Fig. 1. Sei whale rostrum and baleen: (A) ventral view of rostrum showing finer baleen plates, including shorter plates at the anterior. (B) side view of baleen, demonstrating the finer structure of the baleen plates. (C) baleen plates cut across at the gumline (30cm scale) showing the limited curvature of the plates and finer baleen mesh. (D) profile of right mandible, showing the curvature as well as the pronounced depression near the tip. (E) frontal view of cross-section through the rostrum and baleen rack, showing the greater vertical angle of the baleen relative to the rostrum, as well as the relatively smaller vomer and greater volume at the roof of the mouth, relative to a fin whale.