Circulatory system of the horse capacity of the muscular system far exceeds the capacity of the cardiovascular system to deliver oxygen. Blood is made up of red blood cells (erythrocytes) and white blood cells (leukocytes), as well as plasma. Produced in bone marrow, red blood cells are responsible for carrying oxygen to tissue and removing carbon dioxide, all via hemoglobin. White blood cells are used for defense against pathogens in the immune system. Plasma suspends the blood cells, contains clotting factors, and contributes to the greatest volume of blood. The heart and blood vessels contain approximately of blood in a horse, which equates to about
Dinosaur 2009, a team including Schweitzer announced that, using even more careful methodology, they had duplicated their results by finding similar soft tissue in a duck-billed dinosaur, "Brachylophosaurus canadensis", found in the Judith River Formation of Montana. This included even more detailed tissue, down to preserved bone cells that seem even to have visible remnants of nuclei and what seem to be red blood cells. Among other materials found in the bone was collagen, as in the "Tyrannosaurus" bone. The type of collagen an animal has in its bones varies according to its DNA and, in both cases, this collagen was