spiralshaped

Spiral-shaped is a descriptive term used to denote objects that exhibit a spiral geometry, a curve that winds around a central point and either closes upon itself or expands as it revolves. In common usage, it indicates a general spiral form rather than a precise mathematical curve.

In biology, spiral-shaped forms appear across taxa. Gastropod shells, such as those of snails and the nautilus, follow spiral patterns and often approximate a logarithmic spiral as they grow. Some bacteria are described as spiral-shaped, including spirochetes and spirilla, whose helical bodies enable motility. Plant structures also show spiral arrangement, for example in seed heads and leaf phyllotaxis, where seeds or leaves are positioned in spiral patterns around a stem.

In geology and paleontology, spiral shapes appear in ammonoid shells and other fossil forms, reflecting growth patterns over time. In technology and design, spiral geometries are used in coils, springs, spiral staircases, and spiral antennas. Spiral wound gaskets and spiral-channel heat exchangers utilize curved paths that resemble spirals to optimize surface area and flow.

In mathematics, a spiral is a plane curve defined by a relation between radius and angle; common types include the Archimedean spiral and the logarithmic spiral. Real-world spiral-shaped objects often approximate these ideal curves but are not perfect mathematical spirals. The term remains a broad, descriptive label across science, engineering, and design.