The upcoming discussion will update you about the difference between reptiles and birds.
Difference # Reptiles:
1. The exoskeleton consists of horny epidermal scales, sometimes provided with bony dermal plates.
2. The central of the vertebrae are usually procoelous.
3. Sacrum when present, its vertebrae (usually two in number) bear large expanded ribs, with the ends of which the ilia articulate.
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4. The cartilaginous sternum may be-come long, but it is never replaced by a membrane bone.
5. Episternum or interclavicle, when present, remains distinct from the clavicle and sternum.
6. The forelimb bears more than three digits and at least three are provided with claws.
7. In the pelvic girdle, the ilium is elongated further behind than in front of the acetabulum. The pubis slopes downward and forward. Pubic and ischiatic symphyses are usually present.
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8. In the hind limb, five digits are often present. The tarsals and metatarsals remain distinct.
9. Sutures in the skull are prominent.
10. The aortic arches are at least two. The heart is four-chambered only in Crocodilia. The posterior part of the body always gets a supply of mixed blood.
11. The body temperature varies with the temperature of the surrounding medium (poikilothermal).
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12. The optic lobes are placed on the upper surface of the brain.
13. Air sac-like structures are present only in Geckos and Chameleons.
14. Both the ovaries and their ducts are present and functional.
Difference # Birds:
1. The exoskeleton consists of a covering of feathers, and there may be a few scales, claws and beak.
2. The central of the vertebrae are usually heterocoelous, having a saddle-shaped terminal curvature.
3. The two sacral vertebrae are without expanded ribs and a long synsacrum is formed by their fusion with other vertebrae.
4. The cartilaginous sternum is replaced by a membrane bone from several centres.
5. Interclavicle, when present, is fused with the clavicles.
6. The forelimb never bears more than three digits and more than two digits are never clawed. The forelimbs are modified as wings, carpals fuse with the fused metacarpals.
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7. The ilium is elongated in front of the acetabulum. The pubis slopes backward parallel to the ischium. Pubic and ischiatic symphyses are very rarely present.
8. In the hind limb, digits are not more than four. The proximal tarsal unites with the tibia forming a tibiotarsus. The first metatarsal, when present, remains free. The other three are fused and fuse with the distal tarsals forming a tarsometatarsus.
9. The sutures in the skull are obliterated.
10. Only the right aortic arch is present. The heart is four-chambered and the body always gets a supply of oxygenated blood.
11. The body temperature is high and almost constant (homeothermal).
12. The optic lobes are placed on the sides of the brain.
13. Air sacs are present.
14. The right ovary and its duct almost atrophies.