 As amniotes, reptile eggs are surrounded by membranes for protection and transport, which adapt them to reproduction on dry land.Many of the viviparous species feed their fetuses through various forms of placenta analogous to those of mammals, with some providing initial care for their hatchlings.Extant reptiles range in size from a tiny gecko, "Sphaerodactylus ariasae", which can grow up to to the saltwater crocodile, "Crocodylus porosus", which can reach in length and weigh over .