Caspians can range up to 782 g (1.724 lb), a 1.4 m (4.6 ft) wingspan and 0.6 m (2.0 ft) in length.[35][36] The largest extant alcid is the sub-Arctic thick-billed murre (Uria lomvia), which can range up to 1.48 kg (3.3 lb), a length of 0.48 m (1.6 ft) and a small wingspan of 0.76 m (2.5 ft).[37] However, until its extinction, the flightless great auk (Pinguinus impennis) of the North Atlantic, was both the largest alcid and the second largest member of the order.