Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland.In contrast to excretion, the substance may have a certain function, rather than being a waste product.ecretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland.
The oldest shark fossils. The oldest fossilized evidence of prehistoric sharks comes from shark-like scales that date to 455 million years ago during the Ordovician Period, in Colorado. Some paleontologists do not agree that these scales are sufficiently shark-like to pronounce them sharks.
/ Carcharocles megalodon (abbreviated to C.megalodon) was a huge prehistoric shark that lived between 25 and 1.5 million years ago (the Miocene and Plioc â¦ ene epochs). It is now extinct but no one is sure when C.megalodon died out.