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.
Age: Middle-Miocene to Pliocene (approximately 16 to 2.6 million years ago) Megalodon evolved from Carcharocles Subauriculatus sometime in the Miocene, and became extinct at the end of the Pliocene 2.6 million years ago. It is not alive today, and has been dead for millions of years. Tooth Size: Over 7 inches. It has the largest teeth of any shark. Although the largest tooth from megalodon is a a little over 7 inches, A more common size for megalodon teeth is between 3 and 5 inches. Body Size: up to 60 feet and 65 tons.