part of part of forelimb tubercle pectoral flipper tubercle UBERON:0013527 A bump or swelling adorining the head and leading edge of a pectoral flipper, associated with the multiple joints and terminal phalanges as found in the multiple phalanges of the humpback whale. In a humpback the number of tubercles ranges from 9 to 11, with the first at the joint between the radius and metacarpal of digit II (with digit I absent)