Article: An extinct 'swan-goose' from the Pleistocene of Malta

Qualitative and quantitative studies on extinct Cygnus equitum/Anser equitum from the Ipswichian (Eemian) Interglacial of Malta (c. 125000 B.P.) show it was a broad-bodied, dwarf swan with some goose-like features. It was closer to Whooper and Bewick's C. cygnus than Mute Swans C. olor though the relative shortness of the chief hand bones resembles the latter. Feathered wing span was c. 1.5 m. The wings were probably more 'elliptical' than in other swans; 'stouter' carpometacarpus and ulna(?) suggest higher camber and relatively shorter hand bones suggest lower aspect ratio (length:width) than in Whooper Swans. There is no evidence to support assertions that it was flightless. The wings were fully feathered, it was light enough (c. 3.5-4.0 kg) to fly and the flight apparatus was not reduced. The femur was comparatively 'stout'. Abundant on the island, C. equitum may have swum on fresh and brackish water, walked well and, unlike other swans, have habitually taken off and alighted on land. It probably ate highly calorific plant food in enclosed, rather terrestrial habitats. Morphological differentiation facilitated coexistence with Whooper Swan and the giant, flightless, extinct swan C. falconeri. The two extinct, more advanced swans probably arose from the same fully flighted stock as Whooper Swans.