An incision made during labor from the lower end of the vagina toward the anus is called a(n):

An episiotomy

An episiotomy is an incision made during childbirth in the tissue between the vaginal opening and the anus. There are two types of episiotomy incisions which are midline and mediolateral incision. Episiotomy is recommended when a baby is too big or when a baby is lying in an abnormal position. Episiotomy might result in infections, bleeding, painful intercourse and  fecal incontinence after childbirth.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.