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.
Hint: Itâs big. Up to this point, the biggest tooth ever discovered belongs to an extinct killer-whale type species known as Leviathan melvillei. This hunter-whale grew up to 18 meters long, and had the biggest, most lethal teeth in the world, some tooth specimens found reach up to 36 centimeters in length, thatâs over 1 foot long.