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The American lion (Panthera leo atrox) – also known as the North American
lion, Naegele’s giant jaguar or American cave lion – is an extinct lion of
the family Felidae, endemic to North America during the Pleistocene epoch (340,000 to
11,000 years ago), existing for about 0.33 million years. It has been shown by genetic
analysis to be a sister lineage to the Eurasian cave lion (Panthera leo spelaea or P.
spelaea). It was part of the abundant Pleistocene megafauna, a wide variety of very
large mammals that lived at the time. The most abundant remains have come from
the La Brea Tar Pits.
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);
saber-toothed cats like Smilodon and the scimitar cat, Homotherium; dire wolves;
saiga; camelids such as two species of now extinct llamas and Camelops; at least two
species of bison; 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 and other teratorns. The nine-foot sabertooth salmon
lived at the time as well. In contrast, today the largest North American land animal is
the American bison.
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HISTORICAL GEOLOGY HUMAN ORIGINS
Primate Characteristics
Many primate characteristics developed in response to a life in the trees and
then a life on the open prairie, as forests were replaced by grasslands in the
Miocene epoch. Some of those characteristics are:
5 digits
opposable thumb
grasping hand
non-specialized teeth
complex vocal capability
closely-spaced eyes
}
smaller snout
} STEREOVISION
flatter face
}
color vision
The order PRIMATES is divided into 2 suborders; the more primitive
PROSIMIANS ("pre-monkeys"), which lack some of the characteristics
above (e.g. stereovision), and the more advanced ANTHROPOIDS
(including modern monkeys, apes and man), which have more of these
characteristics.
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The classification scheme is based on grouping together primates
with similar features into progressively narrower subdivisions (basic
taxonomy) i.e.
Order (e.g. Primates) = collection of similar suborders
Suborder (e.g. Anthropoidea) = collection of similar superfamilies
Superfamily (e.g. Hominoidea) = collection of similar families
Family (e.g. Hominidae) = collection of similar genera
Subfamily (e.g. Hominin) = (smaller) collection of similar genera
Genus (e.g. Homo – Latin for human) = collection of similar species
Species (e.g. sapiens) = collection of similar individuals
One of the families that developed from the anthropoids HOMINIDAE - consisted of primates with distinctive, Human-like
features. A subfamily – Hominins - included Homo sapiens, the
species of "modern Man“, but other species and genera belong to
this subfamily...
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The Emergence of Hominins
This part of the world has been
called "the cradle of Man",
because it's here that the
Hominins that were modern
Man's ancestors are believed to
have developed. Many fossil
Hominin bones, dating back to
the Pliocene (about 3-4 mybp)
have been found in this area.
These primates were basically
transitional between apes and
man, and were given the Genus
name "Australopithecus"
(meaning southern ape-man).
Several species were
discovered, including
Australopithecus africanus in
Harry Williams, Historical Geology
South Africa.
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The oldest Hominin bones have been found in Chad,
dating back to about 7 million yrbp. These are the oldest
Hominin fossils known and suggest that Hominins
developed between 6 and 7 million yrbp. The most
famous Hominin, discovered in 1974 at Hadar by Donald
Johanson, is the most complete Hominin skeleton yet
found. "Lucy" as the individual was informally named,
has the scientific name Australopithecus afarensis and is
about 3.5 million years old. These primitive ancestors of
modern humans were short (about 3.5-4.5 feet), upright
(but feet turned out), chinless, had a brow ridge and a
small brain (600-700 c.c) (not human). Ardipithecus ~4.4
million, seems transitional between apes and man (could
walk on grasping feet; not human; brain only 300 cc).
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The transition from
Australopithecines to hominins
of the genus Homo is not
marked by great anatomical
differences, however there is
some evidence of stone tool use
by the latter.
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What is a human?
Human | Define Human at Dictionary.com
www.dictionary.com/browse/human
A member of the species Homo sapiens;
a human being. A member of any of the extinct
species of the genus Homo, such as Homo erectus
or Homo habilis, that are considered ancestral or
closely related to modern humans.
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The first humans Homo rudolfensis
(right) and Homo
ergaster were roaming
the African plains about
2.5 million yrbp. Why
did Homo evolve from
Australopithecus?
Probably the change to
a drier cooler climate
and increase in
grasslands -> improved
bipedalism, greater
intelligence (larger
brain) and greater use of
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stone tools.
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Homo erectus
One of the descendents of the Australopithecus line was
Homo erectus, who appeared about 1.8 mybp and was the first
Hominin to migrate out of Africa to Eurasia. Homo erectus was
widespread in Africa and Asia by 1 mybp. Some of the differences
from Australopithecus = taller, excellent walker (feet did not turn
out) and, ESPECIALLY, a larger brain (775-1300 c.c. - modern
Man = 1200-1500 c.c.). This larger brain was reflected in a greater
use of tools, and maybe the development of FIRE and hunting in
bands (the evidence is inconclusive). The heavy brow ridge and
chinless jaw remained and distinguished Homo erectus from Homo
sapiens. Homo erectus is best remembered as the stage of BRAIN
ENLARGEMENT.
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Homo sapiens neanderthalensis
"Neanderthal Man", named after the
Neander Valley in Germany, was the
first species of modern Man (Homo
sapiens), appearing about 125,000
yrbp. The Neanderthal may be
considered a "subspecies" of Modern
Man - having many similarities, but
also a few differences e.g. they were
shorter, had the brow ridge and
chinless jaw. However, the rest of
their skeleton was the very similar to
modern Man's and their brains were
as large as ours. The Neanderthals had
a complex culture, including a belief
in "an afterlife”.
Neanderthal Modern Human
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Neanderthals were
skilled in the use of
fire and tools. They
commonly lived in
caves for shelter from
the harsh ice age
climate.
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Homo sapiens sapiens
"Cro-magnon Man" appeared
between 50,000 and 35,000 yrbp,
competing with the Neanderthals and
causing them to become extinct by
about 28,000 yrbp. The Cro-magnons
were essentially the same as modern
Man and we descended directly from
them. They developed culture even
further, including cave paintings in
Europe. Cro-magnons spread all over
the old world, and then, during the
last glaciation crossed the Bering
Strait land bridge into the "New
World" - North America. Originally
these Humans were hunter/gathers,
but by about 10-15 000 yrbp they
developed agriculture, built cities and
invented writing. The era of
"recorded history" had began. Harry Williams, Historical Geology
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Early Man In The Americas
Just when Man moved into North America is still not certain.
Debatable evidence =
30,000 year old flint tools in California.
28,000 year old roasted mammoth bones in California.
24,000 year old fire pits in Nevada.
23,000 year old obsidian blade in Mexico.
More sound evidence =
18,620-15,680 year old skull in California.
13,000-11,500 year old bone needle in Washington State.
spear points 13,000-11,000 years old in New Mexico.
11,000-9,000 year old flint tools in New Mexico.
The oldest known Human remains from South America are dated
at 12 600 yrbp.
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