Otherwise the word callosity is generally reserved for describing the calluses found on the head of the three species of right whales.
Callosities are a characteristic feature of the Eubalaena genus of whales; because they are found on the head of the whale and appear white against the dark background of the whale's skin, they make it very easy to identify these species. The callosities themselves are grey; the white appearance is due to large colonies of whale lice around them. Callosities arise naturally and are present even in late-term whale fetuses, although the work of lice digging into the surface of the skin may make them more jagged and hard over time.
The evolutionary purpose of callosities is unknown. Male right whales have a higher density of callosities than females. Males have been observed scratching one another with their callosities, so they may play a role in sexual selection. This explanation is not entirely satisfactory, as it does not account for the appearance of callosities in females.
Callosities form a unique pattern on every right whale. This makes them an extremely useful tool for the purposes of photo-identification and conservation.
Clinical results of modified Mitchell's osteotomy for hallux valgus augmented with oblique lesser metatarsal osteotomy
Dec 01, 2005; ABSTRACT Purpose. To evaluate postoperative results of modified Mitchell's osteotomy and its combination with oblique metatarsal...