dextro-Transposition of the great arteries (d-Transposition of the great arteries, dextro-TGA, or d-TGA) is a potentially life-threatening birth defect in the large arteries of the heart. The primary arteries (the aorta and the pulmonary artery) are transposed.It is called a cyanotic congenital heart defect (CHD) because the newborn infant turns blue from lack of oxygen. In segmental analysis, this condition is described as ventriculoarterial discordance with atrioventricular concordance, or just ventriculoarterial discordance. d-TGA is often referred to simply as transposition of the great arteries (TGA); however, TGA is a more general term which may also refer to levo-transposition of the great arteries (l-TGA).Another term commonly used to refer to both d-TGA and l-TGA is transposition of the great vessels (TGV), although this term might have an even broader meaning than TGA. Prenatally, a baby with d-TGA experiences no symptoms as the lungs will not be used until after birth, and oxygen is provided by the mother via the placenta and umbilical cord; in order for the red blood to bypass the lungs in utero, the fetal heart has two shunts that begin to close when the newborn starts breathing; these are the foramen ovale and the ductus arteriosus. The foramen ovale is a hole in the atrial septum which allows blood from the right atrium to flow into the left atrium; after birth, the left atrium will be filled with blood returning from the lungs and the foramen ovale will close.
In other animals
The acromion process of bats (Mammalia: Chiroptera) is particularly elongated compared to that of  humans. Turtles have an acromion that forms the anterior part of the triradiate pectoral girdle (together with the coracoid and scapula). In this highly specialized endoskeletal structure, the scapula is a dorsal (directed upwards) process attached to the first rib; the coracoid is a posteroventral (directed backward and down) process; and the acromion is a medioventral (directed inwards and down) process (also known as the prescapular process) located at the base of the scapula. This had led to some controversy regarding the evolutionary origin of turtles, because in both pareiasaurs and non-mammalian therapsids the acromion is located at the dorsal tip of the scapula. In modern turtles, the acromion projects ventrally and articulates with the plastron (the flat lower part of the shell), but it evolved in a common ancestor of pareiasaurs and turtles long before the plastron. In these primitive ancestors, the acromion projected forward to form a strong and flexible articulation between the shoulder girdle and the clavicle. Notwithstanding these changes, the acromion of turtles retains its original function, to support the shoulder girdle and increase stride length. Additional images
Notes
 This article incorporates text in the public domain from page 203 of the 20th edition of Grays Anatomy (1918)

Habermeyer, Peter; Magosch, Petra; Lichtenberg, Sven (2006). Classifications and Scores of the Shoulder. Heidelberg: Springer. ISBN 978-3-540-24350-2. Lee, Michael S. Y. (January 22, 1996). "The Homologies and Early Evolution of the Shoulder Girdle in Turtles". Proc. R. Soc. Lond.