Gem and Ornamental

mything hm fish and birds to the largest whales, k s catch thislarge prey by working together and hunting in groups. Although theymay taw their prey before killing it, orcas kill to feed, rather than forpleasure.An orca has -50 teeth: 1&13 on each side of the top and thebottom jaws. The teeth interlock neatly when the jaw is closed. Orcateeth are slightly smaller and narrower than those of the sperm whaleand tend to curve slightly inwards and backwards to facilitate feedingoff larger prey.The teeth of both species are solid for most of their length and areenamel tipped. The rest of the tooth is covered with a layer of cementum.In moss-section they appear round or slightly oval, with a mansirionring evident between the cementum and the dentine. The dentinedisplays he, concentric rings, with a dark spot in the centre (Fig. 3.4).In longinrdinal section the cementum is still clearly visible on the outerFigure 3.5 Tho tupihh hm Greenland. Mid-twentiethSpermwhale ivorg (atanding) and mmhd ivory.century.