Report Abuse. An egg lives for around 12 hours after ovulation. Sperm can live for about five days inside the uterus, so providing those two time frames collide, it can be pretty soon after sex.
The tail arrangement is believed to have been a defensive weapon against predators. The term thagomizer was coined by Gary Larson in a 1982 Far Side comic strip, in which a group of cavemen in a faux-modern lecture hall are taught by their caveman professor that the spikes were named for the late Thag Simmons.
The word boogeyman is first attested as bogeyman in the 16th century. It is probably related to the earlier bogle, first appearing in print in 1505 with the sense of ghost. By extension, boogeyman is now used to describe any imaginary or irrational fear, while retaining its original meaning of a monster that terrorizes children.