The furcula (from the Latin "furca", meaning "fork") is found in the upper "chest" area of theropod dinosaurs and is formed by the fusion of the two clavicles (collar bones). It is also one of the reasons for the theory that birds evolved from dinosaurs: the furcula is commonly known as "the wishbone". In birds, its function is to strengthen this part of the skeleton for the rigours of flight. But its function in larger (flightless) theropods is uncertain.
Further reading
• Schultze H-P and Trueb L (1992) "Origins of the Higher Groups of Tetrapods: Controversy & Consensus".
• Paul GS (2002) "Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds".
• Currie PJ, et al. (2004) "Feathered Dragons: Studies on the Transition from Dinosaurs to Birds".
• Ward P (2006) "Out of Thin Air: Dinosaurs, Birds, and Earth's Ancient Atmosphere".
• Long J and Schouten P (2008) "Feathered Dinosaurs: The Origin of Birds".
• Pickrell J (2014) "Flying Dinosaurs: How Fearsome Reptiles Became Birds".
• Chatterjee S (2015) "The Rise of Birds: 225 Million Years of Evolution".
• Chiappe LM and Meng Q (2016) "Birds of stone: Chinese avian fossils from the age of dinosaurs".
