Figure 1. Diagram of the lamprey branchial basket and trabecula. The figure above depicts a pictorial illustration of an adult lamprey’s branchial basket and trabecula. The anatomy of the lamprey branchial basket was important because it served as a reference image when observing the embryonic development of lampreys. Within the pictures are abbreviations that are important for understanding the anatomy and development of the sea lamprey: T – trabecula, PC – parachordal, PA3-9– pharyngeal arch cartilages 3-9, EP – epitrematic process, HP – hypotrematic process, HBB – hypobranchial bar, SC – subchordal, NT – notochord.