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.
Smilodon /ËsmaÉªlÉdÉn/ , is an extinct genus of machairodont felid. It is perhaps one of the most famous prehistoric mammals, and the best known saber-toothed cat. It is commonly known as the saber-toothed tiger, although it was not closely related to the tiger or other modern cats. Smilodon lived in the Americas during the Pleistocene epoch (2.5 mya â10,000 years ago).