somatopleure /sô″mətōplo͝or′/ [Gk, soma + pleura, side] , the lateral and ventral tissue layer that forms the body wall of the early developing embryo. Consisting of an outer layer of ectoderm lined with somatic mesoderm, it continues as the amnion and chorion external to the embryo. Compare splanchnopleure. −somatopleural, adj.