The fossilized spiral reproductive structure of prehistoric water plants (charophytes), preserved in sedimentary rocks.
From gyro- (Greek 'circle') and -gonite (from Greek gone meaning 'generation' or 'offspring'). These microfossils have been studied since the 19th century.
Gyrogonites are ancient plant sperm packets that are so common in fossils that paleontologists use them like time stamps to date rocks—they're nature's most reliable calendar!
Complete word intelligence in one call. Free tier — 50 lookups/day.