccipital cartilage and the occipital process. The supraoccipital cartilage intervenes between the occipital process and the ear capsule before fusion of these elements occurs. In Gallus the tectum synoticum is secondarily fused to the supracapsular cartilage.