alternative definition added over 14 years ago by Andy Deans
The dorsal Y-shaped suture of the cranium, including the median coronal suture of the vertex, and the divergent frontal sutures of the facial region.
Reference: Snodgrass, R. E. 1935. Principles of insect morphology. McGraw-Hill Book Co., Inc., New York & London 667 pp.
Cross reference:
None provided.