Fig. 1

Masson stained slides showing the dense fibrous connections between the IAR and the dura mater in Xenopus laevis. The dense fibrous bundles from the IAR connected with the DAOM tightly or passed through the DAOM and then fused with the spinal dura mater (arrowhead) in sagittal (A, A’), transverse (B, B’) and coronal (C, C’). The DAOM fused with the spinal dura mater tightly in all the slices.
LGD: the longissimus dorsi muscle; IAR: the interarcuales muscle; EO: exoccipital; V1: the first vertebra; SC: spinal cord; DAOM: the dorsal atlanto-occipital membrane; arrowhead: the dura mater; arrow: the MDB connections.