. "\"The process whose specific outcome is the progression of the hypochord over time, from its formation to the mature structure. The hypochord is a transient rod-like structure in the embryos of fish, lampreys and amphibians that is located immediately ventral to the notochord. The hypochord may play a role in positioning the dorsal aorta.\" [GOC:devbiol, GOC:lb]" . . "hypochord development" . "subnotochordal rod development" . .