12/30/2023 0 Comments Duck billed platypus baby![]() ![]() 8, 2014-Never-before-published footage shows the mating rituals of echidnas-spiny mammals native to Australia that lay eggs. (See " Pictures: Rare "Cyclops" Shark Found.")įeb. In some sharks that bear live pups, “the mother produces egglets that are not fertilized, and the babies are feeding on them while in the ovary,” says David Reznick, an evolutionary biologist at the University of California, Riverside. Live birth is also rare in fish, accounting for about two percent of known species, including guppies and sharks. Only birds, turtles, and crocodilians bear no live young at all. ![]() (See " Evolution in Action: Lizard Moving from Eggs to Live Birth.") In general, though there are fewer reptiles in higher altitudes and in colder temperatures, proportionately more of them are live-bearing, he adds. ![]() In Australia, yellow-bellied three-toed skinks that live in higher, colder regions bear live young, while those in warmer lowlands lay eggs, which are harder to keep warm under cold conditions. Some reptiles tailor their reproductive strategy depending on where they live. (Related: " Amazing Video: Inside the World's Largest Gathering of Snakes.") Common garter snakes, for example, birth live young, while pythons lay eggs and guard them. ReptilesĪbout 15 to 20 percent of the 9,000 known species of snakes and lizards are live-bearers, Gibbons says. Here's a look at some animals who came to diversify how they multiply. Live bearing means the mother can better protect her developing embryo until it's ready to be born. (See " What Comes Before Snake Sex? A Kama Sutra of Courtship Moves.")īoth methods have their benefits, he says: Egg laying allows greater mobility for the mother who is "not encumbered by large eggs or embryos for a prolonged period," Gibbons says, and a higher likelihood of genetic diversity if there are multiple matings and clutches. Many animal groups have some species that lay eggs and others that birth live young, including fish, amphibians, and yes, even mammals, says Whit Gibbons, evolutionary biologist at the University of Georgia’s Savannah River Ecology Laboratory. While snakes are pretty unique in the animal kingdom, on this one they have to share the spotlight. Licensed under Creative Commons Attribution ShareAlike 2.“Are snakes the only family that evolved multiple birthing options-egg or live birth?” Louis Meluso asked Saturday's Weird Animal Question of the Week. The recent fossil discovery of Akidolestes gives hope to get more insight in the separation of this branch. Its branch is quite separate from any other one known to man. The platypus is one of the closest relatives of ancestral mammals, although it is not itself a link in the chain of mammalian evolution. The platypus has a low body temparature compared to other mammals, it is only 32☌ compared to 38☌. It is unlike we have ever seen, until now! Recent fossil discovery of an extinct species named Akidolestes, a half shrew - half platypus species, challenges conventional wisdom about how placental mammals split from earlier egg-layers. It is very strange: a venomous, duck-billed, egg-laying mammal (?!). ![]() The platypus (Ornithorhynchus anatinus) is a member of the order of monotremata, the egg laying mammals. ![]()
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