Is Reptile development internal or external?
Most reptiles reproduce sexually and have internal fertilization. Reptile eggs are amniotic, so they can be laid on land instead of in water. Reptiles do not have a larval stage, and their hatchlings are relatively mature.
What type of development do reptiles have?
Most reptiles are characterized by a period of rapid juvenile growth that slows upon reaching full adulthood. Growth then ceases altogether a few years after maturity. In contrast, some large-bodied species likely have what is known as indeterminate, or attenuated, growth.
Do reptiles have an external covering?
Skin: the outer covering of an animal that protects it from its environment. Reptile scales are made of keratin and are part of a single layer of skin that is shed periodically. Fish have individual bony scales that grow with the animal. Feathers: a structure found in birds that insulates and helps them fly.
What are the external features of reptiles?
Traits of Reptiles and Amphibians
- Reptiles are vertebrates. They have backbones.
- Their bodies are completely covered with scales.
- They are cold-blooded.
- Reptiles produce shelled eggs or bear live young.
- All species fertilize eggs internally.
- All species of reptiles have at least one lung.
What Animals use external development?
Among vertebrates, external fertilization is most common in amphibians and fish. Invertebrates utilizing external fertilization are mostly benthic, sessile, or both, including animals such as coral, sea anemones, and tube-dwelling polychaetes. Benthic marine plants also use external fertilization to reproduce.
Is the development of a reptile internal or external?
Development may be internal, with embryos retained in the female’s oviducts, and embryos of some species may be attached to the mother by a placenta. However, development in most species is external, with embryos enclosed in shelled eggs.
When does embryonic development begin in a reptile?
Embryonic development and parental care Once the eggs are fertilized, development begins, and the egg becomes an embryo as it divides into successively smaller cells. The time delay between fertilization and egg deposition (that is, egg laying) is poorly documented for the majority of reptile species.
How long does it take a reptile to lay an egg?
The time delay between fertilization and egg deposition (that is, egg laying) is poorly documented for the majority of reptile species.
Are there any living reptiles that are live bearers of eggs?
No living crocodiles, turtles, or tuatara are live-bearers. However, in the squamates, live-bearing ranges from retention of unshelled eggs in the oviducts to the development of placentae between the mother and her fetuses. The evolutionary steps from egg laying to placental development are demonstrated by extant species.
Development may be internal, with embryos retained in the female’s oviducts, and embryos of some species may be attached to the mother by a placenta. However, development in most species is external, with embryos enclosed in shelled eggs.
Embryonic development and parental care Once the eggs are fertilized, development begins, and the egg becomes an embryo as it divides into successively smaller cells. The time delay between fertilization and egg deposition (that is, egg laying) is poorly documented for the majority of reptile species.
What kind of fertilization does a reptile have?
Most reptiles reproduce sexually and have internal fertilization. Reptile eggs are amniotic, so they can be laid on land instead of in water. Reptiles do not have a larval stage, and their hatchlings are relatively mature. Reptile parents provide little if any care to their young.
Which is the best description of a reptile?
Reptile, any member of the class Reptilia, the group of air-breathing vertebrates that have internal fertilization, amniotic development, and epidermal scales covering part or all of their body. The major groups of living reptiles—the turtles (order Testudines), tuatara (order Rhynchocephalia [Sphenodontida]),…
