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Gracile australopithecines Fossil range: Pliocene
Australopithecus africanus
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Subfamily: Homininae Tribe: Hominini Subtribe: Hominina Genus: Australopithecus R.A. Dart, 1925
Species
†A. afarensis ("Lucy") †A. africanus †A. anamensis †A. bahrelghazali †A. garhi Formerly Australopithecus, now Paranthropus †P. aethiopicus †P. robustus †P. boisei Sad Sappy Sucker (sometimes written as SadSappySucker) is the name of the 2001 album release by indie rock band Modest Mouse. ... Image File history File links This is a lossless scalable vector image. ... The Pliocene epoch (spelled Pleiocene in some older texts) is the period in the geologic timescale that extends from 5. ... Image File history File links Austrolopithecus_africanus. ... Binomial name Dart, 1925 Australopithecus africanus was an early hominid, an australopithecine, who lived between 2-3 million years ago in the Pliocene. ... For other uses, see Scientific classification (disambiguation). ... For other uses, see Animal (disambiguation). ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the presence of sweat glands, including those that produce milk, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex... Families 15, See classification A primate is any member of the biological order Primates, the group that contains all the species commonly related to the lemurs, monkeys, and apes, with the latter category including humans. ... Genera The hominids are the members of the biological family Hominidae (the great apes), which includes humans, chimpanzees, gorillas, and orangutans. ... Tribes Gorillini Hominini Homininae is a subfamily of Hominidae, including Homo sapiens and some extinct relatives, as well as the gorillas and the chimpanzees. ... Genera Subtribe Panina Pan (chimpanzees) Subtribe Hominina Homo (humans) †Paranthropus †Australopithecus †Sahelanthropus †Orrorin †Ardipithecus †Kenyanthropus For an explanation of very similar terms see Hominid Hominini is the tribe of Homininae that only includes humans (Homo), chimpanzees (Pan), and their extinct ancestors. ... Hominina is a subtribe that inludes Homo sapiens, Australopithecus, as well as prehistoric humans. ... Raymond Dart, holding the Taung Child skull Raymond Dart (February 4, 1893–22 November 1988) was an Australian anatomist and anthropologist best known for his discovery in 1924 of a fossil of Australopithecus at Taung in Northwestern South Africa. ... Year 1925 (MCMXXV) was a common year starting on Thursday (link will display the full calendar) of the Gregorian calendar. ... For other uses, see Species (disambiguation). ... Binomial name Johanson & White, 1978 Australopithecus afarensis is an extinct hominid which lived between 3. ... Binomial name Dart, 1925 Australopithecus africanus was an early hominid, an australopithecine, who lived between 2-3 million years ago in the Pliocene. ... Binomial name †Australopithecus anamensis Leakey et al, 1995 Australopithecus anamensis is a fossil species of Australopithecus. ... Binomial name Australopithecus bahrelghazali Brunet et al. ... Binomial name †Australopithecus garhi Asfaw et al, 1997 Australopithecus garhi is a gracile australopithecine species whose fossils were discovered in 1996 by a research team led by Ethiopian paleontologist Berhane Asfaw and including Tim White, an American paleontologist researcher. ... Species †Paranthropus aethiopicus †Paranthropus boisei †Paranthropus robustus The robust australopithecines, members of the extinct hominin genus Paranthropus (Greek para beside, Greek anthropos human), were bipedal hominins that probably descended from the gracile australopithecine hominins (Australopithecus). ...

The gracile australopithecines (members of the genus Australopithecus) (Latin australis "of the south", Greek pithekos "ape") are a group of extinct hominids that were closely related to humans. For other uses, see Genus (disambiguation). ... In biology and ecology, extinction is the ceasing of existence of a species or group of species. ... A hominid is any member of the biological family Hominidae (the great apes), including the extinct and extant humans, chimpanzees, gorillas, and orangutans. ... Species Homo sapiens See text for extinct species. ...

Evolution

Gracile australopithecines shared several traits with modern apes and humans and were widespread throughout Eastern and Northern Africa as early as 3.9 to as late as 3 million years ago. The earliest evidence of fundamentally bipedal hominids can be observed at the site of Laetoli in Tanzania. These hominid footprints are remarkably similar to modern humans and have been positively dated as 3.7 million years old. Until recently, the footprints have generally been classified as Australopithecine because that had been the only form of pre-human known to have existed in that region at that time; however, some scholars have considered reassigning them to a yet unidentified very early species of the genus Homo. Categories: Africa geography stubs | Eastern Africa ... Categories: Africa geography stubs | North Africa ... Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its hominid footprints, preserved in volcanic ash (Site G). ... For other uses, see Species (disambiguation). ... Species Homo sapiens See text for extinct species. ...

Australopithecus anamensis, Australopithecus afarensis and Australopithecus africanus are among the most famous of the extinct hominids. A. africanus used to be regarded as ancestral to the genus Homo (in particular Homo erectus). However, fossils assigned to the genus Homo have been found that are older than A. africanus. Thus, the genus Homo either split off from the genus Australopithecus at an earlier date (the latest common ancestor being A. afarensis or an even earlier form, possibly Kenyanthropus platyops), or both developed from a yet possibly unknown common ancestor independently. Binomial name †Australopithecus anamensis Leakey et al, 1995 Australopithecus anamensis is a fossil species of Australopithecus. ... Binomial name Johanson & White, 1978 Australopithecus afarensis is an extinct hominid which lived between 3. ... Binomial name Dart, 1925 Australopithecus africanus was an early hominid, an australopithecine, who lived between 2-3 million years ago in the Pliocene. ... Species Homo sapiens See text for extinct species. ... Binomial name (Dubois, 1892) Synonyms † Pithecanthropus erectus † Sinanthropus pekinensis † Javanthropus soloensis † Meganthropus paleojavanicus Homo erectus (Latin: upright man) is an extinct species of the genus Homo. ... For other uses, see Fossil (disambiguation). ... Binomial name †Kenyanthropus platyops Leakey et al. ...

According to the Chimpanzee Genome Project, both human (Ardipithecus, Australopithecus and Homo) and chimpanzee (Pan troglodytes and Pan paniscus) lineages diverged from a common ancestor about 5-6 million years ago, if we assume a constant rate of evolution. It is theoretically more likely for evolution to happen slower (older), as opposed to quicker, from the date suggested by a gene clock (the result of which is given as an "youngest common ancestor", i.e. the latest possible date of diversion.) However, more recently discovered hominids are somewhat older than the molecular clock would theorize. Sahelanthropus tchadensis, commonly called "Toumai" is about 7 million years old and Orrorin tugenensis lived at least 6 million years ago; the location of the mastoid of both indicate that they were bipedal and had therefore diverged from the common ancestor much further back along the evolutionary trail. Since little is known of them, they remain controversial among scientists since the molecular clock in humans has determined that humans and chimpanzees had an evolutionary split at least a million years later. One theory suggests that humans and chimpanzees diverged once, then interbred around one million years after diverging. ^[1] The Chimpanzee Genome Project is an effort to determine the DNA sequence of the genome of the closest living human relatives. ... Species †Ardipithecus kadabba †Ardipithecus ramidus Ardipithecus is a very early hominin genus (subfamily Homininae). ... Type species Simia troglodytes Blumenbach, 1775 distribution of Species Pan troglodytes Pan paniscus Chimpanzee, often shortened to chimp, is the common name for the two extant species of apes in the genus Pan. ... Binomial name Pan troglodytes Blumenbach, 1799 The Common Chimpanzee (Pan troglodytes) is a great ape. ... Binomial name Pan paniscus Schwarz, 1929 The Bonobo (Pan paniscus), sometimes called the Pygmy Chimpanzee, is one of the two species comprising the genus Pan; both members of that genus are technically chimpanzees, though the term is frequently used to refer only to the other member of the genus, Pan... The molecular clock (based on the molecular clock hypothesis (MCH)) is a technique in genetics, which researchers use to date when two species diverged. ... Binomial name Sahelanthropus tchadensis Sahelanthropus tchadensis is an early fossil hominid, approximately 7 million years old from the Miocene. ... Binomial name †Orrorin tugenensis Senut et al, 2001 Orrorin tugenensis is considered as the second oldest possible hominin ancestor related to modern humans (other than Sahelanthropus tchadensis) and is the only species classified in genus Orrorin. ... Bipedalism is standing, or moving for example by walking, running, or hopping, on two appendages (typically legs). ... The molecular clock (based on the molecular clock hypothesis (MCH)) is a technique in genetics, which researchers use to date when two species diverged. ...

As molecular evidence has accumulated, the constant-rate assumption has proven false—or at least overly general. However, while the molecular clock cannot be blindly assumed to be true, it does hold in many cases, and these can be tested for. For example, molecular clock users are developing workaround solutions using a number of statistical approaches including maximum likelihood techniques and later Bayesian modeling. Bayesian refers to methods in probability and statistics named after the Reverend Thomas Bayes (ca. ...

Morphology

The brains of most species of Australopithecus were roughly 35% of the size of that of a modern human brain, which means it's 450-500cc, samller than a modern human(1400cc). Most species of Australopithecus were diminutive and gracile, usually standing no more than 1.2 and 1.4 m (approx. 4 to 4.5 feet) tall. In several variations of Australopithecine there is a considerable degree of sexual dimorphism, meaning that males are larger than females. Modern hominids do not appear to display sexual dimorphism to the same degree- particularly, modern humans display a low degree of sexual dimorphism, with males being 15% larger than females, on average. In Australopithecines, males can be up to 50% larger than females. New research suggests that sexual dimorphism may be far less pronounced than this, but there is still much debate on the subject. The human brain In animals, the brain (enkephalos) (Greek for in the skull), is the control center of the central nervous system, responsible for behavior. ... This article is about modern humans. ... Female (left) and male Common Pheasant, illustrating the dramatic difference in both color and size, between the sexes Sexual dimorphism is the systematic difference in form between individuals of different sex in the same species. ...

Species variations

Although opinions differ as to whether the species aethiopicus, boisei and robustus should be included within the genus Australopithecus, the current consensus in the scientific community is that they should be placed in a distinct genus, Paranthropus, which is believed to have developed from the ancestral Australopithecus line. Up until the last half-decade, the majority of the scientific community included all the species shown in the box at the top of this article in a single genus. Paranthropus, being more massive and robust, was also morphologically distinct from Australopithecus, and its specialized physiology also implies that its behavior was quite different from that of its ancestor. Species †Paranthropus aethiopicus †Paranthropus boisei †Paranthropus robustus The robust australopithecines, members of the extinct hominin genus Paranthropus (Greek para beside, Greek anthropos human), were bipedal hominins that probably descended from the gracile australopithecine hominins (Australopithecus). ... The term morphology in biology refers to the outward appearance (shape, structure, colour, pattern) of an organism or taxon and its component parts. ... This article or section does not cite any references or sources. ...

Evolutionary role

Re-creation of A. afarensis from Laetoli (American Museum)

   

The fossil record seems to indicate that Australopithecus is the common ancestor of the distinct group of hominines, now called Paranthropus (the "robust australopithecines"), and most likely the genus Homo which includes modern humans. Although the intelligence of these early hominines was likely no more sophisticated than modern apes, the bipedal stature is the key evidence which distinguishes the group from previous primates who are quadrupeds. The morphology of Australopithecus upsets what scientists previously believed, namely, that large brains preceded bipedalism. If A. afarensis was the definite hominine which left the footprints at Laetoli, it strengthens the notion that A. afarensis had a small brain but was a biped. Fossil evidence such as this has made it clear that bipedalism far predated large brains. However, it remains a matter of controversy how bipedalism first evolved millions of years ago (several concepts are still being studied). The advantages of bipedalism allowed hands to be free for grasping objects (e.g. carrying food and young), and allowed the eyes to look over tall grasses for possible food sources or predators. However, many anthropologists argue that these advantages were not large enough to cause bipedalism. Image File history File links Laetoliafar. ... Image File history File links Laetoliafar. ... Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its hominid footprints, preserved in volcanic ash (Site G). ... This article does not cite any references or sources. ... Image File history File links 3d_glasses_red_cyan. ... Species †Paranthropus aethiopicus †Paranthropus boisei †Paranthropus robustus The robust australopithecines, members of the extinct hominin genus Paranthropus (Greek para beside, Greek anthropos human), were bipedal hominins that probably descended from the gracile australopithecine hominins (Australopithecus). ... A quadruped is an animal having exactly four walking legs. ... Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its hominid footprints, preserved in volcanic ash (Site G). ...

A recent study of primate evolution and morphology noted that all apes, both modern and fossil, show skeletal adaptations to upright posture of the trunk, and that fossils such as Orrorin tugenensis indicate bipedalism around 5 to 8 millian years ago, around the time of the split between humans and chimpanzees indicated by genetic studies. This suggested that that upright, straight-legged walking originally evolved as an adaptation to tree-dwelling. Studies of modern orangutans in Sumatra showed that these apes use four legs when walking on large stable branches, swing underneath slightly smaller branches, but are bipedal and keep their legs very straight when walking on multiple small flexible branches under 4 cm. diameter, while also using their arms for balance and additional support. This enables them to get nearer to the edge of the tree canopy to get fruit or cross to another tree. Climate changes around 11 to 12 million years ago affected forests in East and Central Africa so that there were periods when openings prevented travel through the tree canopy, and at these times ancestral hominids could have adapted the upright walking behaviour for ground travel. It is suggested that the ancestors of gorillas and chimpanzees became more specialised in climbing vertical tree trunks or lianas, using a bent hip and bent knee posture which matches the knuckle-walking posture they use for ground travel. Humans are closely related to these apes, and share features including wrist bones apparently strengthened for knuckle walking.^[2][3] Binomial name †Orrorin tugenensis Senut et al, 2001 Orrorin tugenensis is considered as the second oldest possible hominin ancestor related to modern humans (other than Sahelanthropus tchadensis) and is the only species classified in genus Orrorin. ... This article is about the primate. ... Sumatra (also spelled Sumatera) is the sixth largest island in the world (approximately 470,000 km²) and is the largest island entirely in Indonesia (two larger islands, Borneo and New Guinea, are partially in Indonesia). ... Type species Troglodytes gorilla Savage, 1847 distribution of Gorilla Species Gorilla gorilla Gorilla beringei The gorilla, the largest of the living primates, is a ground-dwelling omnivore that inhabits the forests of Africa. ... Type species Simia troglodytes Blumenbach, 1775 distribution of Species Pan troglodytes Pan paniscus Chimpanzee, often shortened to chimp, is the common name for the two extant species of apes in the genus Pan. ...

Radical changes in morphology took place before gracile australopithecines evolved; the pelvis structure and feet are almost indistinguishable in comparison to modern humans. The teeth are aligned just as modern humans with small canines; however, Paranthropus evolved a larger thicker dentition. Australopithecines faced one particular challenge while living on the savanna. They were the slowest-moving primates at the time and many fell prey to carnivorous creatures (lions and the extinct Dinofelis). Savannah redirects here. ... Binomial name Panthera leo (Linnaeus, 1758) The Lion (Panthera leo) is a mammal of the family Felidae. ... Species Dinofelis abeli Dinofelis barlowi Dinofelis diastemata Dinofelis paleoonca Dinofelis piveteaui Dinofelis therailurus Dinofelis is a genus of machairodontin saber-toothed cats belong to the tribe Metailurini that lived in Europe, Asia, Africa and North America approximately 5-1. ...

Most species of Australopithecus were not any more adept at tool use than modern non-human primates, yet modern African apes, chimpanzees, and most recently gorillas, have been known to use simple tools (i.e. cracking open nuts with stones and using long sticks to dig for termites in mounds), and chimpanzees have been observed using spears (not thrown) for hunting. However, Australopithecus garhi does appear to have been the most advanced of the line with its presumably older stone tool artifacts than the earliest genus homo member known so far, Homo habilis. A. garhi's remains have been found with tools and butchered animal remains, suggesting the incipience of a very primitive tool industry. This led many scientists to suspect that A. garhi may be the ancestor of the Homo genus. However, further evidence may help anthropologists and scientists to determine the true ancestor species. Type species Troglodytes gorilla Savage, 1847 distribution of Gorilla Species Gorilla gorilla Gorilla beringei The gorilla, the largest of the living primates, is a ground-dwelling omnivore that inhabits the forests of Africa. ... Families Mastotermitidae Kalotermitidae Termopsidae Hodotermitidae Rhinotermitidae Serritermitidae Termitidae Wikispecies has information related to: Isoptera Termites, sometimes known as white ants, are a group of social insects usually classified at the taxonomic rank of order Isoptera. ... Binomial name †Australopithecus garhi Asfaw et al, 1997 Australopithecus garhi is a gracile australopithecine species whose fossils were discovered in 1996 by a research team led by Ethiopian paleontologist Berhane Asfaw and including Tim White, an American paleontologist researcher. ... Binomial name Leakey et al, 1964 Homo habilis (IPA ) (handy man, skillful person) is a species of the genus Homo, which lived from approximately 2. ...

Diet

In a 1979 preliminary microwear study of Australopithecus fossil teeth, anthropologist Alan Walker theorized that Austrolopithecus may have been fruitarian.^[4] However, newer methods of studying fossils have shown that Australopithecus was likely omnivorous. In 1992, isotope studies of the strontium/calcium ratios in Australopithecus fossils showed that the species almost certainly consumed animals. These findings were confirmed in 1994 using stable carbon isotopic analysis.^[5] Fructarians (or fruitarians) are a subgroup of vegans who eat only the fruit of plants. ... Pigs are omnivores. ...

Notable Specimens

• Laetoli footprints
• AL 129-1
• Lucy
• STS 5 (Mrs. Ples)
• STS 14
• STS 71
• Taung Child
• Selam

Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its hominid footprints, preserved in volcanic ash (Site G). ... AL 129-1 is the fossilized knee joint of the species Australopithecus afarensis. ... Lucy (also given a second (Amharic) name: ድንቅነሽ dinqineš, or “Dinkenesh,” meaning “You are beautiful” or you are wonderful[2]) is the common name of AL 288-1, the 40% complete Australopithecus afarensis skeleton discovered on November 24, 1974 by the International Afar Research Expedition (IARE; director: Maurice Taieb, co-directors... Archaeologists at Sterkfontein cave, where Mrs. ... STS 14 is a fossilized pelvis, vertebral column and fragmentary rib and femur of the species Australopithecus africanus. ... STS-71 was a Space Shuttle program mission. ... Taung Child refers to the fossil of a skull specimen of Australopithecus africanus. ... Selam (DIK-1/1) is the fossilized skull and other skeletal remains of a 3-year-old Australopithecus afarensis female whose bones were first found in Dikika, Ethiopia in 2000. ...

References

• Barraclough, G. (1989). in Stone, N. (ed.): Atlas of World History, 3rd edition, Times Books Limited. ISBN 0-7230-0304-1. 
• Leakey, Richard (1994). The Origins of Human Kind. ISBN 0-465-03135-8. 
• White, Tim D., et al. "Asa Issie, Aramis and the Origin of Australopithecus." Nature 440 (April 13, 2006), 883-89.

1. ^ Bower, Bruce (May 20, 2006). "Hybrid-Driven Evolution: Genomes show complexity of human-chimp split". Science News 169 (20): 308. 
2. ^ BBC - Science & Nature - The evolution of man. Mother of man - 3.2 million years ago. Retrieved on 2007-11-01.
3. ^ Thorpe S.K.S.; Holder R.L., and Crompton R.H. (24 May 2007). PREMOG - Supplementry Info. Origin of Human Bipedalism As an Adaptation for Locomotion on Flexible Branches. Primate Evolution & Morphology Group (PREMOG), the Department of Human Anatomy and Cell Biology, the School of Biomedical Sciences at the University of Liverpool. Retrieved on 2007-11-01. “Based on computer simulations of the mechanics of motion in fossil human ancestors such as the famous 'Lucy' skeleton, our research group has long argued that early human ancestors would have walked upright, rather than semi-crouched, as the old 'up from the apes' view has suggested ... Now, research on the orangutan, suggests that upright walking may have been a basic element of the lifestyle of the earliest ancestors of modern apes, including humans, which would have been tree-dwelling specialists on ripe fruit, living among the fine branches of tropical forest trees.”
4. ^ Billings, Tom. Humanity's Evolutionary Prehistoric Diet and Ape Diets--continued, Part D).
5. ^ Billings, Tom. Comparative Anatomy and Physiology Brought Up to Date--continued, Part 3B).

In 1977, Leaky sat next to the rare Half Monkey Half Man, who took a bite out of him, and made Leaky cry. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 305th day of the year (306th in leap years) in the Gregorian calendar. ... is the 144th day of the year (145th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... The University of Liverpool is a university in the city of Liverpool, England. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 305th day of the year (306th in leap years) in the Gregorian calendar. ...

See also

• Aramis, Ethiopia
• List of fossil sites (with link directory)
• List of hominina (hominid) fossils (with images)

Aramis, Afar, Ethiopia Aramis is a village and archaeological site in the Middle Awash region of Ethiopia, with remains of Australopithecus found there. ... List of fossil sites: // ^ http://www. ... The following charts give a brief overview of several notable fossil finds relating to human evolution. ...

External links

Wikibooks has a book on the topic of

Introduction to Paleoanthropology

Wikispecies has information related to:

Australopithecus

• Why australopithecines became bipedal

This article does not cite any references or sources. ... The following charts give a brief overview of several notable primate fossil finds relating to human evolution. ... Human evolutionary genetics studies how one human genome differs from the other, the evolutionary past that gave rise to it, and its current effects. ...