This article was originally posted at Stingrays can chew their food, like mammals [toc] Is chewing a unique mammalian feature? Unlike mammals, other animals usually don’t have the ability to chew their food. Chewing can be defined as the interaction of upper and lower teeth by compressing and shearing food in between. And the peculiarity of mammalian chewing is the opposable motion of upper and lower jaw. Chewing is a very recent evolutionary adaptation. There are a few animals along with mammals to do that. Chewing is estimated to have evolved some 60-70 million years during the diversification of mammals. Some scientists even believed chewing one of the key innovations that allowed mammals to flourish, by dining well on insects, grasses, and other abundant sources of food. Now, recent findings using high speed videography has given scientific evidence to show that chewing is not just a mammalian adaptation. Recent study [1] reveals that ocellate river stingray ( Potam...
This article was originally posted at Amazing Zoology Artery Coloured scanning electron micrograph (SEM) of a a small artery (blood vessel) cut open with RBCs (red coloured) rushing outside. Blood Clot Coloured scanning electron micrograph (SEM) of red blood cells (erythrocytes) trapped in a fibrin mesh (yellow). The production of fibrin is triggered by cells called platelets, activated when a blood vessel is damaged. The fibrin binds the various blood cells together, forming a solid structure called a blood clot. A blood clot is a normal response, preventing an excessive loss of blood. However, inappropriate clotting is a major cause of heart attacks and strokes. Red Blood Cells (RBC) They look like little cinnamon candies here, but they are actually the most common type of blood cell in the human body – red blood cells (RBCs). These biconcave-shaped cells have the tall task of carrying oxygen to our entire body; in women there are about 4 to 5 million RBCs per micro liter (cubic...
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