Latest Jennifer Clack Stories
Nearly everyone can recall the high school textbook illustrations of the planetâ€™s first land-dwelling creatures, ubiquitously represented as comic-looking fish with short, stumpy legs.
New research from Duke University suggests a reversal in the order in which two four-limbed creatures transitioned from water to land.
- A pivoted catch designed to fall into a notch on a ratchet wheel so as to allow movement in only one direction (e.g. on a windlass or in a clock mechanism), or alternatively to move the wheel in one direction.