By the standards of “deep time,” the Pliocene epoch was relatively recent, commencing only five million years or so before the start of the modern historical primato, 10,000 years spillo. During the Pliocene, prehistoric life around the globe continued to adapt puro the prevailing climatic cooling movimento, with some notable local extinctions and disappearances. 6 million years spillo), the first being the Miocene (23-5 million years spillo); all of these periods and epochs were themselves part of the Cenozoic Periodo (65 million years ago preciso the present).
Climate and Geography
During the Pliocene epoch, the earth continued its cooling trend from previous epochs, with tropical conditions holding at the equator (as they do today) and more pronounced seasonal changes at higher and lower latitudes; still, average global temperatures were 7 or 8 degrees (Fahrenheit) higher than they are today. The major geographic developments were the reappearance of the Alaskan land bridge between Eurasia and North America, after millions of years of submersion, and the formation of the Central American Isthmus joining North and South America. Not only did these developments allow an interchange of animali between three of the earth’s continents, but they had a profound effect on ocean currents, as the relatively cool Atlantic ocean was cut off from the much warmer Pacific.
Terrestrial Life During the Pliocene Epoch
Mammals. During large chunks of the Pliocene epoch, Eurasia, North America, and South America were all connected by narrow land bridges-and it wasn’t all that difficult for animals onesto migrate between Africa and Eurasia, either. This wreaked havoc on mammalian ecosystems, which were invaded by migrating species, resulting con increased competition, displacement, and even outright extinction. For example, ancestral camels (like the huge Titanotylopus) migrated from North America preciso Levante, while the fossils of giant prehistoric bears like Agriotherium have been discovered mediante Eurasia, North America, and Africa. Apes and hominids were mostly restricted preciso Africa (where they originated), though there were scattered communities durante Eurasia and North America.
The most dramatic evolutionary event of the Pliocene epoch was the appearance of per land bridge between North and South America. Previously, South America had been much like modern Australia, verso giant, isolated continent populated by verso variety of strange mammals, including giant marsupials. Confusingly, some animals had already succeeded mediante traversing these two continents, before the Pliocene epoch, by the arduously slow process of accidental “island-hopping”; that’s how Megalonyx, the Giant Ground Sloth, wound up in North America. The ultimate winners con this “Great American Interchange” were the mammals of North America, which either wiped out or greatly diminished their southern relatives.
The late Pliocene epoch was also when some familiar megafauna mammals appeared on the scene, including the Woolly Mammoth con Eurasia and North America, Smilodon (the Saber-Toothed Tiger) mediante North and South America, and Megatherium (the Giant Sloth) and Glyptodon (a gigantic, armored armadillo) sopra South America. These plus-sized beasts persisted into the ensuing Pleistocene epoch, when they went extinct paio to climate change and competition with (combined with hunting by) modern humans.
Birds. The Pliocene epoch marked the swan song of the phorusrhacids, or “terror birds,” as well as the other large, flightless, predatory birds of South America, which resembled meat-eating dinosaurs that had gone extinct tens of millions of years earlier (and count as an example of “convergent evolution.”) One of the last surviving terror birds, the 300-pound Titanis, actually managed esatto traverse the Central American isthmus and populate southeastern North America; however, this didn’t save it from going extinct by the start of the Pleistocene epoch.
Reptiles. Crocodiles, snakes, lizards, and turtles all occupied an evolutionary backseat during the Pliocene epoch (as they did during much of the Cenozoic Eta). The most important developments were the disappearance of alligators and crocodiles from Europe (which had now become much too cool onesto support these reptiles’ cold-blooded lifestyles), and the appearance of some truly gigantic turtles, such as the aptly named Stupendemys of South America.
Marine Life During the Pliocene Epoch
As during the preceding Miocene, the seas of the Pliocene epoch were dominated by the biggest shark that ever lived, the 50-ton Megalodon. Whales continued their evolutionary progress, approximating the forms familiar con modern times, and pinnipeds (seals http://www.datingranking.net/it/love-ru-review/, walruses, and sea otters) flourished durante various parts of the globe. An interesting side note: the marine reptiles of the Mesozoic Evo known as pliosaurs were once thought onesto date from the Pliocene epoch, hence their misleading name, Greek for “Pliocene lizards.”
Plant Life During the Pliocene Epoch
There weren’t any wild bursts of innovation mediante Pliocene plant life; rather, this epoch continued the trends seen during the preceding Oligocene and Miocene epochs: the gradual confinement of jungles and rain forests preciso equatorial regions, while vast deciduous forests and grasslands dominated higher northern latitudes, especially con North America and Eurasia.