This isolated tuft of the high ice-crystal cloud Cirrus is of the species spissatus, meaning ‘thickened’ in Latin, because it appears denser than the usual insubstantial appearance of Cirrus. This particular example, which was spotted near Kitt Peak, Arizona, US by Richard Friedman (Member 45,285), very likely started life as the spreading anvil-shaped top of a large and weighty Cumulonimbus storm cloud. As the storm rained or hailed itself away, it would have dissipated from the bottom up until only its upper canopy of ice crystals remained: Cirrus spissatus cumulonimbogenitus, to give it its full and official name, a last drifting vestige of the once-mighty beast of the sky.