Also known as the scapula, it is one of the bone pieces that is related to the thorax and the ribs, so it articulates with some of the latter. In humans, it is one of the first components that give life to the shoulder girdle, located in the upper part of it. Its characteristics and functions can change drastically depending on the species with which it is being treated; one of the most outstanding comparative cases are the discrepancies that can be seen in the bone systems of different species that belong to the same natural division, according to their method of reproduction and anatomy.
Its anterior face is characterized by facing the thorax and having a concave structure in almost all its extension; likewise, it has some surface rough and a projecting on its side. On the contrary, its posterior face is mostly convex and is separated by supraspinatus and infraspinatus fossae. It has three edges in its possession, among which are: the upper edge has physical characteristics that define it as something sharp, thin and short; the medial border, for its part, stands out for being a little longer than the others, as it is very close to the rhomboid muscle; the lateral border, being, basically, a ridge and gives space to one of the scapular arteries.
In creatures other than humans, such as fish, the shoulder blade appears as a bony structure that joins the pectoral fin. Similarly in dinosaurs it was one of the main bones that made up their shoulder girdle, together with the coracoid and clavicle.
