The furcula is the name of some fork-like structures in animal anatomy:

Birds

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In birds, the furcula is a forked bone which is formed by the fusion of the two clavicles in most modern birds and some theropod dinosaur species, first appearing in the archosaur Longisquama ^*. Its modern function is the strengthening of the thoracic skeleton to withstand the rigors of flight.

It is also commonly referred to as a wishbone because of the tradition that when two people hold the two sides of the bone and pull it apart, the one who gets the larger part will have a wish granted.

Arthropods

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In springtails, the furcula is an abdominal, tail-like appendage that is present in most species and is folded beneath the body, to be used for jumping when the animal is threatened.

Animal anatomy | Birds