History UsefulNotes / PrehistoricLifeOtherExtinctCreatures

** [[http://en.wikipedia.org/wiki/Primate#Evolution Prehistoric non-hominid primates]]: [[StockPhrase Man-Descended-From-Apes]]. ''[[RunningGag Man-Descended-From-Apes]]''. '''[[OverlyLongGag Man-Descended-From-Apes]]'''. '''''[[ThisIsSparta NO!!!]]''''' Man '''didn't descend''' from apes (that is, chimps, gorillas, orangutans, gibbons): we humans '''and''' chimps/gorillas/orangutans/gibbons all descend from a common ancestor, often called "ape" in popular media but no more closely related to chimps as it was to ourselves. Primate evolution is of particular interest for obvious reasons, but it'd be a too long argumentation here, and would go much beyond the aim of this trope: talking about the most interesting extinct critters. Indeed, most ancient non-hominid primates ''weren't'' particularly interesting compared to their modern descendents: their look was a lot monotonous, some resembled more a lemur, other a tarsier, other a monkey, and other modern apes. However, the primitive ''[[http://en.wikipedia.org/wiki/Plesiadapis Plesiadapis]]'' is worth of note: living at the very start of the Mammal Era, it was a sort of middle way between a squirrel and a monkey, with a lemur-body but gnawing teeth like a rodent. Indeed, it has recently been discovered ''rodents'' are the closest relatives of monkeys and apes. Most prehistoric primates were small like ''Plesiadapis'', although oversized baboons and overgrown lemurs are known in fossil record. But the main exception is ''Gigantopithecus'' (see further).

** ''[[http://en.wikipedia.org/wiki/Andrewsarchus Andrewsarchus]]'': One of the most enigmatic mammals, from the first part of the Cenozoic (the Eocene period). Only a skull is known, 3 ft long and vaguely wolf-like. Some argue it was the largest carnivorous land mammal ever, but we haven't any proof about that; it might be omnivorous instead. It was probably related with the much smaller [[http://en.wikipedia.org/wiki/Mesonychia Mesonychians]], the first meat-eating mammals which obtained a size larger than a house cat; these were once considered the ancestors of whales (see below) because of the shape of their skull that resembles the most primitive cetacean known, ''[[http://en.wikipedia.org/wiki/Pakicetus Pakicetus]]''; now we know [[ScienceMarchesOn hippopotamus]] is the closest relative of whales and dolphins. The fossil record of prehistoric hippos is poorly known; on the other hand, the similar-looking [[http://en.wikipedia.org/wiki/Anthracotheriidae Anthracotheres]] have a rich number of species described, they were probably the closest hippopotamus relatives, or even their ancestors.

** ''[[http://en.wikipedia.org/wiki/Andrewsarchus Andrewsarchus]]'': One of the most enigmatic mammals, from the first part of the Cenozoic (the Eocene period). Only a skull is known, 3 ft long and vaguely wolf-like. Some argue it was the largest carnivorous land mammal ever, but we haven't any proof about that; it might be omnivorous instead. It was probably related with the much smaller [[http://en.wikipedia.org/wiki/Mesonychia Mesonychians]], the first meat-eating mammals which obtained a size larger than a house cat; these were once considered the ancestors of whales (but we'll get to that in a moment) because of the shape of their skull that resembles the most primitive cetacean known, ''[[http://en.wikipedia.org/wiki/Pakicetus Pakicetus]]''; now we know [[ScienceMarchesOn hippopotamus]] is the closest relative of whales and dolphins. The fossil record of prehistoric hippos is poorly known; on the other hand, the similar-looking [[http://en.wikipedia.org/wiki/Anthracotheriidae Anthracotheres]] have a rich number of species described, they were probably the closest hippopotamus relatives or even their ancestors.

** [[http://en.wikipedia.org/wiki/Evolution_of_cetaceans Early whales]]: ''All'' mammals were small and rodent-shaped at their beginnings. Then some became larger and more derived, but none with the same level as whales. The first whale ancestors appeared only 10 million years after the non-avian dinosaurs extinction. ''[[http://en.wikipedia.org/wiki/Ambulocetus Ambulocetus]]'' ("walking whale") is a good example of these: still four-limbed, it was already a good swimmer, but still resembled anything but a whale. Among the first fish-shaped cetaceans, ''[[http://en.wikipedia.org/wiki/Basilosaurus Basilosaurus]]'' reached the length of a modern baleen whale, but was much more slender, almost eel-like. When first discovered, its elongated shape was misidentified for a mosasaur-like marine reptile: hence its strange, dinosaurian-sounding name ("king lizard"). At that time, all whales still were active hunters, like modern killer- and sperm- whales; the first filter-feeders appeared much more recently, when our planet turned colder and immense shoals of krill began to float in polar waters. Other cetaceans, however, remained small and active predators, originating our dolphins. While cetaceans' natural history is now well-known, that of [[http://en.wikipedia.org/wiki/Pinnipedia Pinnipeds]] (seals, sea-lions, walruses etc.) is still poorly-known: we are sure however, they descended from bear-like or otter-like ancestors, and are a more recent group than whales. On the other hand, the third group of sea mammals, [[http://en.wikipedia.org/wiki/Sirenia Sirenians]] (manatees and dugongs), are as ancient as cetaceans, but the first ones already had the shape of the modern ones. There was a forth group of sea-mammal in the Cenozoic, the little-known [[http://en.wikipedia.org/wiki/Desmostylia Desmostylians]], a sort of "herbivorous seals" which looked a bit like walruses but ate weed like hippos and were related with manatees.

** [[http://en.wikipedia.org/wiki/Evolution_of_the_horse Horse ancestors]]: The eternal symbol of Evolution. Almost the same level the Dodo is the icon of extinction. And yet, horse ancestors weren't so cool-looking compared to most other extinct [[http://en.wikipedia.org/wiki/Ungulate hoofed mammals]], really. The most famous of these is, obviously, the [[RuleOfCool less horse-like]] of them all: ''Eohippus'' --> ''Hyracotherium'' --> ''[[http://en.wikipedia.org/wiki/Eohippus Eohippus]]''. An almost-unbelievable ScienceMarchesOn affair has encircled horse's evolution, despite its iconic role in popular-science. Anyway, all this doesn't involve us so much. Expect to see this (whatever name is to be used) small, basal ungulate called ''horse'' anyway, despite it, actually, had nothing more in common with horses than with tapirs or rhinoceri: the "Hyracotheohippus stew" includes several different early ungulates, some of theme ''were'' horse-ancestors and some weren't. Systematics of primitive ungulates (many of them called [[http://en.wikipedia.org/wiki/Condylarthra Condylarths]]) is a total mess.

** [[http://en.wikipedia.org/wiki/Rhinoceros True prehistoric rhinos]]: Modern rhinos are often referred as "prehistoric-looking" in media. Many classic prehistoric mammals were indeed rhino-looking though with different horn-shapes (the aforementioned six-horned ''Uintatherium'' and the fork-horned ''Brontotherium'' are the most well-known examples), but only some of the extinct "rhinoceroses" were ''really'' such. Among them, the most spectacular were the [[http://en.wikipedia.org/wiki/Coelodonta_antiquitatis Woolly Rhino]], the [[http://en.wikipedia.org/wiki/Elasmotherium_sibiricum Unicorn Rhino]], and above all, the Indricothere (ironically, this one wasn't so rhino-looking). The Unicorn (''Elasmotherium sibiricum'') is often confused with the Woolly (''Coelodonta antiquitatis'') because of their similar appearence: however, the latter was not larger than modern white-rhinos and had ''two'' horns as well; the former was much larger (5 tons, like a modern bush elephant) and with one single horn... as long as a grown man, and put on the front rather than upon the nose: hence [[ExactlyWhatItSaysOnTheTin unicorn rhinoceros]]. About Indricotheres, they deserve their own entry below.

** [[http://en.wikipedia.org/wiki/Paraceratherium Indricothere]]: Here is Our Majesty, the largest land mammal ever lived (though some [[ScienceMarchesOn recent research]] seems to indicate that some mammoths were even larger). Despite its really gigantic size - it was as tall as a Brontosaur up to the shoulders, and weighed as ''three'' elephants or, better, as three ''T. rex''es - it still had a quite slender, elegant frame: a sort of muscular giraffe with long neck, small head, and long, slender limbs. Its behavior itself was probably more giraffe-like than elephant-like, browsing the tree tops. In short, it was the new mammalian Brachiosaur. Lived at the middle of the Cenozoic (the Mammal Age). It's also a prime example of IHaveManyNames among prehistoric critters: now called ''Paraceratherium'', its traditional names are ''Indricotherium'' and ''Baluchitherium''.

** The most primitive Ungulates: Once, "ungulates" (hoofed mammals) were believed a natural group of mammals; now ke know that several mammalian lineages reached the ungulate body-plan independently, and they do not make a real ensemble. Those which lived at the beginning of the Cenozoic were rather undifferentiated each other, and did not resemble most modern hoofed mammals. The two most famous are the small "ur-horse" ''Eohippus'' and the large ''Uintatherium'', both from the Eocene epoch: among the other eocenic "ungulates", ''[[http://en.wikipedia.org/wiki/Coryphodon Coryphodon]]'' and ''[[http://en.wikipedia.org/wiki/Phenacodus Phenacodus]]'' are frequently portrayed in books. ''Coryphodon'' was perhaps the first land mammal to exceed 1 ton in weight, and was rather similar to an hippo in shape. ''Phenacodus'' was not larger than a dog: with its several small hoofed digits, it was similar to ''Eohippus'' with a very long tail, and it is often mentioned as the prototypical "basal ungulate". Just like ''Eohippus'', ''Phenacodus'' could have been a possible prey of the famous giant bird ''Gastornis''; while the massive ''Coryphodon'' and ''Uintatherium'' were too powerful to be threatened by any predator when adults, like modern rhinos and elephants.

** ''[[http://en.wikipedia.org/wiki/Andrewsarchus Andrewsarchus]]'': One of the most enigmatic mammals, from the first part of the Cenozoic (the Eocene period). Only a skull is known, 3 ft long and vaguely wolf-like. Some argue it was the largest carnivorous land mammal ever, but we haven't any proof about that; it might be omnivorous instead. It was probably related with the much smaller [[http://en.wikipedia.org/wiki/Mesonychia Mesonychians]], the first meat-eating mammals which obtained a size larger than a house cat; these were once considered the ancestors of whales (see below) because of the shape of their skull that resembles the most primitive cetacean known, ''[[http://en.wikipedia.org/wiki/Pakicetus Pakicetus]]''; now we know [[ScienceMarchesOn hippopotamus]] is the closest relative of whales and dolphins. The fossil record of prehistoric hippos is poorly known; on the other hand, the similar-looking [[http://en.wikipedia.org/wiki/Anthracotheriidae Anthracotheres]] have a rich number of species described, they were probably the closest hippopotamus relatives or even their ancestors.

* ''[[http://en.wikipedia.org/wiki/Confuciusornis Confuciusornis]]'' from Early Cretaceous China had already lost its teeth and shortened its tail, but still retained an old legacy: three-clawed wings. Its similar-looking cousin, ''[[http://en.wikipedia.org/wiki/Jeholornis Jeholornis]]'' from the same habitat, is also, not surprisingly, called ''[[http://en.wikipedia.org/wiki/Shenzhouraptor Shenzhouraptor]]''.

* The first steps: The first post-archaeopteran birds were still a sort of flying dinosaurs. The [[{{Confucius}} phylosophical]] ''[[http://en.wikipedia.org/wiki/Confuciusornis Confuciusornis]]'' from Early Cretaceous China had already lost its teeth and shortened its tail, but still retained an old legacy: three-fingered wings. Its similar-looking cousin, ''[[http://en.wikipedia.org/wiki/Jeholornis Jeholornis]]'' from the same habitat, is also, not surprisingly, called ''[[http://en.wikipedia.org/wiki/Shenzhouraptor Shenzhouraptor]]''.

* [[http://en.wikipedia.org/wiki/Bat Prehistoric bats]]: Just like birds, bats are a very poorly-known group in fossil record, both for the same reason: their skeleton is way too fragile to fossilize well. Despite this, awesomely well-preserved bat remains have been discovered in the most famous fossil deposit from Early Cenozoic: [[http://en.wikipedia.org/wiki/Messel_pit Messel Pit]], in Germany. This deposit has also many, many other early mammals: among them, the aforementioned hopping bug-eater ''Leptictidium'' and the basal ungulate ''[[http://en.wikipedia.org/wiki/Propalaeotherium Propalaeotherium]]'' have been recently made famous by Walking With (even though the propalaeothere ''wasn't'' an early "horse" as said in the program). These and other mammals from this deposit are so well preserved that ''even their fur and stomach contents are known''. In short, we know'em almost like they were still-living animals. The very first bats have been discovered here, and show us all the traits associated with their modern relatives: fingered wings, large ears, and even structure for echolocating are known from these finds. This has lead scientist to make an intriguing hypothesis: perhaps were some sort of gliding proto-bats already living on Earth ''before'' pterosaurs and non-avian dinosaurs disappeared? This would also mean bat-winged critters ''did'' exist at the Age of Dinosaurs, thus making the "Mesozoic bat-winged fliers" thing partially TruthInTelevision.

* [[http://en.wikipedia.org/wiki/Bat Prehistoric bats]]: Ok, we already know it, bats ''are not birds'' at all: but they fit better here for comparison. Just like birds, bats are a very poorly-known group in fossil record, both for the same reason: their skeleton is way too fragile to fossilize well. Despite this, awesomely well-preserved bat remains have been discovered in the most famous fossil deposit from Early Cenozoic: [[http://en.wikipedia.org/wiki/Messel_pit Messel Pit]], in Germany. This deposit has also many, many other early mammals: among them, the aforementioned hopping bug-eater ''Leptictidium'' and the basal ungulate ''[[http://en.wikipedia.org/wiki/Propalaeotherium Propalaeotherium]]'' have been recently made famous by Walking With (even though the propalaeothere ''wasn't'' an early "horse" as said in the program). These and other mammals from this deposit are so well preserved that ''even their fur, feathers and stomach contents are known''. In short, we know'em almost like they were still-living animals. The very first bats have been discovered here, and show us all the traits associated with their modern relatives: fingered wings, large ears, and even structure for echolocating are known from these finds. This has lead scientist to make an intriguing hypothesis: perhaps were some sort of gliding proto-bats already living on Earth ''before'' pterosaurs and non-avian dinosaurs disappeared? This would also mean bat-winged critters ''did'' exist at the Age of Dinosaurs, thus making the "Mesozoic bat-winged fliers" thing partially TruthInTelevision.

** [[http://en.wikipedia.org/wiki/Amphicyonidae Bear-dogs]] and [[http://en.wikipedia.org/wiki/Nimravidae Pseudo-cats]]: Before cat, bears, dogs and hyenas appeared on Earth, there were their pseudo-looking relatives, whose appearence was similar to their successors or a mix of these animals. The aforementioned ''Eusmilus'' was indeed a sabretoothed member of the pseudo-cat family. A [[AllAnimalsAreDogs very dog-like]] "bear-dog" appears in [[WalkingWithDinosaurs WalkingWithBeasts]].

** ''[[http://en.wikipedia.org/wiki/Andrewsarchus Andrewsarchus]]'': One of the most enigmatic mammals, from the first part of the Cenozoic (the Eocene period). Only a skull is known, 3 ft long and vaguely wolf-like. Some argue it was the largest carnivorous land mammal ever, but we haven't any proof about that; it might be omnivorous instead. It was probably related with the much smaller [[http://en.wikipedia.org/wiki/Mesonychia Mesonychians]], the first meat-eating mammals which obtained a size larger than a house cat; these were once considered the ancestors of whales (see below) because of the shape of their skull that resembles the most primitive cetacean known, ''[[http://en.wikipedia.org/wiki/Pakicetus Pakicetus]]''; now we know [[ScienceMarchesOn hippopotamus]] is the closest relative of whales and dolphins. The fossil record of prehistoric hippos is poorly known; on the other hand, the similar-looking[[http://en.wikipedia.org/wiki/Anthracotheriidae Anthracotheres]] have a rich number of species described, they were probably the closest hippopotamus relatives or even their ancestors.

** [[http://en.wikipedia.org/wiki/Evolution_of_cetaceans Early whales]]: ''All'' mammals were small and rodent-shaped at their beginnings. Then some became larger and more derived, but none with the same level as whales. The first whale ancestors appeared only 10 million years after the non-avian dinosaurs extinction. ''[[http://en.wikipedia.org/wiki/Ambulocetus Ambulocetus]]'' ("walking whale") is a good example of these: still four-limbed, it was already a good swimmer, but still resembled anything but a whale. Among the first fish-shaped cetaceans, ''[[http://en.wikipedia.org/wiki/Basilosaurus Basilosaurus]]'' reached the length of a modern baleen whale, but was much more slender, almost eel-like. When first discovered, its elongated shape was misidentified for a mosasaur-like marine reptile: hence its strange, dinosaurian-sounding name ("king lizard"). At that time, all whales still were active hunters, like modern killer- and sperm- whales; the first filter-feeders appeared much more recently, when our planet turned colder and immense shoals of krill began to float in polar waters. Other cetaceans, however, remained small and active predators, originating our dolphins. While cetaceans' natural history is now well-known, that of Pinnipeds (seals, sea-lions, walruses etc.) is still poorly-known: we are sure however, they descended from bear-like or otter-like ancestors, and are a more recent group than whales. On the other hand, the third group of sea mammals, Sirenians (manatees and dugongs), are as ancient as cetaceans, but the first ones already had the shape of the modern ones. There was a forth group of sea-mammal in the Cenozoic, the little-known [[http://en.wikipedia.org/wiki/Desmostylia Desmostylians]], a sort of "herbivorous seals" which looked a bit like walruses but ate weed like hippos and were related with manatees.

** [[http://en.wikipedia.org/wiki/Primate#Evolution Prehistoric non-hominid primates]]: [[StockPhrase Man-Descended-From-Apes]]. ''[[RunningGag Man-Descended-From-Apes]]''. '''[[OverlyLongGag Man-Descended-From-Apes]]'''. '''''[[ThisIsSparta NO!!!]]''''' Man '''didn't descend''' from apes (that is, chimps, gorillas, orangutans, gibbons): we humans '''and''' chimps/gorillas/orangutans/gibbons all descend from a common ancestor, often called "ape" in popular media but no more closely related to chimps as it was to ourselves. Primate evolution is of particular interest for obvious reasons, but it'd be a too long argumentation here, and would go much beyond the aim of this trope: talking about the most interesting extinct critters. Indeed, most ancient non-hominid primates ''weren't'' particularly interesting compared to their modern descendents: their look was a lot monotonous, some resembled more a lemur, other a tarsier, other a monkey, and other modern apes. However, the primitive ''[[http://en.wikipedia.org/wiki/Plesiadapis Plesiadapis]]'' is worth of note: living at the very start of the Mammal Era, it was a sort of middle way between a squirrel and a monkey, with a lemur-body but gnawing teeth like a rodent. Indeed, it has recently been discovered ''rodents'' are the closest relatives of monkeys and apes. Most prehistoric primates were small like ''Plesiadapis'', although oversized baboons and overgrown lemurs are known in fossil record. But the main exception is ''[[http://en.wikipedia.org/wiki/Gigantopithecus Gigantopithecus]]'' (see further).

** [[http://en.wikipedia.org/wiki/Felidae Extinct cats]]: There were dozens kinds of [[http://en.wikipedia.org/wiki/Saber-toothed_cat sabertoothed cats]] in RealLife other than the stock American ''[[StockDinosaurs Smilodon]]'' from the Ice Ages. Some of them are nicknamed according to the form of their fangs: ''[[http://en.wikipedia.org/wiki/Homotherium Homotherium]]'' was the "Scimitar-tooth", ''[[http://en.wikipedia.org/wiki/Megantereon Megantereon]]'' the "dirktooth". While ''[[http://en.wikipedia.org/wiki/Machairodus Machairodus]]'' was the Euro-Afro-Asian sabertoothed equivalent of ''Smilodon'', not to mention [[http://en.wikipedia.org/wiki/Machairodontinae the actual prototype of the group]]; many European paleoartists have considered ''Machairodus'' as the ''real'' stock sabretooth instead of ''Smilodon''. But there were also more familiar-looking cats in the past. The most well-known are the [[http://en.wikipedia.org/wiki/Panthera_leo_atrox American Lion]] and its European cousin, the [[http://en.wikipedia.org/wiki/Panthera_leo_spelaea Cave Lion]], both simply larger, Ice Ages-related subspecies of the modern lion, well adapted to live in colder climates along with the mammoths. While ''[[http://en.wikipedia.org/wiki/Dinofelis Dinofelis]]'', despite resembling more a leopard, was actually a short-fanged saber-toothed cat. A curious thing is, even some prehistoric meat-eating mammals which were not cats at all, developed a bewildering "sabre-toothed" look ''before'' true cats appeared: two main examples are the pseudo-cat ''[[http://en.wikipedia.org/wiki/Eusmilus Eusmilus]]'' and the marsupial ''[[http://en.wikipedia.org/wiki/Thylacosmilus Thylacosmilus]]'', in particular the latter, being closer to ''kangaroos'' than to cats.

** ''[[http://en.wikipedia.org/wiki/Brontotherium Brontotherium]]'': This is the prototype of its group of mammals, the [[ExactlyWhatItSaysOnTheTin brontotheres]], whose cool name means "thunder beasts". While ''Uintatherium'' was not related with any modern hoofed mammals, Brontotheres were distant relatives of [[http://en.wikipedia.org/wiki/Perissodactyla horses, tapirs and rhinos]]. They had a more rhino-like look than uintathere, having one single "horn" on their nose: ''Brontotherium'' 's prominence was forked and slingshot-like, while that of ''[[http://en.wikipedia.org/wiki/Embolotherium Embolotherium]]'' (the brontothere portrayed in [[WalkingWithDinosaurs Walking With Beasts) was shovel-like and not forked. Like uintathere, brontotheres too roamed plains of the Northern Continents in huge numbers in Early Cenozoic: then they eventually gone extinct, perhaps because they weren't capable to adapt to the diffusion of the very first grasslands which replaced their former food (made of scrub and non-grass herbs).

** [[http://en.wikipedia.org/wiki/Rhinoceros True prehistoric rhinos]]: Modern rhinos are often referred as "prehistoric-looking" in media. Many classic prehistoric mammals were indeed rhino-looking though with different horn-shapes (the aforementioned six-horned ''Uintatherium'' and the fork-horned ''Brontotherium'' are the most well-known examples), but only some of the extinct "rhinoceroses" were ''really'' such. Among them, the most spectacular were the [[http://en.wikipedia.org/wiki/Coelodonta_antiquitatis Woolly Rhino]], the [[http://en.wikipedia.org/wiki/Elasmotherium_sibiricum Unicorn Rhino]], and above all, the [[http://en.wikipedia.org/wiki/Paraceratherium Indricothere]] (ironically, this one wasn't so rhino-looking). The Unicorn (''Elasmotherium sibiricum'') is often confused with the Woolly (''Coelodonta antiquitatis'') because of their similar appearence: however, the latter was not larger than modern white-rhinos and had ''two'' horns as well; the former was much larger (5 tons, like a modern bush elephant) and with one single horn... as long as a grown man, and put on the front rather than upon the nose: hence [[ExactlyWhatItSaysOnTheTin unicorn rhinoceros]]. About Indricotheres, they deserve their own entry below.

** [[http://en.wikipedia.org/wiki/Proboscidea Other elephant relatives]]: There were A LOT of them in Prehistory: not so in {{Prehistoria}}. Don't expect to see any proboscidean in TV outside docus unless it's a Woolly Mammoth or an [[StockDinosaurs American Mastodon]], even though many of them were far cooler-looking than the latter. If you don't believe us, take a look on these: the shovel-jawed ''[[http://en.wikipedia.org/wiki/Platybelodon Platybelodon]]'' resembled a cross between an elephant and a hippo. The huge ''[[http://en.wikipedia.org/wiki/Deinotherium Deinotherium]]'' had two tusks ''on the lower jaw''. The ancestral ''[[http://en.wikipedia.org/wiki/Moeritherium Moeritherium]]'' (classicaly mentioned as "the first elephant") didn't resemble even an elephant: with its short trunk and short limbs, it was more similar to a modern tapir. But even more normally-looking proboscideans would appear cool-looking by our standards: other than the aforementioned giant mammoths, see the [[http://en.wikipedia.org/wiki/Anancus European Mastodon]] and its sword-like tusks, just as as example. And oh, don't forget some island-dwellers which lived in the Ice Ages and almost managed to survive until human history: the oxymoronic [[http://en.wikipedia.org/wiki/Dwarf_elephant Dwarf Elephants]]. Yes, they were real, and some ''sheep-sized''. Many of the larger elephant and elephant-relative bones (and the smaller ones too) which were found int he Mediterranean were identified by the ancient Greeks as the remaining bones of monsters, heroes and animals from the [[ClassicalMythology Age of Heroes.]] Some of these bones were identified as Cyclopes, but no elephant skulls were. The Fossils of Anceint Greece are way to fragment due to geologic forces (earthquakes and volcanoes) to allow something as fragile as a skull to survive intact.

** [[http://en.wikipedia.org/wiki/Mammuthus Giant mammoths]]: It is often heard the mammoth was bigger than a modern elephant. This is not true if we consider the stock guy, the hairy, curly-tusked tundra-dweller called "Woolly mammoth" all people know: but this ''is'' true talking about other mammoth species. There were indeed ''many'' species of mammothes in RealLife, and as a group they lived across most of the Ice-Ages world. The largest ones did challenge the "indricothere" (see later) as the "Biggest land mammal ever" title, but only if you count their weight (the indricothere would ever be taller than every mammoth, thanks to its giraffe-like body frame). The most famous are two American species, the [[http://en.wikipedia.org/wiki/Mammuthus_imperator Imperial mammoth]] and the southerner [[http://en.wikipedia.org/wiki/Mammuthus_columbi Columbian Mammoth]]; giant mammothes have been discovered in the famous US tar-pits like [[http://en.wikipedia.org/wiki/La_Brea_Tar_Pits La Brea]] along with sabertooths and many other animals, some of them still-living today and other extinct after the Ice Ages. Other mammothes as large as the latter were the Asian [[http://en.wikipedia.org/wiki/Mammuthus_trogontherii Steppe Mammoth]] and the less-known but possibly the largest of them all, ''[[http://en.wikipedia.org/wiki/Mammuthus_sungari Mammuthus sungari]]''. The lower popularity of the giant mammothes (despite their size) compared to the woolly one is probably due to their more normal, less-spectacular appearence. They were more similar-looking to modern elephants than to the popular image of "the mammoth" because they were mostly hairless and with classic-shaped tusks (though longer than modern bush elephants); this because they inhabited relatively warmer climates, and their greater size was enough to preserve heat without the woolly covering.

** [[http://en.wikipedia.org/wiki/Proboscidea Other elephant relatives]]: There were A LOT of them in Prehistory: not so in {{Prehistoria}}. Don't expect to see any proboscidean in TV outside docus unless it's a [[StockDinosaurs Woolly Mammoth or an American Mastodon]], even though many of them were far cooler-looking than the latter. If you don't believe us, take a look on these: the shovel-jawed ''[[http://en.wikipedia.org/wiki/Platybelodon Platybelodon]]'' resembled a cross between an elephant and a hippo. The huge ''[[http://en.wikipedia.org/wiki/Deinotherium Deinotherium]]'' had two tusks ''on the lower jaw''. The ancestral ''[[http://en.wikipedia.org/wiki/Moeritherium Moeritherium]]'' (classicaly mentioned as "the first elephant") didn't resemble even an elephant: with its short trunk and short limbs, it was more similar to a modern tapir. But even more normally-looking proboscideans would appear cool-looking by our standards: other than the aforementioned giant mammoths, see the [[http://en.wikipedia.org/wiki/Anancus European Mastodon]] and its sword-like tusks, just as as example. And oh, don't forget some island-dwellers which lived in the Ice Ages and almost managed to survive until human history: the oxymoronic [[http://en.wikipedia.org/wiki/Dwarf_elephant Dwarf Elephants]]. Yes, they were real, and some ''sheep-sized''. Many of the larger elephant and elephant-relative bones (and the smaller ones too) which were found int he Mediterranean were identified by the ancient Greeks as the remaining bones of monsters, heroes and animals from the [[ClassicalMythology Age of Heroes.]] Some of these bones were identified as Cyclopes, but no elephant skulls were. The Fossils of Anceint Greece are way to fragment due to geologic forces (earthquakes and volcanoes) to allow something as fragile as a skull to survive intact.

* [[http://en.wikipedia.org/wiki/Scorpiones True Scorpions]], [[http://en.wikipedia.org/wiki/Spider Spiders]] and [[http://en.wikipedia.org/wiki/Myriapoda Milli/Centipedes]]: The very first animals which made their first steps onto dryland weren't vertebrates, but Arthropods. It's easy to understand why. At the Silurian, vertebrates still were all fish-like and their fins weren't articulated structures which could make a leverage to substain the body constrasting the force of gravity; while Arthropods have had articulated legs since the Cambrian, 100 million years before. Thus, they were in clear advantage. The very first land arthropods weren't insects though; the latter have been a more recent appearence within Evolution. The first colonizer were the "Myriapods" (millipedes, centipedes and their extinct kin) and the [[http://en.wikipedia.org/wiki/Chelicerata "Chelicerates"]]. The latter include, other than Spiders and Scorpions, the aforementioned "Horseshoe-crabs" and "Sea-Scorpions" which remained aquatic animals. We are not sure how arthropods managed to reach the land, but we know for sure that myriapods and "true" scorpions were already present in the Silurian, while the first known spiders appeared much later, only in the Carboniferous (contemporary to the very first reptiles). All these invertebrates were astonishingly similar to their today-descendants, to the point that the latter may be counted as real "living fossils". Most prehistoric land-living arthropods remained as small as they still are today, but some grew larger: expecially in the Carboniferous, and we'll discover why just in that period. Generally, Paleozoic land arthropods tend to be represented in a very generic way in fiction or documentaries, typically lived-interpreted by actual animals. For example, the series ''[[WalkingWithDinosaurs Walking With Monsters]]'' portrayed a land-scorpion in the Devonian (perhaps ''[[http://en.wikipedia.org/wiki/Palaeophonus Palaeophonus]]''), live-acted by a modern scorpion species. However, the same series has made perhaps the first example in TV of documentary-related arthropods in CGI. Other than trilobites and eurypterids, we can see the large, still semi-aquatic scorpion ''[[http://en.wikipedia.org/wiki/Brontoscorpio Brontoscorpio]]'' in the Silurian (imprecisely described as a "Sea-Scorpion", [[TaxonomicTermConfusion making to believe]] it was a ''Pterygotus'' relative...); in Carboniferous settings, the large, fully-terrestrial scorpion ''[[http://en.wikipedia.org/wiki/Pulmonoscorpius Pulmonoscorpius]]'' appears (unnamed), as well as the giant spider "Megarachne" - considered the largest spider ever at the time, but its fossil has later revealed actually to be an [[ScienceMarchesOn eurypterid]]; thus not a spider, and not even ''land-living''. The latter has been perhaps the most awesome case of RuleOfCool within the entire Walking With series: with its creepy ''[[DarkIsEvil black venom]]'', it destroys a nest full of young protoreptiles ''apparently for mere vengeance'', and if it was not enough, it seems ''laughing sadistically upon its victims'' [[WallBanger while the narrator saying THE ARTHROPODS ARE BACK!]]. Not to mention those awe-inspiring "giant ants" in ''Beasts'' - these were discovered in the same Messel Pits in which the first bats have been discovered, but their behaviour as it appears in the docu is ''totally speculative'', mind you. Nonetheless, the absolute stars of the series among CGI land-arthropods were two ''really'' big Carboniferous animals: the proto-millipede ''[[http://en.wikipedia.org/wiki/Arthropleura Arthropleura]]'' and the proto-dragonfly ''[[http://en.wikipedia.org/wiki/Meganeura Meganeura]]''.

** [[http://en.wikipedia.org/wiki/Proboscidea Other elephant relatives]]: There were A LOT of them in Prehistory: not so in {{Prehistoria}}. Don't expect to see any proboscidean in TV outside docus unless it's a [[StockDinosaurs Woolly Mammoth or an American Mastodon]], even though many of them were far cooler-looking than the latter. If you don't believe us, take a look on these: the shovel-jawed ''[[http://en.wikipedia.org/wiki/Platybelodon Platybelodon]]'' resembled a cross between an elephant and a hippo. The huge ''[[http://en.wikipedia.org/wiki/Deinotherium Deinotherium]]'' had two tusks ''on the lower jaw''. The ancestral ''[[http://en.wikipedia.org/wiki/Moeritherium Moeritherium]]'' (classicaly mentioned as "the first elephant") didn't resemble even an elephant: with its short trunk and short limbs, it was more similar to a modern tapir. But even more normally-looking proboscideans would appear cool-looking by our standards: other than the aforementioned giant mammoths, see the [[http://en.wikipedia.org/wiki/Anancus European Mastodon]] and its sword-like tusks, just as as example. And oh, don't forget some island-dwellers which lived in the Ice Ages and almost managed to survive until human history: the oxymoronic [[http://en.wikipedia.org/wiki/Dwarf_elephant Dwarf Elephants]]. Yes, they were real, and some ''sheep-sized''. Many of the larger elephant and elephant-relative bones (and the smaller ones too) which were found int he Mediterranean were identified by the ancient greeks as the remaining bones of monsters, heroes and animals from the [[ClassicalMythology Age of Heroes.]] Some of these bones were identified as Cyclopes, but no elephant skulls were. The Fossils of Anceint Greece are way to fragment due to geologic forces (earthquakes and volcanoes) to allow something as fragile as a skull to survive intact.

** [[http://en.wikipedia.org/wiki/Proboscidea Other elephant relatives]]: There were A LOT of them in Prehistory: not so in {{Prehistoria}}. Don't expect to see any proboscidean in TV outside docus unless it's a [[StockDinosaurs Woolly Mammoth or an American Mastodon]], even though many of them were far cooler-looking than the latter. If you don't believe us, take a look on these: the shovel-jawed ''[[http://en.wikipedia.org/wiki/Platybelodon Platybelodon]]'' resembled a cross between an elephant and a hippo. The huge ''[[http://en.wikipedia.org/wiki/Deinotherium Deinotherium]]'' had two tusks ''on the lower jaw''. The ancestral ''[[http://en.wikipedia.org/wiki/Moeritherium Moeritherium]]'' (classicaly mentioned as "the first elephant") didn't resemble even an elephant: with its short trunk and short limbs, it was more similar to a modern tapir. But even more normally-looking proboscideans would appear cool-looking by our standards: other than the aforementioned giant mammoths, see the [[http://en.wikipedia.org/wiki/Anancus European Mastodon]] and its sword-like tusks, just as as example. And oh, don't forget some island-dwellers which lived in the Ice Ages and almost managed to survive until human history: the oxymoronic [[http://en.wikipedia.org/wiki/Dwarf_elephant Dwarf Elephants]]. Yes, they were real, and some ''sheep-sized''. And those that lived in the Mediterranean might even have inspired the mythical ''Cyclops'': their skull, with the nasal opening put just in the place human orbits would be, may have resembled to ancient Greeks that of a single-eyed giant man.

** ''[[http://en.wikipedia.org/wiki/Andrewsarchus Andrewsarchus]]'': One of the most enigmatic mammals, from the first part of the Cenozoic (the Eocene period). Only a skull is known, 3 ft long and vaguely wolf-like. Some argue it was the largest carnivorous land mammal ever, but we haven't any proof about that; it might be omnivorous instead. It was probably related with the much smaller [[http://en.wikipedia.org/wiki/Mesonychia Mesonychians]], the first meat-eating mammals which obtained a size larger than a house cat; these were once considered the ancestors of whales (see below) because of the shape of their skull that resembles the most primitive cetacean known, ''[[http://en.wikipedia.org/wiki/Pakicetus Pakicetus]]''; now we know [[ScienceMarchesOn hippopotamus]] is the closest relative of whales and dolphins.

** [[http://en.wikipedia.org/wiki/Proboscidea Other elephant relatives]]: There were A LOT of them in Prehistory: not so in {{Prehistoria}}. Don't expect to see any proboscidean in TV outside docus unless it's a [[StockDinosaurs Woolly Mammoth or an American Mastodon]], even though many of them were far cooler-looking than the latter. If you don't believe us, take a look on these: the shovel-jawed ''[[http://en.wikipedia.org/wiki/Platybelodon Platybelodon]]'' resembled a cross between an elephant and a hippo. The huge ''[[http://en.wikipedia.org/wiki/Deinotherium Deinotherium]]'' had two tusks ''on the lower jaw''. The ancestral ''[[http://en.wikipedia.org/wiki/Moeritherium Moeritherium]]'' (classicaly mentioned as "the first elephant") didn't resemble even an elephant: with its short trunk and short limbs, it was more similar to a modern tapir. But even more normally-looking proboscideans would appear cool-looking by our standards: other than the aforementioned giant mammoths, see the [[http://en.wikipedia.org/wiki/Anancus European Mastodon]] and its sword-like tusks, just as as example. And oh, don't forget some island-dwellers which lived in the Ice Ages and almost managed to survive until human history: the oxymoronic [[http://en.wikipedia.org/wiki/Dwarf_elephant Dwarf Elephants]]. Yes, they were real, and some ''sheep-sized''. And those living in the Mediterranean might even have inspired the mythical Cyclops: their skull, with the nasal opening put just in the place human orbits are places, resembled that of a single-eyed giant man to ancient Greek people.

** [[http://en.wikipedia.org/wiki/Proboscidea Elephant relatives]]: There were A LOT of them in Prehistory: not so in {{Prehistoria}}. Don't expect to see any proboscidean in TV outside docus unless it's a [[StockDinosaurs Mammoth or an American Mastodon]], even though many of them were far cooler-looking than the latter. If you don't believe us, take a look on these: the shovel-jawed ''[[http://en.wikipedia.org/wiki/Platybelodon Platybelodon]]'' resembled a cross between an elephant and a hippo. The huge ''[[http://en.wikipedia.org/wiki/Deinotherium Deinotherium]]'' had two tusks ''on the lower jaw''. The ancestral ''[[http://en.wikipedia.org/wiki/Moeritherium Moeritherium]]'' (classicaly mentioned as "the first elephant") didn't resemble even an elephant: with its short trunk and short limbs, it was more similar to a modern tapir. But even more normally-looking proboscideans would appear cool-looking by our standards: see the [[http://en.wikipedia.org/wiki/Anancus European Mastodon]] and its sword-like tusks, just as as example. And oh, don't forget some island-dwellers which lived in the Ice Ages and almost managed to survive until human history: the oxymoronic [[http://en.wikipedia.org/wiki/Dwarf_elephant Dwarf Elephants]]. Yes, they were real, and some ''sheep-sized''.

** [[http://en.wikipedia.org/wiki/Felidae Extinct cats]]: There were dozens kinds of [[http://en.wikipedia.org/wiki/Saber-toothed_cat sabertoothed cats]] in RealLife. Some of them are nicknamed according to the form of their fangs: ''[[http://en.wikipedia.org/wiki/Homotherium Homotherium]]'' was the "Scimitar-tooth", ''[[http://en.wikipedia.org/wiki/Megantereon Megantereon]]'' the "dirktooth". While ''[[http://en.wikipedia.org/wiki/Machairodus Machairodus]]'' was the Euro-Afro-Asian sabertoothed equivalent of ''[[StockDinosaurs Smilodon]]'', not to mention [[http://en.wikipedia.org/wiki/Machairodontinae the actual prototype of the group]]; many European paleoartists have considered ''Machairodus'' as the ''real'' stock sabretooth instead of ''Smilodon''. But there were also more familiar-looking cats in the past. The most well-known are the [[http://en.wikipedia.org/wiki/Panthera_leo_atrox American Lion]] and its European cousin, the [[http://en.wikipedia.org/wiki/Panthera_leo_spelaea Cave Lion]], both simply larger, Ice Ages-related subspecies of the modern lion, well adapted to live in colder climates along with the mammoths. While ''[[http://en.wikipedia.org/wiki/Dinofelis Dinofelis]]'', despite resembling more a leopard, was actually a short-fanged saber-toothed cat. A curious thing is, even some prehistoric meat-eating mammals which were not cats at all, developed a bewildering "sabre-toothed" look ''before'' true cats appeared: two main examples are the pseudo-cat ''[[http://en.wikipedia.org/wiki/Eusmilus Eusmilus]]'' and the marsupial ''[[http://en.wikipedia.org/wiki/Thylacosmilus Thylacosmilus]]'', in particular the latter, being closer to ''kangaroos'' than to cats.

** [[http://en.wikipedia.org/wiki/Megatherium Giant Ground Sloths]]: Some of them were among the hugest land mammals ever lived, but many others weren't so giant-things (even though still large by human standards). Very strongly-built and weaponed with enormous claws, they were capable to walk around with their body upright, a bit like giant bears. Being members of the [[http://en.wikipedia.org/wiki/Xenarthra Xenarthran]] group, they were prevalently South American (some of them migrated to the North however) and had primitive teeth: nonetheless, they were so well-adapted to their environments that they flourished for almost the entire length of the Mammal-Ages: they got mysteriously extinct only few thousand years ago. The colossal ''[[http://en.wikipedia.org/wiki/Megatherium Megatherium]]'' is the prototypical giant ground sloth, was ''elephant-sized'', reached 5 m when fully erect, and its name means...well... [[ExactlyWhatItSaysOnTheTin big beast]].

** Prehistoric [[http://en.wikipedia.org/wiki/Canidae canids]] and [[http://en.wikipedia.org/wiki/Hyaenidae hyenas]]: Prehistoric wolves and hyenas were not so different-looking than ours, but sometimes were larger. The [[http://en.wikipedia.org/wiki/Canis_dirus Dire Wolf]] has been often found in the same tarpits in which ''Smilodon'' remains have been discovered, along with several other American mammals (elephant relatives, ground sloth, but modern-living mammals as well); the most famous is [[http://en.wikipedia.org/wiki/La_Brea_Tar_Pits Rancho la Brea]], within Los Angeles. Among extinct hyenas we can mention the [[http://en.wikipedia.org/wiki/Cave_hyena Cave Hyena]], similar to modern spotted hyenas but living in northern territories during the Ice Ages. Some extinct canid were deceptively hyena-like: ''[[http://en.wikipedia.org/wiki/Borophagus Osteoborus]]'' from Middle Cenozoic is one example.

** [[http://en.wikipedia.org/wiki/http://en.wikipedia.org/wiki/Ground_sloth Giant Ground Sloths]]: Some of them were among the hugest land mammals ever lived, but many others weren't so giant-things (even though still large by human standards). Very strongly-built and weaponed with enormous claws, they were capable to walk around with their body upright, a bit like giant bears. Being members of the [[http://en.wikipedia.org/wiki/Xenarthra Xenarthran]] group, they were prevalently South American (some of them migrated to the North however) and had primitive teeth: nonetheless, they were so well-adapted to their environments that they flourished for almost the entire length of the Mammal-Ages: they got mysteriously extinct only few thousand years ago. The colossal ''[[http://en.wikipedia.org/wiki/Megatherium Megatherium]]'' is the prototypical giant ground sloth, was ''elephant-sized'', reached 5 m when fully erect, and its name means...well... [[ExactlyWhatItSaysOnTheTin big beast]].

** Prehistoric hominids: [[{{Gandhi}} Until he extends the circle of compassion to all living things, man will not himself find peace]]. That's why this paragraph is at the bottom of the Mammal section. Technically [[PunyHumans a subset of Primates]], hominids is a group of animals somewhat controversial to talk about, for obvious ethical reasons: so we'll talk only about those which were not clearly human like us, and let's end our TimeTravel with australopithecines. The hominid group itself fluctuates in definition, going from all beings closer to us that to chimps, to all things closer to us that to baboons; the most widely accepted use includes the great apes; that's is, all beings closer to us that to gibbons, and that's the one to be used here. Anyway, this family split off from gibbons about 15 million years ago, and not long after, it split off in two main branches: The Asian branch, nowadays made up of the 2 species of orangutan; and the African branch, which includes gorillas, chimps and us. Focusing in that latter branch, the branch gorillas belong to splits off from the main branch 7 million years ago, and the chimp branch splits from the branch that would lead to us shortly after. That latter branch was subject to selective pressure due to having to adapt to the harshed savannah environment: The 2 modern chimp species split from each other at roughly the same time our branch split from Lucy (see below).

** [[http://en.wikipedia.org/wiki/Primate#Evolution Prehistoric primates]]: [[StockPhrase Man-Descended-From-Apes]]. ''[[RunningGag Man-Descended-From-Apes]]''. '''[[OverlyLongGag Man-Descended-From-Apes]]'''. '''''[[ThisIsSparta NO!!!]]''''' Man '''didn't descend''' from apes (that is, chimps, gorillas, orangutans, gibbons): we humans '''and''' chimps/gorillas/orangutans/gibbons all descend from a common ancestor, often called "ape" in popular media but no more closely related to chimps as it was to ourselves. Primate evolution is of particular interest for obvious reasons, but it'd be a too long argumentation here, and would go much beyond the aim of this trope: talking about the most interesting extinct critters. Indeed, most ancient non-hominid primates ''weren't'' particularly interesting compared to their modern descendents: their look was a lot monotonous, some resembled more a lemur, other a tarsier, other a monkey, and other modern apes. However, the primitive ''[[http://en.wikipedia.org/wiki/Plesiadapis Plesiadapis]]'' is more interesting: living at the very start of the Mammal Era, it was a sort of middle way between a squirrel and a monkey, with a lemur-body but gnawing teeth like a rodent. Indeed, it has recently been discovered ''rodents'' are the closest relatives of monkeys and apes. Most prehistoric primates were small like ''Plesiadapis'', although oversized baboons and overgrown lemurs are known in fossil record. But the main exception it this: ''[[http://en.wikipedia.org/wiki/Gigantopithecus Gigantopithecus]]''. Its name means "giant ape", and with reason. An orangutan relative, the shape of its teeth show us it was a plant-eater, but.... it was ''two times'' bigger than a modern silverback gorilla: a sort of middle-way between a Real-life gorilla and KingKong. Not only that, it was discovered near the Himalayas: could it be the mythical [[BigfootSasquatchAndYeti Yeti]]? If so, this would mean it could be ''still alive'' (don't be too excited: experts say it's ''highly improbable'' that such a large animal has remained unobserved for such a long amount of time...). Sadly, the only certain thing we know about it is just a lower fossil jaw.

** Mammals of prehistoric Australia: Australian mammalofauna hasn't changed much since the non-avian dinosaur extinction (not counting human influence of course): there have always been [[http://en.wikipedia.org/wiki/Marsupialia marsupials]] and [[http://en.wikipedia.org/wiki/Monotremata monotremes]] in the LandDownunder. Since modern Australian mammals are already so bizarre-looking, how would their predecessors have looked? Not unlike their descendents, really; but some were a bit larger. [[http://en.wikipedia.org/wiki/Procoptodon Giant Kangaroos]] were 10 ft tall, with a short tail and a flat snout; while [[http://en.wikipedia.org/wiki/Diprotodon Diprotodonts]] were even larger, ''rhino-sized'', but were wombat relatives, and thus vegetarian. Monotremes too were amazing: the [[http://en.wikipedia.org/wiki/Zaglossus Giant Echidna]] was as large as a sheep. Nevertheless, there was also an unique animal which has no modern relatives: the [[http://en.wikipedia.org/wiki/Thylacoleo Marsupial Lion]], so-called because of its body-shape and sharp claws, but with ''rodent-like incisors'' instead of the classic fangs. Scientist thought it was indeed vegetarian; now they know it was predatory, just like another unusual marsupial from South America: the aforementioned "marsupial sabretooth", ''[[http://en.wikipedia.org/wiki/Thylacosmilus Thylacosmilus]]''. Yes, there weren't only possums, once, in South America.

[[folder:Hominids]]

[[{{Gandhi}} Until he extends the circle of compassion to all living things, man will not himself find peace]]. That's why our direct ancestors are at the bottom of the Useful Notes. Technically [[PunyHumans a subset of Primates]], hominids is a group of animals somewhat controversial to talk about, for obvious ethical reasons: so we'll talk only about those which were not clearly human like us, and let's end our TimeTravel with australopithecines. The hominid group itself fluctuates in definition, going from all beings closer to us that to chimps, to all things closer to us that to baboons; the most widely accepted use includes the great apes; that's is, all beings closer to us that to gibbons, and that's the one to be used here. Anyway, this family split off from gibbons about 15 million years ago, and not long after, it split off in two main branches: The Asian branch, nowadays made up of the 2 species of orangutan; and the African branch, which includes gorillas, chimps and us. Focusing in that latter branch, the branch gorillas belong to splits off from the main branch 7 million years ago, and the chimp branch splits from the branch that would lead to us shortly after. That latter branch was subject to selective pressure due to having to adapt to the harshed savannah environment: The 2 modern chimp species split from each other at roughly the same time our branch split from Lucy (see below).

* Extinct Apes: Due to jungles not being good places for fossilization, not many species of extinct apes are known. The most notable one is the aforementioned ''[[http://en.wikipedia.org/wiki/Gigantopithecus Gigantopithecus]]'', a relative of the orangutan (that also exhibited gorilla-like characters), measuring up to 10 feet when standing upright. A species of extinct human, ''Homo erectus'', quite likely met this astonishing creature, but that's the closest contact this animal had with humanity: some experts think competition with ''the giant panda'' drove it to extinction. Other extinct apes were once considered true human ancestors, or at least the common ancestors of apes and humans, but now are believed only distant relatives which shared some apparently human-like traits. ''[[http://en.wikipedia.org/wiki/Proconsul Proconsul]]'', ''[[http://en.wikipedia.org/wiki/Dryopithecus Dryopithecus]]'', and "Ramapithecus" (now ''[[http://en.wikipedia.org/wiki/Sivapithecus Sivapithecus]]'') are often mentioned in old textbook for this, but now their relevance is drastically fallen down.

** ''[[http://en.wikipedia.org/wiki/Australopithecus Australopithecus]]'' and its kin: In the past, all the closest relatives of the genus ''Homo'' were put in this genus: now this is not such anymore. The beings included in this evolutionary grade are generally ape-like, being to the rest of apes what baboons are to other old-world monkeys: savannah-adapted relatives of a mostly forest-living group. As we get torwards modern times, the species of australopithecines become steadily more bipedal, adapt their feet to ground locomotion, and generally become more human-like. Recent taxonomical revisions have split off 2 other significant genera from ''Australopithecus'': the earlier ''[[http://en.wikipedia.org/wiki/Ardipithecus Ardipithecus]]'', and the robust, man sized ''[[http://en.wikipedia.org/wiki/Paranthropus Paranthropus]]''. Significant species of Australopithecus are ''A. afarensis'', best known for the specimen known as [[TheBeatles Lucy]]; and ''A. africanus'' (the first discovered, in 1925), likely an ancestor of the genus ''Homo''. But this is another story.

** ''Homo habilis'' grade:
** ''Homo erectus'' grade:
** ''Homo sapiens'' grade:
[[/folder]]

[[{{Gandhi}} Until he extends the circle of compassion to all living things, man will not himself find peace]]. That's why our direct ancestors are at the bottom of the Useful Notes. Technically [[PunyHumans a subset of Primates]], hominids is a group of animals somewhat controversial to talk about, for obvious ethical reasons. The group itself fluctuates in definition, going from all beings closer to us that to chimps, to all things closer to us that to baboons; the most widely accepted use includes the great apes; that's is, all beings closer to us that to gibbons, and that's the one to be used here. Anyway, this family split off from gibbons about 15 million years ago, and not long after, it split off in two main branches: The Asian branch, nowadays made up of the 2 species of orangutan; and the African branch, which includes gorillas, chimps and us. Focusing in that latter branch, the branch gorillas belong to splits off from the main branch 7 million years ago, and the chimp branch splits from the branch that would lead to us shortly after. That latter branch was subject to selective pressure due to having to adapt to the harshed savannah environment: The 2 modern chimp species split from each other at roughly the same time our branch split from Lucy (see below).

* Extinct Apes: Due to jungles not being good places for fossilization, not many species of extinct apes are known. The most notable one is the aforementioned ''[[http://en.wikipedia.org/wiki/Gigantopithecus Gigantopithecus]]'', a relative of the orangutan (that also exhibited gorilla-like characters), measuring up to 10 feet when standing upright. A species of extinct human, ''Homo erectus'', quite likely met this impressive creature, but that's the closest contact this animal had with humanity: competition with ''the giant panda'' drove it to extinction. Other extinct apes were once considered true human ancestors, or at least the common ancestors of apes and humans, but now are believed only distant relatives which shared some apparently human-like traits. ''[[http://en.wikipedia.org/wiki/Proconsul Proconsul]]'', ''[[http://en.wikipedia.org/wiki/Dryopithecus Dryopithecus]]'', and "Ramapithecus" (now ''[[http://en.wikipedia.org/wiki/Sivapithecus Sivapithecus]]'') are often mentioned in old textbook for this, but now their relevance is drastically fallen down.

* Stem-humans: An assortment of species that make up the classical Hominidae, but nowadays are generally agreed upon being "just" the subtribe Hominina. Their taxonomy is complex, but they can be, for convenience, divided in several grades:

** ''Australopithecus'' grade: Includes all hominines not included in the genus ''Homo'', the beings included in this grade are generally ape-like, being to the rest of apes what baboons are to other old-world monkeys. As we get torwards modern times, the species in this group become steadily more bipedal, adapt their feet to ground locomotion, and generally become more human-like. In the past, this used to be called the genus ''[[http://en.wikipedia.org/wiki/Australopithecus Australopithecus]]'', but taxonomical revisions have split off 2 other significant genera: The earlier ''[[http://en.wikipedia.org/wiki/Ardipithecus Ardipithecus]]'', and the robust, man sized ''[[http://en.wikipedia.org/wiki/Paranthropus Paranthropus]]''. Significant species of Australopithecus are ''A. afarensis'', best known for the specimen known as [[TheBeatles Lucy]]; and ''A. africanus'' (the first discovered, in 1925), likely an ancestor of the genus ''Homo''.

* [[http://en.wikipedia.org/wiki/Bat Prehistoric bats]]: Ok, we already know it, bats ''are not birds'' at all: but they fit better here for comparison. Just like birds, bats are a very poorly-known group in fossil record, both for the same reason: their skeleton is way too fragile to fossilize well. Despite this, awesomely well-preserved bat remains have been discovered in the most famous fossil deposit from Early Cenozoic: [[http://en.wikipedia.org/wiki/Messel_pit Messel Pit]], in Germany. This deposit has also many, many other early mammals: among them, the strange ''[[http://en.wikipedia.org/wiki/Leptictidium Leptictidium]]'' and the basal ungulate ''[[http://en.wikipedia.org/wiki/Propalaeotherium Propalaeotherium]]'' have been recently made famous by Walking With (even though the propalaeothere ''wasn't'' an early "horse" as said in the program). These and other mammals from this deposit are so well preserved that ''even their fur, feathers and stomach contents are known''. In short, we know'em almost like they were still-living animals. The very first bats have been discovered here, and show us all the traits associated with their modern relatives: fingered wings, large ears, and even structure for echolocating are known from these finds. This has lead scientist to make an intriguing hypothesis: perhaps were some sort of gliding proto-bats already living on Earth ''before'' pterosaurs and non-avian dinosaurs disappeared? This would also mean bat-winged critters ''did'' exist at the Age of Dinosaurs, thus making the "Mesozoic bat-winged fliers" thing partially TruthInTelevision.

** The most primitive Carnivores: True carnivore (members of the order Carnivora) appeared soon after the start of the Mammal Age, but remained small and unspecialized for a long amount of time. In the Eocene most of them were still weasel- or genet-like like ''[[http://en.wikipedia.org/wiki/Miacis Miacis]]'' , but they already showed the separation in the two main branches still-living today: the [[http://en.wikipedia.org/wiki/Caniformia dog branch]] (dogs, bears, raccoons, weasels and ''seals'') and the [[http://en.wikipedia.org/wiki/Feliformia cat branch]] (cats, genets, mongooses and ''hyenas''). All modern large-sized carnivores from bears to lions, from wolves to the walrus, descend from weasel- shaped critters. However, many small carnivores retain still today their ancient shape/size: because of their smallness, they are much less abundant in fossil record and their evolution is less understood.

** [[http://en.wikipedia.org/wiki/Creodontia Creodonts]]: Still before there were the Creodonts, which occupied the same ecological niche ruled by modern carnivores. Very diversified in shape and size, they were more primitive and arguably slower-moving than our meat-eating mammals: this has been often cited as the cause of their extincion, but scientists aren't sure of that. ''[[http://en.wikipedia.org/wiki/Hyaenodon Hyaenodon]]'' is regarded as the stock member of the group. The largest hyenodont species appears in Walking With as a formidable predator, but some hypothize it was mostly a scavenger.

** [[http://en.wikipedia.org/wiki/Evolution_of_cetaceans Early whales]]: ''All'' mammals were small and rodent-shaped at their beginnings. Then some became larger and more derived, but none with the same level as whales. The first whale ancestors appeared only 10 million years after the non-avian dinosaurs extinction. ''[[http://en.wikipedia.org/wiki/Ambulocetus Ambulocetus]]'' ("walking whale") is a good example of these: still four-limbed, it was already a good swimmer, but still resembled anything but a whale. Among the first fish-shaped cetaceans, ''[[http://en.wikipedia.org/wiki/Basilosaurus Basilosaurus]]'' reached the length of a modern baleen whale, but was much more slender, almost eel-like. When first discovered, its elongated shape was misidentified for a mosasaur-like marine reptile: hence its strange, dinosaurian-sounding name ("king lizard"). At that time, all whales still were active hunters, like modern killer- and sperm- whales; the first filter-feeders appeared much more recently, when our planet turned colder and immense shoals of krill began to float in polar waters. Other cetaceans, however, remained small and active predators, originating our dolphins. While cetaceans' natural history is now well-known, that of Pinnipeds (seals, sea-lions, walruses etc.) is still poorly-known: we are sure however, they descended from bear-like or otter-like ancestors, and are a more recent group than whales.

** The most primitive Ungulates: Once, "ungulates" (hoofed mammals) were believed a natural group of mammals; now ke know that several mammalian lineages reached the ungulate body-plan independently, and they do not make a real ensemble. Those which lived at the beginning of the Cenozoic (the Eocene epoch) were rather undifferentiated each other, and did not resemble most modern hoofed mammals. The two most famous are the small "ur-horse" ''Eohippus'' and the large ''Uintatherium'', both from the Eocene epoch: among the other eocenic "ungulates", ''[[http://en.wikipedia.org/wiki/Coryphodon Coryphodon]]'' and ''[[http://en.wikipedia.org/wiki/Phenacodus Phenacodus]]'' are frequently portrayed in books. ''Coryphodon'' was perhaps the first land mammal to exceed 1 ton in weight, and was rather similar to an hippo in shape. ''Phenacodus'' was not larger than a dog: with its several small hoofed digits like ''Eohippus'' and its long tail, it is often mentioned as the prototypical "basal ungulate". Just like ''Eohippus'' ''Phenacodus'' could have been a possible prey of the famous giant bird ''Gastornis''; while the massive ''Coryphodon'' and ''Uintatherium'' were too powerful to be threatened by any predator when adults, like modern rhinos and elephants.

''[[http://en.wikipedia.org/wiki/Arsinoitherium Arsinoitherium]]'': Sometimes misspelled "Arsinotherium", it was the most peculiar-looking among the aforementioned "pseudo-rhinos", with its huge, yet light-weighed, hollow "double-horn". The same size of modern rhinoceroses, this animal is often described as a "cross between a rhino and a hippo" because of its short legs and amphibian habits: it lived along the coasts bordering the shallow seas which covered modern-day Egypt, together with the ur-elephant ''Moeritherium''. It's worth noting that, unlike ''Moeritherium'', ''Arsinoitherium'' was ''not'' an elephant-predecessor as said in [[WalkingWithDinosaurs Sea Monsters]], and maybe didn't have that tapir-like nose seen in the program: this mammal is so strange that it is put in its own mammalian order, the Embrithopods, only distantly related with elephants.

* Other prehistoric hoofed mammals:

** ''[[http://en.wikipedia.org/wiki/Andrewsarchus Andrewsarchus]]'': One of the most enigmatic mammals, from the first part of the Cenozoic (the Eocene period). Only a skull is known, 3 ft long and vaguely wolf-like. Some argue it was the largest carnivorous land mammal ever, but we haven't any proof about that; it might be omnivorous instead. It was probably related with the much smaller [[http://en.wikipedia.org/wiki/Mesonychia Mesonychians]], the first meat-eating mammals which obtained a size larger than a house cat.

** [[http://en.wikipedia.org/wiki/Primate#Evolution Prehistoric primates]]: [[StockPhrase Man-Descended-From-Apes]]. ''[[RunningGag Man-Descended-From-Apes]]''. '''[[OverlyLongGag Man-Descended-From-Apes]]'''. '''''[[ThisIsSparta NO!!!]]''''' Man '''didn't descend''' from apes (that is, chimps, gorillas, orangutans, gibbons): we humans '''and''' chimps/gorillas/orangutans/gibbons all descend from a common ancestor, often called "ape" in popular media but no more closely related to chimps as it was to ourselves. Primate evolution is of particular interest for obvious reasons, but it'd be a too long argumentation here, and would go much beyond the aim of this trope: talking about the most interesting extinct critters. Indeed, most ancient non-hominid primates ''weren't'' particularly interesting compared to their modern descendents: their look was a lot monotonous, some resembled more a lemur, other a tarsier, other a monkey, and other modern apes. Most were small, although oversized baboons and overgrown lemurs are known in fossil record. But the main exception it this: ''[[http://en.wikipedia.org/wiki/Gigantopithecus Gigantopithecus]]''. Its name means "giant ape", and with reason. An orangutan relative, the shape of its teeth show us it was a plant-eater, but.... it was ''two times'' bigger than a modern silverback gorilla: a sort of middle-way between a Real-life gorilla and KingKong. Not only that, it was discovered near the Himalayas: could it be the mythical [[BigfootSasquatchAndYeti Yeti]]? If so, this would mean it could be ''still alive'' (don't be too excited: experts say it's ''highly improbable'' that such a large animal has remained unobserved for such a long amount of time...). Sadly, the only certain thing we know about it is just a lower fossil jaw.

* Prehistoric hoofed mammals:

** [[http://en.wikipedia.org/wiki/Rhinoceros Prehistoric rhinos]]: Modern rhinos are often referred as "prehistoric-looking" in media. Many classic prehistoric mammals were indeed rhino-like, but only few of them were ''true'' rhinoceroses. Among them, the most spectacular were the [[http://en.wikipedia.org/wiki/Coelodonta_antiquitatis Woolly Rhino]], the [[http://en.wikipedia.org/wiki/Elasmotherium_sibiricum Unicorn Rhino]], and above all, the [[http://en.wikipedia.org/wiki/Paraceratherium Indricothere]] (ironically, this one wasn't so rhino-looking). The Unicorn (''Elasmotherium sibiricum'') is often confused with the Woolly (''Coelodonta antiquitatis'') because of their similar appearence: however, the latter was not larger than modern white-rhinos and had ''two'' horns as well; the former was much larger (5 tons, like a modern bush elephant) and with one single horn... as long as a grown man, and put on the front rather than upon the nose: hence [[ExactlyWhatItSaysOnTheTin unicorn rhinoceros]]. We'll talk later about Indricotheres, they deserve their own entry.

** Prehistoric "pseudo-rhinos": As said above, not all rhinoceros-looking fossil mammals were real rhinos; but they'll probably get [[DidNotDoTheResearch identified as such in popular media]]. The most well-known are: ''[[http://en.wikipedia.org/wiki/Uintatherium Uintatherium]]''; ''[[http://en.wikipedia.org/wiki/Brontotherium Brontotherium]]''; and, a bit less familiar, ''Arsinoitherium'' (see further). The poor Uintathere is perhaps [[TheWoobie the most mistreated]] extinct mammal of all: expect somebody making a reference to its "monstrous" appearence or its "tiny" brain, just what happens to its Woobiesaurian equivalent, ''Stegosaurus''... Uintatheres were among the very first mammals to reach large size (about as a modern-day rhino), and their body-plan was ''very successful'' at the time: to the point they roamed northern continents in huge numbers for million years, before being substituted by the even larger Brontotheres (the cool-named "thunder beasts"). These had a more rhino-like look, having one single "horn" on their nose: ''Brontotherium'' 's prominence was forked and slingshot-like, while that of ''[[http://en.wikipedia.org/wiki/Embolotherium Embolotherium]]'' (the brontothere portrayed in [[WalkingWithDinosaurs Walking With Beasts) was shovel-like and not forked. Like uintathere, brontotheres too roamed northern plains in huge numbers before gone extinct, perhaps due to the diffusion of the very first grasslands, thus taking out their former food.

* [[http://en.wikipedia.org/wiki/Proboscidea Elephant relatives]]: There were A LOT of them in Prehistory: not so in {{Prehistoria}}. Don't expect to see any proboscidean in TV outside docus unless it's a [[StockDinosaurs Mammoth or an American Mastodon]], even though many of them were far cooler-looking than the latter. If you don't believe us, take a look on these: the shovel-jawed ''[[http://en.wikipedia.org/wiki/Platybelodon Platybelodon]]'' resembled a cross between an elephant and a hippo. The huge ''[[http://en.wikipedia.org/wiki/Deinotherium Deinotherium]]'' had two tusks ''on the lower jaw''. The ancestral ''[[http://en.wikipedia.org/wiki/Moeritherium Moeritherium]]'' (classicaly mentioned as "the first elephant") didn't resemble even an elephant: with its short trunk and short limbs, it was more similar to a modern tapir. But even more normally-looking proboscideans would appear cool-looking by our standards: see the [[http://en.wikipedia.org/wiki/Anancus European Mastodon]] and its sword-like tusks, just as as example. And oh, don't forget some island-dwellers which lived in the Ice Ages and almost managed to survive until human history: the oxymoronic [[http://en.wikipedia.org/wiki/Dwarf_elephant Dwarf Elephants]]. Yes, they were real, and some ''sheep-sized''.

* [[http://en.wikipedia.org/wiki/Felidae Extinct cats]]: There were dozens kinds of [[http://en.wikipedia.org/wiki/Saber-toothed_cat sabertoothed cats]] in RealLife. Some of them are nicknamed according to the form of their fangs: ''[[http://en.wikipedia.org/wiki/Homotherium Homotherium]]'' was the "Scimitar-tooth", ''[[http://en.wikipedia.org/wiki/Megantereon Megantereon]]'' the "dirktooth". While ''[[http://en.wikipedia.org/wiki/Machairodus Machairodus]]'' was the Euro-Afro-Asian sabertoothed equivalent of ''[[StockDinosaurs Smilodon]]'', not to mention [[http://en.wikipedia.org/wiki/Machairodontinae the actual prototype of the group]]; many European paleoartists have considered ''Machairodus'' as the ''real'' stock sabretooth instead of ''Smilodon''. But there were also more familiar-looking cats in the past. The most well-known are the [[http://en.wikipedia.org/wiki/Panthera_leo_atrox American Lion]] and its European cousin, the [[http://en.wikipedia.org/wiki/Panthera_leo_spelaea Cave Lion]], both simply larger, Ice Ages-related subspecies of the modern lion, well adapted to live in colder climates along with the mammoths. While ''[[http://en.wikipedia.org/wiki/Dinofelis Dinofelis]]'', despite resembling more a leopard, was actually a short-fanged saber-toothed cat. A curious thing is, even some prehistoric meat-eating mammals which were not cats at all, developed a bewildering "sabre-toothed" look ''before'' true cats appeared: two main examples are the pseudo-cat ''[[http://en.wikipedia.org/wiki/Eusmilus Eusmilus]]'' and the marsupial ''[[http://en.wikipedia.org/wiki/Thylacosmilus Thylacosmilus]]'', in particular the latter, being closer to ''kangaroos'' than to cats.

* [[http://en.wikipedia.org/wiki/http://en.wikipedia.org/wiki/Ground_sloth Giant Ground Sloths]]: Some of them were among the hugest land mammals ever lived, but many others weren't so giant-things (even though still large by human standards). Very strongly-built and weaponed with enormous claws, they were capable to walk around with their body upright, a bit like giant bears. Being members of the [[http://en.wikipedia.org/wiki/Xenarthra Xenarthran]] group, they were prevalently South American (some of them migrated to the North however) and had primitive teeth: nonetheless, they were so well-adapted to their environments that they flourished for almost the entire length of the Mammal-Ages: they got mysteriously extinct only few thousand years ago. The colossal ''[[http://en.wikipedia.org/wiki/Megatherium Megatherium]]'' is the prototypical giant ground sloth, was ''elephant-sized'', reached 5 m when fully erect, and its name means...well... [[ExactlyWhatItSaysOnTheTin big beast]].

* [[http://en.wikipedia.org/wiki/Glyptodont Glyptodonts]]: After Ankylosaurs went extinct, evolution decided to create their mammalian equivalents: the glyptodonts. They were Xenarthrans as well, but related to armadillos rather than to sloths. Lived in South America for dozen million years, before going extinct only few thousands years ago: in short, they had the same identical history of their cousins, the giant sloths. Both groups were veggie-eaters (despite giant sloth might be at least partially scavengers), and when adult, they feared no predators except humans. There is a secret behind their success: their backbone. It was far, far stronger that every other mammal, thus permitting them carrying such heavy bodies around withouth suffering back pain. ''[[http://en.wikipedia.org/wiki/Glyptodon Glyptodon]]'' is the most well-known glyptodont, but it's also worth of mention ''[[http://en.wikipedia.org/wiki/Doedicurus Doedicurus]]'': with its mace-like tail, it was the most ''Ankylosaurus''-like of them all.

* Extinct hoofed mammals:

** Prehistoric "pseudo-rhinos": As said above, not all rhinoceros-looking fossil mammals were real rhinos; but they'll probably get [[DidNotDoTheResearch identified as such in popular media]]. The most well-known are: ''[[http://en.wikipedia.org/wiki/Uintatherium Uintatherium]]''; ''[[http://en.wikipedia.org/wiki/Brontotherium Brontotherium]]''; and, a bit less familiar, ''[[http://en.wikipedia.org/wiki/Arsinoitherium Arsinoitherium]]''. The poor Uintathere is perhaps [[TheWoobie the most mistreated]] extinct mammal of all: expect somebody making a reference to its "monstrous" appearence or its "tiny" brain, just what happens to its Woobiesaurian equivalent, ''Stegosaurus''... Uintatheres were among the very first mammals to reach large size (about as a modern-day rhino), and their body-plan was ''very successful'' at the time: to the point they roamed northern continents in huge numbers for million years, before being substituted by the even larger Brontotheres (the cool-named "thunder beasts"). These had a more rhino-like look, having one single "horn" on their nose: ''Brontotherium'' 's prominence was forked and slingshot-like. They too roamed northern plains in huge numbers before gone extinct, perhaps due to the diffusion of the very first grasslands, thus taking out their former food. ''Arsinoitherium'' was the most peculiar-looking "pseudo-rhino", with its huge "double-horn".

* Extinct carnivorous mammals:

* The MirrorUniverse birds: The most successful Late Cretaceous birds were the [[http://en.wikipedia.org/wiki/Enantiorns Enantiorns]], whose name means "mirror birds". Why? Because of some skeletal features which appear specular compared to modern fliers. They were a sort of middle-ways between the aforementioned Early Cretaceous birds and modern feathered guys, and were very diversified among each other. The "omnipresent chorus" of birds mentioned in the last WalkingWithDinosaurs episode was, arguably, made by enantiorns. They went extinct along with non-avian dinos only after the comet/asteroid.