TY - RPRT TI - Late embryonic expansion of a novel bone ridge underlies the evolutionary transformation of cylindrically shaped forelimb bones into the flattened skeleton of the penguin flipper AU - Longtine, C. AU - Grunwald, H. A. AU - Treaster, S. AU - Harris, M. P. AU - Tabin, C. J. PY - 2026 DO - 10.64898/2026.06.29.735166 UR - https://www.biorxiv.org/content/10.64898/2026.06.29.735166v1 ID - 10.64898/2026.06.29.735166 ER -