The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. "True" placentas are a defining characteristic of eutherian or "placental" mammals, but are also found in some snakes and lizards with varying levels of development up to mammalian levels. Note, however, that the homology of such structures in various viviparous organisms is debatable at best and, in invertebrates such as Arthropoda, is definitely analogous at best.
A team of researchers at Penn State University has identified 24 new species of skinks, a subspecies of lizards, native to the Caribbean Islands, turning the region’s fauna from one of the smallest lizard groups in the world to one of the largest. However, half of these new species are considered already extinct or very [...]