Prehistoric
cheetahs resembled modern cheetahs.
American
Cheetah
Scientists created an updated family tree for the ancient cats by comparing ancient DNA taken from
the preserved bones of the two sabertooths (a Smilodon specimen from Patagonia and a Homotherium specimen from the Yukon region)
and the American cheetah-like cat (a Miracinonyx specimen from the state of Wyoming) with DNA from modern felid (cat-family)
and carnivore species. The analysis shows that the sabertooth cats diverged early on from the ancestors of modern cats and
are not closely related to any living felid species.
The new data also shows that the American cheetah-like cat is genetically most closely related to the puma, rather than
to the true African cheetah (Acinonyx jubatus). While both Miracinonyx and the true cheetah Acinonyx resemble
one another physically, the genetic data indicate that this similarity is an example of evolutionary parallelism
in response to similar ecological pressures. With the new DNA data and fossil information from other studies, it is
likely that a puma-like ancestor that migrated to the New World may have given rise to Miracinonyx and ancestral
Puma a few million years ago, around the time that the North American prairie is thought to have undergone expansion.
As
the grasslands expanded in both North America and Africa, the separate cat species from both continents evolved to catch the new fleet-footed
herbivores.
To get a better grip for running at high speeds, the claws of M. trumani had even become only partially retractable.
True cheetahs have fully unretractable claws.
The First Cheetah?
In December 2008, it was announced that a nearly complete skull of a primitive cheetah found in Gansu Province,
China suggests that cheetahs originated in the Old World rather than
in the Americas.
The two million year old skull represents a new cheetah species, now dubbed Acinonyx kurteni. The animal probably
lived some time between 2.2 million and 2.5 million years ago, the researchers estimate, making the specimen one of the oldest
cheetah fossils identified to date.
With relatively few fossils to examine, scientists have long debated the cheetah's origins. These include the European Acinonyx
pardinensis (2.2 million years), and the North African Acinonyx aicha, (2.5 million years). Fossils of cheetah-like
cats in the Miracinonyx genus (American cheetahs in North America) date to
about 3.2 million years ago.
The skull of
Acinonyx kurteni is almost as old as the oldest cheetah fossils but has a unique set of 'primitive' characteristics
that strongly suggest it is an earlier ancestor to all cheetahs. In other words, although the other cheetah are
older (especially American Cheetah), they are a more evolved form of cheetah than Acinonyx kurteni.
For instance, the Acinonyx kurteni had enlarged sinuses for air intake during sprinting, causing the skull to
be tall and domed like modern cheetah skulls. But its teeth showed more primitive features than the others. This suggests
that running was very important to the species early on and the teeth evolved to their present form later.
Because
this new skull is more primitive than both cheetahs and Miracinonyx cats, and was found in China, it suggests an Eurasian/African ancestry of the entire group, with the Miracinonyx
cats (or their ancestors) dispersing into the Americas later.
Per Christiansen of the Zoological Museum of Denmark and Ji Mazák of the Shanghai
Science and Technology Museum detailed the finding in December 2008 in the journal
Proceedings of the National Academy of Sciences. The research was supported by a grant from the Carlsberg Foundation.
 American Lion
The extinct American lion
(Panthera atrox) lived throughout much of North America during the later part of the Pleistocene
(approximately 120,000 to 10,000 years ago). Fossil remains have been found in the American Southwest, Midwest, Southeast,
and Alaska, as well as parts of Mexico.
The American lion closely resembled the modern
African lion, but was about 25% larger and heavier than the living species. The closest cat to an American lion is the hybrid
liger, which also can get larger than 11.5 feet long.
Paleontologists hypothesize that Panthera
atrox lived and hunted in open grassland savanna habitats like modern lions. Whether they shared the same pride
structure as modern lions is debatable. It has been argued that the American lion more commonly hunted in pairs
or alone. This has been based on the fact that first lower molar teeth of American lions from Rancho La Brea can be separated
into male and female and that nearly equal numbers of both sexes are distributed through the sample from relatively very young
to very old individuals unlike the African lion. If they had the same pride structure as modern lions, there would have been
more females and cubs than males.
In some areas of its range, the American lion lived under cold
climatic conditions. They could have used caves or fissures for shelter from the cold weather. They could also have
lined their dens with grass or leaves, as the Siberian tiger does, another great cat that currently lives in the north.
We have a good idea what these animals
looked like since about one hundred specimens of American lions have been recovered from the La
Brea Tar Pits in Los Angeles, California. Since there are fewer American lions in the La Brea tar pits than other predators
such as saber-toothed cats (Smilodon
fatalis) or dire wolves (Canis dirus), American lions may have been smart enough to avoid
the hazard or their hunting methods and strategies simply didn't include preying upon entrapped animals to the same degree.
American lions likely preyed on deer, bison, mammoths, North American horses,
and other large herbivores.
The Holocene
extinction event wiped out most of the megafauna and the American lion's prey. That in itself may have cause
the gigantic lion's extinction. Their bones have also been found among the refuse of Paleolithic Native Americans, so hunting by humans may have contributed to their extinction as well.
Outside the Academy
of Natural Sciences in Philadelphia, Pennsylvania, the statue of paleontologist Joseph Leidy replica holds the jaw of the first specimen of
American lion discovered can be seen in his hand.
Cave
lions in Paleolithic art
 Cave Lions
Cave
lions are pretty well known due to their representation in Paleolithic art. These representations indicate that cave lions
had rounded, protruding ears, tufted tails, perhaps, faint tiger-like stripes, and that at least some had a "ruff" or primitive
mane around their neck, indicating males. Other artifacts (such as an ivory mask) indicate that they were featured
in Paleolithic religious rituals.
One
of the most exciting finds - the Lowenmensch ivory figures found in Germany - suggest the existence of a lion totem religion
where humans take on the hunting aspects of a lion.
The European Cave Lion (Panthera leo spelaea) first appeared in Europe
around 500,000 years ago and lived up to the near close of the last European Ice Age along with Neandertals and Homo sapiens.
The European Cave Lion was larger than most living cats today and grew to average weights and lengths meeting or exceeding
the largest ever recorded Siberian Tiger in modern time. The overall
head/body length averaged 11.5 feet with males weighing in at 880 lbs! This massive predator appeared similar
to a liger, but doubtlessly more aggressive. The American Lion can be considered a sub-species of the Cave Lion. Recent genetic data suggests that
the cave lion was a close, but separate, relative of modern lions.
Cave Lions lived in Europe roughly about 370,000 to 10,000
years ago. However, there have been some indications that it could have existed as recently as 2,000 years ago in the
Balkans.
In Greek
mythology, Herakles was pitted against an enormous lion whose skin was too touch to pierce with normal weapons.
To defeat the Nemean lion,
the hero had to strangle it and had to skin it using its own claws. Herakles then wore the impervious hide of the Nemean
lion as his armor. Could the basis for this myth be the old Paleolithic religion of lion men?
Emergence
of Modern Panthera
Until the late Pleistocene, lions were the most widespread of any mammal species next
to humans. The oldest lion-like fossil is known from Laetoli in Tanzania and is perhaps 3.5 million
years old. Although some scientists have identified the material as Panthera leo, all that can be
said is that the fossils pertain to a Panthera-like felid. The oldest confirmed records of Panthera leo
in Africa
are about 2 million years younger.
Lions appeared in Europe for the first time 700,000 years ago with the subspecies Panthera
leo fossilis in Italy. From this lion derived the later Cave Lion (Panthera leo spelaea),
which appeared about 300,000 years ago. During the upper Pleistocene the lion spread to North and South America, and developed into the
American Lion. Lions died out in northern Eurasia and America at the end of the last glaciation, about 10,000 years ago.
From the cave paintings we know that prehistoric lions had a short ruff instead of a mane and a slightly spotted or mottled
coat.
The oldest remains of a tiger-like cat, called Panthera palaeosinensis, were found in China and
Java. Somewhat smaller than modern tigers, this species lived about 2 million years ago, at the beginning of the Pleistocene.
The earliest tiger fossils date back to somewhere between 1.6 and 2 million years
ago and in approximately the same geographic distribution as modern tigers had a hundred years ago (when they still maintained
a substantial range) with the possible addition of Beringia (Alaska). Because of the spotty fossil record, it is
difficult to say which big cat evolved first. Some suggest the tiger came first from either South China or Siberia.
Both leopards and jaguars diverged from the lion about two million years ago. The
oldest leopard fossils have been found in the Siwalik Hills of the Indian subcontinent. They date to about 2 million years
ago (early Pleistocene). This evidence indicates that leopards may have originated in Asia, probably during the late Pliocene.
However, leopards did not all stay in Asia. They migrated and colonized Africa and other regions to a great extent. By the
middle of the Pleistocene, leopards were distributed extensively in East Asia, including Southeast Asia. Some migrated into
northeast Asia, including Japan. Leopards came into Europe during the middle of the Pleistocene. Fossils of them have been
found as far west as the British Isles. A large number of leopard fossils have been found in a cave site in Italy called Equi.
Leopards died out in Europe and in many parts of Asia. Today they are found in Africa and parts of southern Asia. Their numbers
have declined sharply, partly due to hunting. Of all the big cats, leopards had
the most powerful impact on our hominid ancestors. Many hominid bones bear the marks of leopard predation and primates
- to this day - are the favorite prey of leopards.
Jaguars evolved from
leopards during the early Pleistocene. They migrated from Eurasia to the North American continent by way of the Bering land
bridge. The jaguar arrived in North America about 1.5 million years ago. The
jaguars that came from Eurasia into the Americas had longer legs than the ones of today. They had evolved long legs to be
able to chase down prey on the steppes of Eurasia.
Interesting enough, one jaguar species lived in Europe around 1.6 million
years ago. It is called Panthera gomaszoegensis. Fossils of it have been discovered at the Olivola site in Italy. Other fossil
specimens of this jaguar species have been found in England, France, Spain, and Germany. Like their leopard cousins in Europe,
the European jaguars died out. The fossil record of jaguars now dates back to about 2 million years.
Jaguars of today are found in South America and Central America. However, as late as the 20th century, they have been sighted
as far north as the southern United States. Jaguar fossils have been discovered in various parts of North America,
including Nebraska and Washington state.
The fossil record of the
snow leopard is sparse, but it is believed that snow leopards evolved during the early Pleistocene. Some snow leopard
fossils have been found in the Altai caves of Central Asia. The evidence suggests that snow leopards did not migrate
to continents outside of Asia.
Clouded leopards are even harder to trace.
In fact, two species of clouded leopards emerged during the Pleistocene. DNA researchers estimate that since the middle to late Pleistocene Bornean and Sumatran
clouded leopards were most likely isolated from each other and unable to move freely between islands. Clouded
leopards were only able to move throughout the exposed shelf between Borneo and Sumatra at least once during the early or
middle Pleistocene. That would have been the only opportunity for a population to get to Borneo. The
Borneo clouded leopards were just recently named as a separate species.
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