Usually, it's because the sperm gets into the fallopian tube before the egg is released. Once there, the sperm wait for an egg to arrive. After fertilization, it can take 5-10 days for the fertilized egg to begin to attach itself to the lining of the uterus. Pregnancy begins when this happens.
The arrangement of spikes originally had no distinct name; the term Thagomizer was coined in 1982 by cartoonist Gary Larson in his comic The Far Side, and thereafter became gradually adopted as an informal term within scientific circles, research, and education.
He named the new element that was producing the green line thallium, after the greek word for 'green twig', thallos. He isolated samples of thallium the next year.Thallium is found in the minerals crooksite (CuThSe), lorandite (TlAsS 2) and hutchinsonite ((Pb, Tl) 2 As 5 S 9), but is usually obtained as a byproduct of the production of sulfuric acid or as a byproduct of refining zinc or lead.istory and Uses: Thallium was discovered spectroscopically by Sir William Crookes, an English chemist, in 1861. Crooks had obtained the sludge left over from the production of sulfuric acid (H 2 SO 4) from a friend.