query: How big can a thresher get?
passage: Thresher shark
Named for their exceptionally long, thresher-like heterocercal tail or caudal fins (which can be as long as the total body length), thresher sharks are active predators; the tail is used as a weapon to stun prey. The thresher shark has a short head and a cone-shaped nose. The mouth is generally small, and the teeth range in size from small to large.[6] By far the largest of the three species is the common thresher, Alopias vulpinus, which may reach a length of 6.1 metres (20ft) and a weight of over 500 kilograms (1,100lb). The bigeye thresher, Alopias superciliosus, is next in size, reaching a length of 4.9m (16ft); at just 3m (10ft), the pelagic thresher, Alopias pelagicus, is the smallest.
passage: Withers
The withers in horses are formed by the dorsal spinal processes of roughly the 3rd through 11th thoracic vertebrae, which are unusually long in this area. Most horses have 18 thoracic vertebrae. The processes at the withers can be more than long.
Since they do not move relative to the ground as the horse's head does, the withers are used as the measuring point for the height of a horse. Horses are commonly measured in hands – one hand is . Horse heights are extremely variable, from small pony breeds to large draft breeds. The height at the withers of an average thoroughbred is , and ponies are up to .