The day first became associated with romantic love within the circle of Geoffrey Chaucer in the 14th century, when the tradition of courtly love flourished. In 18th-century England, it grew into an occasion in which couples expressed their love for each other by presenting flowers, offering confectionery, and sending greeting cards (known as “valentines”). Valentine’s Day symbols that are used today include the heart-shaped outline, doves, and the figure of the winged Cupid. Since the 19th century, handwritten valentines have given way to mass-produced greeting cards. In Europe, Saint Valentine’s Keys are given to lovers “as a romantic symbol and an invitation to unlock the giver’s heart”, as well as to children to ward off epilepsy (called Saint Valentine’s Malady).
Megalodon (Carcharocles megalodon), meaning “big tooth”, is an extinct species of shark that lived approximately 23 to 3. 6 million years ago (mya), during the Early Miocene to the Pliocene. It was formerly thought to be a member of the family Lamnidae, and a close relative of the great white shark (Carcharodon carcharias). However, presently there is near unanimous consensus that it belongs to the extinct family Otodontidae, which diverged from the ancestry of the great white shark during the Early Cretaceous. Its genus placement is still debated, authors placing it in either Carcharocles, Megaselachus, Otodus, or Procarcharodon. This is because transitional fossils have been found showing that Megalodon is the final chronospecies of a lineage of giant sharks originally of the genus Otodus which evolved during the Paleocene.