Distinguishing Characteristics: Rhinoceros-like trunk; two conical horns on head; quadrupedal posture; primitive teeth Although it wasn't directly ancestral to the modern rhinoceros, Arsinoitherium (the name refers to the mythical Egyptian Queen Absence) cut a very rhino-like profile, with its stumpy legs, squat trunk and herbivorous diet.
However, what really set this prehistoric mammal apart from the other megafauna of the Eocene epoch were the two large, conical, pointed horns jutting out from the middle of its forehead, which were likely a sexually selected characteristic rather than anything meant to intimidate predators (meaning that males with bigger, pointier horns had a better chance of pairing up with females during mating season). Arsinoitherium was also equipped with 44 flat, stumpy teeth in its jaws, which were well-adapted to chewing the extra-tough plants of its Egyptian habitat circa 30 million years ago.
During the Miocene epoch, South America was cut off from the rest of the world's continents, resulting in the evolution of a bizarre array of mammalian megafauna. Astrapotherium was a typical example: this hooked ungulate (a distant relative of horses) looked like a cross between an elephant, a tapir, and a rhinoceros, with a short, prehensile trunk and powerful tusks.
The nostrils of Astrapotherium were also set unusually high, a hint that this prehistoric herbivore may have pursued a partly amphibious lifestyle, like a modern hippopotamus. As you might have guessed, this ancestor of modern cattle figured on the dinner menu of early humans, who helped drive the Aurochs into extinction.
The Cave Bear (URSS spellers) was one of the most common megafauna mammals of Pleistocene Europe. You might think it strange that a creature as ordinary and inoffensive as a prehistoric goat would make headlines around the world, but Myotragus merits the attention: according to one analysis, this smallish “Cave Goat” adapted to the sparse food of its island habitat by evolving a cold-blooded metabolism, similar to that of reptiles.
(In fact, the authors of the paper compared fossilized Myotragus bones to those of contemporary reptiles, and found similar growth patterns.) As you might expect, not everyone subscribes to the theory that Myotragus had a reptile-like metabolism (which would make it the first mammal in history to have ever evolved this bizarre trait).
More likely, this was simply a slow, stubby, ponderous, small-brained Pleistocene herbivore that had the luxury of not having to defend itself against natural predators. Simple: the “chalice” part of its name refers to Chalicotherium's pebble-like teeth, which it used to grind down tough vegetation.
Chamitataxus runs counter to the general rule that every modern mammal had a plus-sized ancestor lurking millions of years back in its family tree. Somewhat disappointingly, this badger of the Miocene epoch was about the same size as its descendants of today, and it seems to have behaved in much the same way, locating small animals with its excellent smell and hearing and killing them with a quick bite to the neck.
Perhaps the small proportions of Chamitataxus can be explained by the fact that it coexisted with Tax idea, the American Badger, which still annoys homeowners in the present day. Coryphodon. Heinrich Harder Perhaps because efficient predators were in short supply during the early Eocene epoch, Coryphodon was a slow, lumbering beast, with an tiny brain that beckons comparison with those of its dinosaur predecessors.
The Miocene pig Daemon (formerly known as Dinosaur) was roughly the size and weight of a modern rhinoceros, with a broad, flat, warthog-like face complete with “warts” (actually fleshy wattles supported by bone). About the size of a modern tabby cat, Deinogalerix probably made its living by feeding on insects and the carcasses of dead animals.
Although it was directly ancestral to modern hedgehogs, for all intents and purposes Deinogalerix looked like a giant rat, with its naked tail and feet, narrow snout, and (one imagines) overall peskiness. If you happened across Desmostylus 10 or 15 million years ago, you might be forgiven for mistaking it for a direct ancestor of either hippopotamuses or elephants: this megafauna mammal had a thick, hippo-like body, and the shovel-shaped tusks jutting out of its lower jaw were reminiscent of prehistoric proboscis like Megalodon.
It was once believed that Desmostylus and its equally strange relatives subsisted on seaweed, but a more likely diet now seems to have been the wide range of marine vegetation surrounding the northern Pacific basin. Epicurus. Wikimedia Commons This slow-moving prehistoric armadillo Epicurus was not only covered by a large, domed, armored shell, but it possessed a clubbed, spiked tail similar to those of the ankylose and stegosauri dinosaurs that preceded it by tens of millions of years.
Of all the brontosaurs (which also included Brontotherium), Embolotherium had the most distinctive “horn,” which actually looked more like a broad, flat shield sticking up from the end of its snout. As with all such animal accouterments, this odd structure may have been used for display and/or to produce sounds, and it was doubtless a sexually selected characteristic as well (meaning males with more prominent nose ornaments mated with more females).
For all intents and purposes, Eobasileus can be considered a slightly smaller version of the more famous Uintatherium, yet another prehistoric megafauna mammal that roamed the plains of Eocene North America. Like Uintatherium, Eobasileus cut a vaguely rhino-shaped profile and had an exceptionally knobby head sporting three matched pairs of blunt horns as well as short tusks.
It's still unclear how these “untethered” of 40 million years ago were related to modern herbivores; all we can say for sure, and leave it at that, is that they were very large ungulates (hooked mammals). Judging by its long and arms and huge, clawed hands, Eremotherium made its living by mauling and eating trees; it lasted well into the last Ice Age, only to be hunted to extinction by the early human settlers of North and South America.
Sometimes, all it takes to propel an obscure prehistoric mammal onto the evening news is the discovery of a new, almost intact specimen. The central Asian Fernando has actually been known to paleontologists for over 30 years, but the “type fossil” was in such bad shape that few took notice.
Now, the discovery of new Fernando specimen in Mongolia has cast new light on this strange mammal, which lived in the late Paleocene epoch, less than 10 million years after the dinosaurs went extinct. Long story short, Fernando was a small, digging mammal that seems to have been ancestral to modern pangolins (which it probably resembled).
In most respects, Eucladoceros wasn't much different from modern deer and moose, to which this megafauna mammal was directly ancestral. Oddly enough, the antlers of Eucladoceros don't seem to have grown in any regular pattern, possessing a fractal, branching shape that must have been an impressive sight during mating season.
In an odd reversal of the usual pattern with megafauna mammals, Eurotamandua wasn't significantly bigger than modern anteaters; in fact, this three-foot-long creature was considerably smaller than the modern Giant Anteater, which can attain lengths of over six feet. However, there's no mistaking Eurotamandua's diet, which can be inferred from its long, tubular snout, powerful, clawed front limbs (which were used for digging up anthills), and muscular, gripping tail (which held it in place as it settled in for a nice, long meal).
What's less clear is whether Eurotamandua was a true anteater, or a prehistoric mammal more closely related to modern pangolins; paleontologists are still debating the issue. If it did, no evidence has been preserved, though some enthusiasts point to a four-foot-high dam in Ohio (which may well have been made by another animal, or a natural process).
Giant Hyena (Pachycrocuta). Wikimedia Commons Pachycrocuta, also known as the Giant Hyena, followed a recognizably hyena-like lifestyle, stealing freshly killed prey from its fellow predators of Pleistocene Africa and Eurasia and occasionally even hunting for its own food. Yet another of the giant megafauna mammals that prowled the forests and plains of Pleistocene North and South America, Glossotherium was slightly smaller than the truly gigantic Regathering but slightly bigger than its fellow ground sloth Megaton (which is famous for having been discovered by Thomas Jefferson).
Giant mammals always have diminutive ancestors lurking somewhere far down on the family tree, a rule that applies to horses, elephants and, yes, sloths. Everyone knows about the Giant Sloth, Regathering, but you may not have been aware that this multi-ton beast was related to the sheep-sized Catalogs, which lived tens of millions of years earlier, during the Miocene epoch.
Oddly enough, considering its descendants, this megafauna mammal was named after an entirely different (and even more obscure) modern creature, the hoax. Although Hydrocodone looked a lot like a prehistoric horse, an analysis of this creature's legs shows that it wasn't a particularly fast runner, and therefore probably spent most of its time in sheltered woodlands rather than open plains (where it would have been more susceptible to predation).
(Oddly enough, Icaronycteris existed in the same time and place as another prehistoric bat that lacked the ability to echo locate, Onychonycteris.) Indricotherium. Indricotherium (Same er Prehistoric) A gigantic ancestor of the modern rhinoceros, the 15-to-20-ton Indricotherium possessed a fairly long neck (though nothing approaching what you'd see on a sauropod dinosaur), as well as surprisingly thin legs capped by three-toed feet.
It's a good thing you didn't live in South America a few million years ago, when the one-ton rodent Josephoartigasia prowled the continent's swamps and estuaries. Since it's represented in the fossil record by a single skull, there's still much that paleontologists don't know about the life of Josephoartigasia; we can only guess at its diet, which probably consisted of soft plants (and possibly fruits), and it likely wielded its giant front teeth either to compete for females or to deter predators (or both).
Now, further study of some Agriarctos-like fossils unearthed in Spain has led experts to designate an even earlier genus of Panda ancestor, Kretzoiarctos (after paleontologist Miles Breton). Kretzoiarctos lived about a million years before Agriarctos, and it enjoyed an omnivorous diet, feasting on the tough vegetables (and occasionally small mammals) of its western European habitat.
Leptictidium. Wikimedia Commons When various fossils of Leptictidium were unearthed in Germany a few decades ago, paleontologists were faced with a conundrum: this small, shrew-like mammal appeared to be completely bipedal. As common as it was on the North American plains tens of million of years ago, Leptomeryx would get more press if it were easier to classify.
One interesting thing about Leptomeryx is that the later species of this megafauna mammal had a more elaborate tooth structure, which was probably an adaptation to their increasingly parched ecosystem (which encouraged the growth of tougher-to-digest plants). Macrauchenia. Sergio Perez The long trunk of Macrauchenia hints that this megafauna mammal fed on the low-lying leaves of trees, but its horse-like teeth point to a diet of grass.
Megaton. American Museum of Natural History Besides its one-ton bulk, Megaton, also known as the Giant Ground Sloth, was distinguished by its significantly longer front than hind legs, a clue that it used its long front claws to rope in copious amounts of vegetation from trees. Regathering (Giant Sloth). Paris Natural History Museum Regathering, aka the Giant Sloth, is an interesting case study in convergent evolution: if you ignore its thick coat of fur, this mammal was anatomically very similar to the tall, pot-bellied, razor-clawed breed of dinosaurs known as therizinosaurs.
You can get the true measure of Megistotherium by learning its last, i.e., species name: “osteoblasts,” Greek for “bone-crushing.” This was the biggest of all the credits, the carnivorous mammals that preceded modern wolves, cats and hyenas, weighing close to a ton and with a long, massive, powerfully jawed head.
As big as it was, though, it's possible that Megistotherium was unusually slow and clumsy, a hint that it may have scavenged already-dead carcasses (like a hyena) rather than actively hunting down prey (like a wolf). The only megafauna carnivore to rival it in size was Andrewsarchus, which may or may not have been substantially bigger, depending on whose reconstruction you believe.
As prehistoric rhinoceroses go, Fencers didn't cut an especially impressive profile, especially compared to such gigantic, weirdly proportioned members of the breed as the 20-ton Indricotherium (which appeared on the scene much later). The discovery of numerous Fencers bones in various places in the United States (including Nebraska, Florida, California and New Jersey) is evidence that this megafauna mammal roamed the American plains in wide-ranging herds.
Merycoidodon is one of those prehistoric herbivores that's hard to get a good grasp on since it doesn't have any analogous counterparts alive today. This megafauna mammal is technically classified as a “blood,” a subfamily of artiodactyls (even-toed ungulates) related to both pigs and cattle, and today represented only by modern camels.
If you saw a picture of Mes onyx, you might be forgiven for thinking that it was ancestral to modern wolves and dogs: this Eocene mammal had a slender, quadrupedal build, with canine-like paws and a narrow snout (probably tipped by a wet, black nose). However, Mes onyx appeared way too early in evolutionary history to be directly related to dogs; rather, paleontologists speculate that it may have lain near the root of the evolutionary branch that led to whales (note its similarity to the land-dwelling whale ancestor Pakicetus).
Mes onyx also played an important part in the discovery of another, bigger Eocene carnivore, the gigantic Andrewsarchus ; this central Asian megafauna predator was reconstructed from a single, partial skull based on its presumed relationship to Mes onyx. If you've never quite understood the difference between rhinoceroses and hippopotamuses, you're bound to be confused by Metamynodon, which was technically a prehistoric rhinoceros but looked much, much more like an ancient hippo.
The lower jaw of Metridiochoerus. Wikimedia Commons Name: Metridiochoerus (Greek for “frightful pig”); pronounced meh-TRID-ee-oh-CARE-us. Although its name is Greek for “frightful pig,” and it's sometimes called the Giant Warthog, Metridiocheorus was a true runt among the multi-ton mammalian megafauna of Pleistocene Africa.
The fact is that, at 200 pounds or so, this prehistoric porker was only slightly bigger than the still-extant African Warthog, albeit equipped with more dangerous-looking tusks. Moro pus. National Museum of Natural History Name: Moro pus (Greek for “stupid foot”); pronounced MORE-oh-pus.
Although the name Moro pus (“stupid foot”) is striking in translation, this prehistoric mammal might have been better served by its original moniker, Macrotherium (“giant beast”)--which would at least drive home its relationship to the other “thorium” megafauna of the Miocene epoch, especially its close relative Chalicotherium. Essentially, Moro opus was a slightly bigger version of Chalicotherium, both of these mammals characterized by their long front legs, horse-like snouts and herbivorous diets.
Compared to its fellow giant sloths like the three-ton Regathering and Eremotherium, Million was the runt of the litter, “only” measuring about 10 feet from head to tail and weighing about 500 pounds. Interestingly, the scattered pelt and dung fragments of Million have been so well-preserved that paleontologists once believed this prehistoric sloth never went extinct and was still living in the wilds of South America (a premise that was soon proven incorrect).
Like its closest relatives, Neocon is technically categorized as a “notoungulate,” a distinctive breed of hooked mammals that have left no direct living descendants. Onychonycteris, the “clawed bat,” is a case study in the unexpected twists and turns of evolution: this prehistoric bat existed alongside Icaronycteris, another flying mammal of early Eocene North America, yet it differed from its winged relative in several important respects.
At some point during the early Eocene epoch--and probably well before, as far back as the late Cretaceous period--the first mouse-sized mammals evolved the ability to fly, inaugurating the evolutionary line leading to modern bats. The tiny (no more than three inches long and one ounce) Palaeochiropteryx already possessed the beginnings of the bat-like inner-ear structure necessary for echolocation, and its stubby wings would have allowed it to flutter at low altitudes over the forest floors of Western Europe.
Not surprisingly, Palaeochiropteryx seems to have been closely related to its North American contemporary, the early Eocene Icaronycteris. Disappointingly, the ancient rabbit Palaeolagus wasn't monster-sized, like so many prehistoric ancestors of existing mammals (for sake of contrast, witness the Giant Beaver, Asteroids, which weighed as much as a full-grown human).
Very few complete fossils of Palaeolagus have been found; as you might imagine, this tiny mammal was so often preyed on by Oligocene carnivores that it has survived down to the present day only in bits and pieces. Named by a bemused paleontologist after its odd mix of features, Paleoparadoxia (Greek for “ancient puzzle”) had a large, horse-like head, a squat, walrus-like trunk, and splayed, inward-curving legs more reminiscent of a prehistoric crocodile than a megafauna mammal.
This central African mammal looked like a gigantic bull, the most notable difference being the huge (about six feet long from base to tip), paired horns on top of its massive head. As you might expect for a tasty bit of mammalian megafauna that shared the African plains with early humans, specimens of Pelvis have been found bearing the imprints of primitive stone weapons.
One of the more comical-looking megafauna mammals of prehistoric times, Peltephilus looked like a giant badger pretending to be a cross between an Ankylosaurus and a rhinoceros. This five-foot-long armadillo sported some impressive-looking, flexible armor (which would have allowed it to curl up into a big ball when threatened), as well as two largish horns on its snout, which were undoubtedly a sexually selected characteristic (i.e., Peltephilus males with bigger horns got to mate with more females).
As big as it was, though, Peltephilus was no match for giant armadillo descendants like Glyptodon and Epicurus that succeeded it by a few million years. Phenacodus was one of the “plain vanilla” mammals of the early Eocene epoch, a medium-sized, vaguely deer- or horse-like herbivore that evolved a mere 10 million years after the dinosaurs had gone extinct.
Peccaries are vicious, omnivorous, pig-like herd animals that live mostly in South and Central America; Platoons was one of their oldest ancestors, a relatively long-legged member of the breed that may occasionally have ventured beyond the forests of its North American habitat and onto the open plains. Unlike modern peccaries, Platoons seems to have been a strict herbivore, using its dangerous-looking tusks only to intimidate predators or other members of the herd (and possibly to help it dig up tasty vegetables).
This megafauna mammal also had an unusually advanced digestive system similar to that of ruminants (i.e., cows, goats, and sheep). Named in the middle 19th century by the famous paleontologist Joseph Lady, Poebrotherium is one of the earliest camels yet identified in the fossil record, a long-legged, sheep-sized herbivore with a distinctly llama-like head.
At this stage in camel evolution, about 35 to 25 million years ago, characteristic features like fatty humps and knobby legs had yet to appear; in fact, if you didn't know Poebrotherium was a camel, you might assume this megafauna mammal was a prehistoric deer. When its fossils were first discovered, way back in 1833, no one was quite sure what to make of Potamotherium, though the preponderance of the evidence pointed to its being a prehistoric weasel (a logical conclusion, given this megafauna mammal's sleek, weasel-like body).
However, further studies have relocated Potamotherium on the evolutionary tree as a distant ancestor of modern pinnies, a family of marine mammals that includes seals and walruses. If you came across Producers and its “protoceratid” relatives 20 million years ago, you might be forgiven for thinking that these megafauna mammals were prehistoric deer.
Like so many ancient artiodactyls (even-toed ungulates), though, Producers and its ilk have proven difficult to classify; their closest living relatives are most likely camels rather than elks or pronghorns. Whatever its classification, Producers was one of the earliest members of this distinctive group of megafauna mammals, with four-toed feet (later protoceratids only had two toes) and, on the males, three sets of paired, stubby horns running from the top of the head down to the snout.
Pyrotherium was actually a medium-sized, vaguely elephant-like megafauna mammal that prowled the woodlands of South America about 30 million years ago, its tusks and prehensile snout pointing to a classic pattern of convergent evolution (in other words, Pyrotherium lived like an elephant, so it evolved to look like an elephant as well). This megafauna mammal possessed a relatively short neck and a cow-like muzzle, indicating that it grazed on the low-lying grass of late Miocene Africa and Eurasia rather than nibbling the high leaves of trees.
In a typical example of convergent evolution, Saskatoon looked a lot like a modern grizzly bear (if you make allowances for its long, fluffy tail), and it probably lived a lot like a grizzly bear as well, feeding opportunistically on fish, plants and other animals. Also, Saskatoon's large, heavy teeth were especially well adapted to cracking bones, either of live prey or carcasses.
One thing that set Sin onyx apart from the true prehistoric ancestors of dogs and wolves (which arrived on the scene millions of years later) is that it possessed small hooves on its feet, and was ancestral not to modern mammalian carnivores, but to even-toed ungulates like deer, sheep, and giraffes. Until recently, paleontologists even speculated that Sin onyx may even have been ancestral to the first prehistoric whales (and thus a close relative of early cetacean genera like Pakicetus and Ambulocetus), though it now seems that mesonychids were distant cousins to the whales, a few times removed, rather than their direct progenitors.
Sivatherium. Heinrich Harder Like many megafauna mammals of the Pleistocene epoch, Sivatherium was hunted to extinction by early humans; crude pictures of this prehistoric giraffe have been found preserved on rocks in the Saharan Desert, dating to tens of thousands of years ago. Stag Moose. Wikimedia Commons Like other Pleistocene mammals of North America, the Stag Moose may have been hunted to extinction by early humans, but it also may have succumbed to climate change at the end of the last Ice Age and the loss of its natural pasture.
In 1741, a population of a thousand giant sea cows was studied by the early naturalist Georg Wilhelm Seller, who remarked on this megafauna mammal's tame disposition, undersized head on an oversized body, and exclusive diet of seaweed. The skull of Stephanorhinus. Wikimedia Commons The remains of the prehistoric rhinoceros Stephanorhinus have been found in a startling number of countries, ranging from France, Spain, Russia, Greece, China, and Korea to (possibly) Israel and Lebanon.
Although it looked (and probably behaved) like a modern deer, Syndyoceras was only a remote relative: true, this megafauna mammal was an artiodactyl (even-toed ungulate), but it belonged to an obscure sub-family of this breed, the protoceratids, the only living descendants of which are camels. Synthetoceras was the latest, and largest, member of the obscure family of artiodactyls (even-toed ungulates) known as protoceratids; it lived a few million years after Producers and Syndyoceras and was at least double their size.
Like modern deer, Synthetoceras seems to have lived in large herds, where the males maintained dominance (and competed for females) according to the size and impressiveness of their horns. Telenovelas was technically a prehistoric rhinoceros, albeit one with distinctively hippo-like characteristics: its long, squat body and stumpy legs were well-adapted to a partially aquatic lifestyle, and it even had hippo-like teeth.
However, the small, almost insignificant horn on the front of Telenovelas' snout points to its true rhinoceros roots. But the Pliocene epoch also witnessed its share of weirdly adapted, “one-off” sloths, the prime example being Thalassocnus, which dived for food off the coast of northwestern South America (the interior of that part of the continent consisting mostly of desert).
The name Titanotylopus has precedence among paleontologists, but the now-discarded Gigantocamelus makes more sense: essentially, Titanotylopus was the “dino-camel” of the Pleistocene epoch, and was one of the biggest megafauna mammals of North America and Eurasia (yes, camels were once indigenous to North America!) Befitting the “Dino” part of its nickname, Titanotylopus had an tiny brain for its size, and its upper canines were larger than those of modern camels (but still not anything approaching saber-tooth status).
This one-ton mammal also had broad, flat feet well-adapted to walking on rough terrain, hence the translation of its Greek name, “giant knob bed foot.” Thanks to the wonders of convergent evolution, this herbivore evolved to look very much like a modern rhinoceros, with stubby legs, a short neck, and teeth well adapted to eating tough grass (it may also have been equipped with a short, elephant-like proboscis at the end of its snout).
Many London remains have been found in proximity to primitive arrowheads, a sure sign that this slow, lumbering beast was hunted to extinction by early humans. Some prehistoric rhinoceroses looked more like their modern counterparts than others: whereas you might have a hard time locating Indricotherium or Metamynodon on the rhino family tree, the same difficulty doesn't apply to Triennial, which (if you glanced at this megafauna mammal without your glasses on) would have cut a very rhino-like profile.
The difference is that Triennial had five toes on its feet, rather than three as in most other prehistoric rhinos, and it lacked even the barest hint of a nasal horn. Triennial lived in North America and Western Europe, the ancestral home of rhinos before they relocated farther east after the Miocene epoch.
Uintatherium didn't excel in the intelligence department, with its tiny brain compared to the rest of its bulky body. How this megafauna mammal managed to survive for so long, until it vanished without a trace about 40 million years ago, is a bit of a mystery.
The Woolly Rhino. Mauricio Anton Coelodonta, aka the Woolly Rhino, was very similar to modern rhinoceroses--that is, if you overlook its shaggy coat of fur and its odd, paired horns, including a big, upward-curving one on the tip of its snout and a smaller pair set further up, nearer its eyes. The species was named from Rock Creek, Texas, United States, where multiple skeletons were recovered.
Until the end of the last ice age, American cheetahs, enormous armadillo like creatures and giant sloths called North America home. Both research and the debate surrounding the reasons for the extinction of these animals will undeniably continue.
Here's a look at 10 extinct animals from the last North American ice age, and what scientists know about their lives. (Image credit: Copyright AMH D. Finn in)European settlers introduced horses when they landed in the New World.
After reaching North America about 2 million years ago, Glyptodon prospered in what is now coastal Texas and Florida, he said. (Image credit: Copyright AMH D. Finn in)Mastodons (Mammal) entered North America about 15 million years ago, traveling over the Bering Strait land bridge, long before their relative, the mammoth, according to the Yukon Bering Interpretive Center in Canada.
Mammoths had fatty humps on their backs that likely provided them with nutrients and warmth during icy periods, according to a February 2013 piece in Live Science. (Image credit: Courtesy of the Natural History Museum of Los Angeles County)Despite its name, this enormous bear didn't actually have a short face.
“It had very long forelimbs and hind limbs,” which likely helped it run at high speeds, he said. “One idea is that short-faced bears ran down their prey like cats do, but for a whole number of reasons, that is no longer the preferred argument,” he said.
Now, researchers are looking for clues that may reveal whether the carnivore was a hunter, a scavenger or both, Machete said. (Image credit: Courtesy of the Natural History Museum of Los Angeles County)Dire-wolf bones are plentiful in California's La Area Tar Pits and Wyoming's Natural Trap Cave.
However, the dire wolf had shorter limbs than C. lupus, suggesting it wouldn't have won any races against its younger relative, the museum reported. However, the American cheetah probably wasn't as fast: It had slightly shorter legs, which likely made it a better climber than a runner, according to the zoo.
In fact, ground-sloth fossils indicate that these animals began living in South America about 35 million years ago, according to the zoo. Researchers uncovered a 4.8-million-year-old Megaton fossil in Mexico, and later, specimens were found in present-day America, especially in areas that used to have forests, lakes and rivers.
During warmer periods, called interglacials, Megaton made it as far north as the Yukon and Alaska, Machete said. Like Megaton, the giant beaver ventured into Alaska and the Yukon during the interglacial periods, but retreated south when temperatures dropped, Machete said.
Interestingly, modern beaver remains are found in the same deposits as those of their ancient relatives, suggesting they had similar lifestyles, Machete said. However, Camelots is more closely related to llamas than to today's camels, the zoo reported.
Fossils show that the came lid family arose in North America during the Eocene period, about 45 million years ago, the zoo said. It lived in open spaces and dry areas, but it's unclear whether it could conserve water as modern camels do, Machete said.
We’ve all heard stories from the age of the dinosaurs, when giant creatures the size of buses or even buildings roamed the land and the oceans, but their disappearance didn’t mean the end of the giants: In fact, megafauna was predominant in every continent on Earth, through multiple glaciations and climate change periods, until about 50,000 years ago during the Late Pleistocene. Our increasing hunting and habitat pressure lead to a great decrease in the numbers and distribution of megafauna, followed by subsequent extinctions.
The biggest of all are the mega herbivores (>1000 kg), such as elephants or hippos, true ecological engineers capable of altering vegetation on a landscape scale. Their effects on ecosystems and vegetation can be amplified when they aggregate into groups, which also decreases the risk of predation and improves their survival rates.
These early extinctions, such as the saber tooth cat, closely match the timeline of our ancestor Homo erectus spreading across the continent and entering the carnivore niche space. In other regions of the world, such as Australia and the Americas, the timing of megafaunal loss coincides almost perfectly with the global expansion of Homo sapiens.
The arrival of humans often left no time for megafauna to adapt: Archaeologists now estimate that it only took about a hundred years for the giant MOA birds to go extinct after the Maori landed on New Zealand. The main reasons humans were able to make such an impact on megafauna population in so little time are that their omnivorous and generalist diet allowed them to maintain predation pressure even when prey abundance was low, and that large animals tend to breed less and have fewer offspring than smaller ones.
Although some other factors, such as climate change, may have acted in conjunction with human pressures in some cases, no close links have been found. Recreation of a scene in late Pleistocene northern Spain, by Mauricio Anton The last glacial period, commonly referred to as the 'Ice Age', spanned 125,000 to 14,500 years ago and was the most recent glacial period within the current ice age which occurred during the final years of the Pleistocene epoch.
The Ice Age reached its peak during the last glacial maximum, when ice sheets commenced advancing from 33,000 years BP and reached their maximum positions 26,500 years BP. Glaciation commenced in the Northern Hemisphere approximately 19,000 years BP, and in Antarctica approximately 14,500 years BP which is consistent with evidence that this was the primary source for an abrupt rise in the sea level 14,500 years ago.
A vast mammoth steppe stretched from the Iberian Peninsula across Eurasia and over the Bering land bridge into Alaska and the Yukon where it was stopped by the Wisconsin glaciation. This land bridge existed because more of the planet's water was locked up in glaciation than now and therefore the sea levels were lower.
When the sea levels began to rise this bridge was inundated around 11,000 years BP. During the last glacial maximum, the continent of Europe was much colder and drier than it is today, with polar desert in the north and the remainder steppe or tundra.
Forest and woodland was almost non-existent, except for isolated pockets in the mountain ranges of Southern Europe. The fossil evidence from many continents points to the extinction mainly of large animals at or near the end of the last glaciation.
Scientists frequently define megafauna as the set of animals with an adult body weight of over 44 kg (or 97 lbs). Across Eurasia, the straight-tusked elephant became extinct between 100,000–50,000 years BP.
The cave bear (URSS spellers), interglacial rhinoceros (Stephanorhinus), heavy-bodied Asian antelope (Spirochetes), and the Eurasian hippopotamuses died out between 50,000-16,000 years BP. The woolly rhinoceros and mammoths died out between 16,000-11,500 years BP.
The giant deer died out after 11,500 BP with the last pocket having survived until about 7,700 years BP in western Siberia. A pocket of mammoths survived on Wrangell Island until 4,500 years BP.
Among the top predators, the sabre-toothed cat (Homotherium) died out 28,000 years BP, the cave lion 11,900 years BP, and the leopard in Europe died out 27,000 years BP. The Late Pleistocene was characterized by a series of severe and rapid climate oscillations with regional temperature changes of up to 16 °C, which has been correlated with megafaunal extinctions.
There is no evidence of megafaunal extinctions at the height of the LGM, indicating that increasing cold and glaciation were not factors. Multiple events appear to also involve the rapid replacement of one species by one within the same genus, or one population by another within the same species, across a broad area.
The ancestors of modern humans first appeared in East Africa 195,000 years ago. Some migrated out of Africa 60,000 years ago, with one group reaching Central Asia 50,000 years ago.
From there they reached Europe, with human remains dated to 43,000-45,000 years BP discovered in Italy, Britain, and in the European Russian Arctic dated to 40,000 years ago. Another group left Central Asia and reached the Yang River, Siberia, well above the Arctic circle, 27,000 years ago.
Remains of mammoth that had been hunted by humans 45,000 GBP have been found at Yenisei Bay in the central Siberian Arctic. Modern humans then made their way across the Bering land bridge and into North America between 20,000-11,000 years ago, after the Wisconsin glaciation had retreated but before the Bering land bridge became inundated by the sea.
In the Fertile crescent the first agriculture was developing 11,500 years ago. Four theories have been advanced as likely causes of these extinctions: hunting by the spreading humans (or overkill hypothesis, initially developed by scientist Paul S. Martin), the change in climate at the end of the last glacial period, disease, and an impact from an asteroid or comet.
These factors are not necessarily exclusive: any or all may have combined to cause the extinctions. Although not mutually exclusive, which factor was more important still remains contested.
Where humans appeared on the scene, megafauna went extinct; but at the same time, the climate was also warming. Large body size is an adaptation to colder climes, so a warming climate would have provided a stressor for these large animals; however, many faunae simply evolved a smaller body size over time.
There is overwhelming archaeological evidence suggesting humans did indeed hunt some or many of the now extinct species, such as the mammoth in North America; on the other hand, there is not much evidence for this in Australia for most of the megafauna that went extinct there, aside from a large bird. A 2017 study in Nature Communications asserts that humans were the primary driver of the extinction of Australian megafauna.
One paper arguing genetic evidence shows there were many species of megafauna that went extinct “invisibly” argues that this means climate change was primarily responsible. Regardless, evidence suggests that humans were a major factor responsible for these extinctions.
During the American megafaunal extinction event around 12,700 years ago, 90 genera of mammals weighing over 44 kilograms became extinct. The Late Pleistocene fauna in North America included giant sloths, short-faced bears, several species of tapirs, peccaries (including the long-nosed and flat-headed peccaries), the American lion, giant tortoises, Miracinonyx (“American cheetahs”, not true cheetahs), the saber-toothed cat Million and the scimitar-toothed cat Homotherium, dire wolves, siege, came lids such as two species of now-extinct llamas and Camelots, at least two species of bison, the stag-moose, the shrub-ox and Harlan's muskox, 14 species of pronghorn (of which 13 are now extinct), horses, mammoths and mastodons, the beautiful armadillo and the giant armadillo-like Glyptotherium, and giant beavers, as well as birds like giant condors, other iterators and terror birds.
Among the most recognizable Eurasian species are the woolly mammoth, steppe mammoth, straight-tusked elephant, European hippopotamuses, aurochs, steppe bison, cave lion, cave bear, cave hyena, Homotherium, Irish elk, giant polar bears, woolly rhinoceros, Merck's rhinoceros, narrow-nosed rhinoceros, and Elasmotherium. Skull of Canaries bravo (Tenerife giant rat).
^ Elias, Scott A.; Short, Susan K.; Nelson, C. Hans; Birds, Hilary H. (1996). “Life and times of the Bering land bridge”.
“Radiocarbon evidence of mid-Holocene mammoths stranded on an Alaskan Bering Sea island”. ^ Reamer, Jelly W. F.; Rook, Lorenzo; Van Her Borg, Klaus; Post, Klaus; MOL, Dick; DE Los, John (2003).
“Late Pleistocene survival of the saber-toothed cat Homotheriumin northwestern Europe”. A. N.; Ho, S. Y. W.; Burger, J. ; Yamaguchi, N.; High am, T. F. G.; Wheeler, H. T.; Roosendaal, W.; Her, A. V.; Sotnikova, M.; Kuznets ova, T.; Baryshnikov, G. F.; Martin, L. D.; Harrington, C. R.; Burns, J.
“Paleogeography of lions (Panther Leo SSP.) Reveals three distinct taxa and a late Pleistocene reduction in genetic diversity”.
^ Ghetto, Elena; Rook, Lorenzo (2015). “The remarkable Panther parts (Felipe, Mammalian) record from Equip (Massey, Italy): Taxonomy, morphology, and paleoecology”.
^ Cooper, A.; Turned, C.; Hughes, K. A.; Brook, B. W.; McDonald, H. G.; Bradshaw, C. J. “Abrupt warming events drove Late Pleistocene Arctic megafaunal turnover”.
^ White, T. D.; Saw, B.; Augusta, D.; Gilbert, H.; Richards, G. D.; Suva, G.; Clark Howell, F. (2003). “Pleistocene Homo sapiens from Middle Awash, Ethiopia”.
^ Nazi, S.; Donkey, K.; Format, C.; Bauer, C. C.; Killer, O.; Stood, J. Í.; Pap, I.; Malleoli, F.; Boyle, P.; Corneille, M.; Condemn, S.; Ronchitelli, A.; Harvard, K.; Weber, G. W. (2011). “Early dispersal of modern humans in Europe and implications for Neanderthal behavior”.
^ High am, T.; Compton, T.; Stringer, C.; Jacobi, R.; Shapiro, B.; Trinkets, E.; Chandler, B.; Growing, F.; Collins, C.; Hill son, S.; o’Higgins, P.; Fitzgerald, C.; Pagan, M. (2011). “The earliest evidence for anatomically modern humans in northwestern Europe”.
^ Pavlov, Pavel; Sense, John Inge; Intrepid, Spain (2001). “Human presence in the European Arctic nearly 40,000 years ago”.
“Mamontovaya Surya:an enigmatic, nearly 40000 years old Paleolithic site in the Russian Arctic” (PDF). ^ Titular, V. V.; Sikorsky, P. A.; Girl, E. Y.; Basilar, A. E.; Turkey, V. E.; Kulak, S. A.; Astrakhan, S. N.; Pavlova, E. Y.; Asimov, M. A.
“The Yang RHS Site: Humans in the Arctic Before the Last Glacial Maximum”. ^ Titular, V. V.; Dishonor, A. N.; Pavlova, E. Y.; Nikolai, P. A.; Super, K. E.; Molotov, R. N. (2016).
“Early human presence in the Arctic: Evidence from 45,000-year-old mammoth remains”. ^ Tame, E.; Division, T.; Radley, M.; Metal, M.; Smith, D. G.; Mulligan, C. J.; Brave, C. M.; Richards, O.; Martinez-Labarga, C.; Khusnutdinova, E. K.; Fedora, S. A.; Golubenko, M. V.; Stefano, V. A.; Guinea, M. A.; Zhdanov, S. I.; Ossipova, L. P.; Samba, L.; Nevada, M. I.; Pierre, J. E.; Valleys, R.; Mali, R. S. (2007).
“Bringing Standstill and Spread of Native American Founders”. ^ Marc A. Carrasco, Anthony D. Barnes, Russell W. Graham Quantifying the Extent of North American Mammal Extinction Relative to the Pre-Anthropogenic Baseline plosive.org December 16, 2009, Nickerson, Colin (September 25, 2007), “Cosmic blast may have killed off megafauna Scientists say early humans doomed, too”, Boston.com, Boston, MA: The Boston Globe, p. A2 ^ a b Boissoneault, Lorraine.
“Are Humans to Blame for the Disappearance of Earth's Fantastic Beasts?” Although some debate persists, most of the evidence suggests that humans were responsible for extinction of this Pleistocene fauna, and we continue to drive animal extinctions today through the destruction of wild lands, consumption of animals as a resource or a luxury, and persecution of species we see as threats or competitors.
^ a b Cooper, Alan; Turned, Chris; Hughes, Konrad A.; Brook, Barry W.; McDonald, H. Gregory; Bradshaw, Corey J. “Abrupt warming events drove Late Pleistocene Arctic megafaunal turnover”.
^ Random, Christopher; Fairly, Siren; Handel, Brody; Evening, Jens-Christian (4 June 2014). “Global late Quaternary megafauna extinctions linked to humans, not climate change”.
“Historic and prehistoric humandriven extinctions have reshaped global mammal diversity patterns”. “Body size downgrading of mammals over the late Quaternary”.
Annual Review of Ecology, Evolution, and Systematic. ^ Miller, Gifford; McGee, John; Smith, Mike; Sooner, Nigel; Barnes, Alexander; Lehman, Scott; Vogel, Marilyn; Johnston, Harvey; Williams, Doug; Clark, Peter; Florian, Christopher (2016-01-29).
“Human predation contributed to the extinction of the Australian megafaunal bird Genyornis Newton 47 key”. ^ van der Years, Sander; Miller, Gifford H.; et al. (January 20, 2017).
“Humans rather than climate the primary cause of Pleistocene megafaunal extinction in Australia”. ^ O'Keefe FR, FET EV, Harris JM.
Compilation, calibration, and synthesis of fauna and floral radiocarbon dates, Ranch La Area, California. Cont rib Sci 518: 1–16 ^ O'Keefe, F. Robin, Binder, Wendy J., Frost, Stephen R., Sadler, Rudyard W., and Van Valkenburgh, Blair 2014.
Cranial morphometrics of the dire wolf, Cans virus, at Ranch La Area: temporal variability and its links to nutrient stress and climate. In C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.
), Evolution of Tertiary Mammals of North America 1:236-242 ^ R. M. Noway. Maryland, Johns Hopkins University Press (edited volume) II ^ “North American Glyptodon”.
Manifests extents Del Quaternary de la Provincial del Chico (Argentina) y SU relation con quells Del ester DE la region Pamplona y DE Chile. Re vista geological DE Chile 31(1):65-87 ^ O. P. Recabarren, M. Piano, M. T. Albert.
La Familiar Gomphotheriidae en America del SUR: evidence DE molars all north DE la Patagonia Chilean. ^ Gun, Philipp; Harvard, Katerina; Nazi, Stefano; Caber, Adeline Le; Bergmann, Inca; Skinner, Matthew M.; Neubauer, Simon; Realize, Sarah E.; Bailey, Share E. (June 2017).
“New fossils from Rebel Proud, Morocco and the pan-African origin of Homo sapiens” (PDF). ^ Dublin, Jean-Jacques; Banner, Abdelouahed; Bailey, Share E.; Realize, Sarah E.; Neubauer, Simon; Skinner, Matthew M.; Bergmann, Inca; Le Caber, Adeline; Nazi, Stefano (2017-06-07).
“Archaic Hominin Populations in Asia before the Arrival of Modern Humans: Their Phylogeny and Implications for the Southern Denison”. ^ Death of the Megafauna ^ Extinct dwarf elephants from the Mediterranean islands Archived 2009-01-23 at the Payback Machine ; ^ North American Extinctions v. World ^ Mammoths and Humans as late Pleistocene contemporaries on Santa Rosa Island, Institute for Wildlife Studies 6th California Islands Symposium, Larry D. Abroad, et al., December 2003.
It is believed that megafauna initially came into existence in response to glacial conditions and became extinct with the onset of warmer climates. In temperate Eurasia and North America, megafauna extinction concluded simultaneously with the replacement of the vast periglacial tundra by an immense area of forest.
Glacial species, such as mammoths and woolly rhinoceros, were replaced by animals better adapted to forests, such as elk, deer and pigs. Reindeer (caribou) retreated north, while horses moved south to the central Asian steppe.
Most large, predominantly browsing animals lost their habitat and retreated to a narrowband in eastern Australia, where there was permanent water and better vegetation. The diprotodon, one of Australia's megafauna, may have survived on the Liverpool Plains of New South Wales until about 7000 years ago.
The term megafauna has Greek origins and means large animals”. Specifically, it refers to large animals who inhabited the earth’s ecosystem during previous periods and are extinct today.
The fossils of this Australian megafauna that resembles Kangaroo were found in many parts of Australia. Grasslands, forests, and woodlands formed the perfect habitat for the animal because, within these settings, they could easily get water, grass, leaves, and shrubs for food.
The name Regathering has a Greek origin meaning the “Great Beast.” This mammal also went by the name “the giant ground sloth” and it lived in South America from the early Pliocene period to the end of the Pleistocene period. From head to tail, the animal was about twenty feet long with a height that enabled it to feed on branches.
The Regathering tail was muscular and it used the tail together with the hind legs to form a tripod-like stand that supported its upper part of the body during feeding where the long forelimbs with curved claws pulled down tree branches. Regathering resembles the modern-day anteater and walked on its feet’s sides due to the intruding claws.
These animals had body armor that resembled that of a tortoise, however, the Glyptodont could not withdraw its heads. With sizes like that of a modern automobile (two tones), this animal effectively defended itself from larger and stronger predators.
Palaeoloxodon was a straight-tusked elephant that lived in Cyprus, Germany, Japan, India, Italy, England, and Malta. Cotylorhynchus belonged to the genus synopsis that lived during the Early Permian period in the present southern part of the North American continent.
This animal was the largest earth vertebrate during its time although some sources suggest that it was aquatic or semi-aquatic. The archegosaurs occupied the ecological niche of alligators and crocodiles and lived in South America, especially Brazil within a humid and tropical environment.
Other body features included short legs, a tail for swimming, sharp teeth, and an elongated and tapered snout making the general appearance to resemble that of a modern-day facial. Dunkleosteus lived during the Late Devonian period (358-382 million years ago) and belonged to the genus of Aphrodite placer fish.
In Greek, the second part of the name Dunkleosteus (steps) translates to “bone.” Species of this genus include some of the largest placers to ever live, most grew up to lengths of 19.7 feet and weighed up to 1.1 short tons. Just like modern suction feeders, the Dunkleosteus also opened and closed its jaws in quick succession and had a bite force of approximately 6,000 N at the tip and 7,400 N at the blade edge.
Recent fossil reconstructions show that some species had shark-like structure, including a strong anterior lobe on the tail. The Jaekelopterus lived during the Early Devonian age and it was a giant predatory eurypterid which is a group of aquatic arthropods.
According to analyses, the Jaekelopterus had high visual acuity through its compound eyes. Jaekelopterus was also an active predator that lived in estuaries and freshwater systems although initial suggestions pointed at a marine habitat.
In Ohio, the megafauna included mastodon, mammoth, ground sloth, peccary, giant beaver, horse, bison, muskox, stag moose, short-faced bear, and probably dire wolf and saber-toothed cat.