German anatomist who first described the embryonic cartilage (now called Meckel's cartilage) that ossifies to form part of the lower jaw in fishes, amphibians, and birds. He also described a pouch (Meckel's diverticulum) of the small intestine.

Meckel, also known as Meckel the Younger, came from a family of physicians. He studied medicine at the universities of Halle and Göttingen, graduating in 1802 after writing a doctoral dissertation on congenital abnormalities of the heart. He was the author of numerous papers and several multivolume treatises, including one on pathological anatomy, and an atlas depicting human abnormalities.