Chelonians possess a pair of bones termed coracoids which have no connexion with a sternum; and their scapulae are formed of two widely divergent bars, divided by a deeper notch than is found in any fossil reptiles.
But in mammals the coracoids are nearly always quite vestigial, and the pectoral girdle is attached to the axial skeleton by the clavicle or sometimes by muscles and ligaments only.
Epicoracoidal vestiges of the sternal ends of the coracoids (fig.
The coracoids are large, and the clavicles are nearly always united forming the furcula.
In Lacertilia the coracoids are pierced by fenestrae.
In the shoulder-girdle the coracoids are large and meet in a ventral symphysis; precoracoids and a sternum are apparently absent, but parts generally regarded[71] as the clavicles and interclavicle are well developed.
The pectoral girdle is strongly developed, the scapulae are narrow, the coracoids broad, and meet ventrally without overlapping.
The ventral ends of the coracoids which meet one another in the middle line are unossified, and form narrow strips of calcified cartilage, the =epicoracoids= (fig.
In the Toads (Bufonidae) the epicoracoids or unossified ventral ends of the coracoids and precoracoids overlap in the middle line (fig.
The clavicle is not developed, and the two coracoids overlap in the middle line.
In Chelonia neither the coracoids nor precoracoids meet one another, but their free ends are connected by fibrocartilaginous bands.
In some Lacertilia with degenerate limbs the pectoral girdle is also much reduced, in Ophisaurus apus the ventral borders of the coracoids are widely separated.
The pectoral girdle lies within the ribs, and the precoracoids and coracoids do not meet in ventral symphyses.
In all vertebrata above fish, except the great majority of mammals, the coracoids are large and articulate with the sternum.
But the skeleton is thin and papery, the two coracoids forming a single cartilaginous plate imperfectly divided.
In this family the scapula and coracoidsare ossified, and perhaps the vertebræ also, and, as Dr.
The group has the coracoidsas in Brotulidæ, and the actinosts are united in an undivided plate.
Other variations may occur; the two coracoids sometimes are imperfect or specially modified, the upper sometimes without a foramen, and the actinosts may be distorted in form or position.
The furcula coalesces firmly at its symphysis with the carina of the sternum, and also with the coracoids at the upper extremity of each of its rami, the anterior end of each coracoid coalescing also with the proximal end of the scapula.
In most birds the feet of the coracoids do not touch each other; in some groups they meet, in others one overlaps the other, the right lying ventrally upon the left.
Eventually, when the right and left feet of the coracoids overlap each other, the anterior sternal spine contains a foramen.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "coracoids" in a variety of sentences. We hope that you will now be able to make sentences using this word.
