The upcoming discussion will update you about the difference between ratitae and carinate.
Difference # Ratitae:
1. Running birds. The wings are more or less degenerated and not used in flight.
2. The sternum or breast bone is keel less and raft-like.
3. The skull is dromaeognathous, i.e., the vomer is interposed between the palatines, the pterygoids and the basisphenoidal rostrum.
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4. The sutures or the lines of union in the skull remain distinct for a long time.
5. The quadrate articulates with the skull by a single head.
6. The scapula and coracoid are fused and their long axes near the point of union lie almost in the same line or form a very obtuse angle.
7. The clavicles are small or absent.
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8. Except in old Rheas, Emus, the ilium and ischium are not united posteriorly.
9. A pygostyle is never present.
10. The feathers have free barbs and the barbules are without hooks.
11. Except a few, the oil gland is absent.
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12. Pterylae are not regularly arranged.
13. The male has penis.
14. The young birds are always precocious (independent).
Difference # Craniate:
1. Flying birds. The wings are well-developed and almost always used in flight.
2. The sternum or breast bone is provided with a keel.
3. The skull is not dromaeognathous, i.e., the vomer is not fused with the bones of the palate and the palatines articulate with the basisphenoidal rostrum.
4. The sutures or the lines of union in the skull almost always disappear at a very early stage.
5. The quadrate articulates with the skull by a double head.
6. The scapula and coracoid are connected with each other by ligament only and the two bones meet almost at right angles.
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7. The clavicles are well-developed in most cases.
8. The ilium and ischium unite and enclose a sciatic foramen.
9. A pygostyle is usually present.
10. The barbs of the feathers are usually united and the barbules are with hooks.
11. The oil gland is usually present.
12. Pterylae are regularly arranged.
13. The male rarely has a penis.
14. The young birds may be precocious or altrices (dependent).