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• Viviparous animals
• Words to Know
• The birth process

Birth, or parturition (pronounced pahr-chuh-RIH-shuhn), in mammals is the process during which a fully developed fetus emerges from the mother's uterus (or womb) by the force of strong, rhythmic muscle contractions. The birth of live offspring is a reproductive feature shared by mammals, some fishes, and certain invertebrates (such as scorpions), as well as some reptiles and amphibians. Animals that give birth to live offspring are called viviparous (pronounced vie-VIP-uh-rus, meaning "live birth").

In contrast to viviparous animals, other animals such as birds and frogs give birth to eggs; these animals are called oviparous (meaning "egg birth"). Still other animals, such as some fish and reptiles, are ovoviviparous, meaning that the young develop in eggs...