human ancestors Flashcards
Sahlanthropus tchadensis (pre-aus)
7-6 mya by M. Burnet in Chad. 350 cc, which is ape like. Massive browridge, nonhoning chewing complex, and lived in forests. Mostly bipedal based on foramen magnum. suggested it existed close to divergence of the common ancestor for apes/humans.
Orrorin tugenesis (pre-aus)
6 mya by Senut & Pickford in Tugan Hills/Lake Turkana, Kenya. Mostly post cranial elements with mandible fragments. Suggestive of efficient bipedalism because of the top of the femur that articulates with the hop was relatively long. Chimp like teeth and lived in a dry forest environment. Hand phalanx resembles ape (tree time) & nonhoning.
Ardipithecus kadabba
Middle Awash, Ethiopia. Post cranial bones and teeth. 5.8 - 5.2 mya and lived in a mixed woodland environment (contradicts that hominins evolved in open grassland as thought by Darwin etc.). Big toe is flat and broad, which indicates push off by big toe during locomotion. Canines wore from tip, some honing.
Ardipithecus ramidus
Ethiopia, 5.5-5.4 mya. May have been bipedal, but had an opposable hallux and was not flexible. Many primitive ape like characteristics (phalanges curved for trees). Thin enamel, canines wore from tip, and forward foramen magnum.
Australopithecines (general)
4 - 1 mya. 9 different species, represents diversification of hominids. Robust and gracile forms. Characteristics include small brain, small canines, large premolars, and large molars. heavy chewing (hard foods) & rare/no tool use.
Australopithecus anamensis
4 mya found in Aramis, Ethiopia. Broadly similar to Ardipithecus, possible relationship. Ape like characteristics include large canines and parallel tooth rows. Bipedal femur and human like ankle. Woodlands.
Australopithecus afarenis
Donald Johanson. 40% of skeleton Lucy. Many ape like characteristics and a true biped. Found in Hadar, Ethiopia, 3.6 - 3.0 mya. Primitive characteristics include parallel teeth, less than 500 cc, ape like face proportions, curved phalanges, and long arms.
Au. afarenis Laetoli footprints
Laetoli, Kenya, 3.6 mya. Fossil trackway created after rain turned the volcanic ash into mud and then covered in a new layer of ash.
Australopithecus (Kenyanthropus) platyops
3.5 mya, with 400-500 cc. Discovered by Leaky, west of Lake Turkana. Derived characteristics include flat faces and small molars. Same time as Au. afarensis (Lucy). Woodlands.
Australopithecus garhi
2.5 mya, E. Africa, small brain 450 cc, larger teeth than Au. afarensis, primitive nose projection. Some features indicate it may be ancestral to early Homo because of gracile features and arm/leg ratio is more human like. May have used tools (cut animal bones found). Lakeshore.
Robust australopithecines (paranthropus)
3 - 1 mya. Characteristics include 410-530 cc, sagittal crest, very large teeth, and dish faced. 3 members of the genus: P. boisei, P. aethiopicus, and P. robustus (Africa).
Australopithecus (Paranthropus) boisei
2.3 - 1.2 mya. OH 5 “Zinj”. Discovered by Leaky in Olduvai Gorge. 510 cc. large teeth (grinders of grasses). sagittal crest.
Australopithecus (Paranthropus) aethiopicus
The black skull, 2.5 mya, west Lake Turkana. Had a flatten cranial base, small brain 410 cc, very large teeth, sagittal crest, and perhaps ancestral to Au. boisei.
Australopithecus (Paranthropus) robustus
2 - 1.5 mya. may have lived in large groups and had a specialized diet of seeds, nuts, and tubers. sagittal crest, large premolars, longest surviving species of Au. lineage in S. Africa. Evolutionary side branch, disappeared 1 mya.
Australopithecus africanus
Gracile, 3.0 - 2.3 mya, found in Africa by Dart. Had a projecting face, small canines, post-orbital constriction. Found in rock quarries in ancient sinkholes. Larger teeth than Lucy.
Taung Baby (Au. africanus)
Discovered in 1925 by Raymond Dart. Was not immediately accepted as a hominin because people believed humans came from Europe, not Africa.
Piltdown Man
Had a big brain, but dates to the Middle Ages and was probably from an Orangutan. Fake, but rejected Dart’s Taung Baby this was found out.
Australopithecus sediba
Discovered in 2008 in Malapa Cave, South Africa. 2 individuals. 2 - 1.8 mya. 420 cc. Characteristics include small teeth, pelvis similar to Homo, and arm/leg ratio like australopithecines. Maybe tool use; contemporary version of robustus.
Early Homo
2.5 - 1.8 mya. Found in East Africa in East Turkana, Hadar, Olduvai Gorge, and in South Africa in Swartkrans.
Homo habilis
1.8 mya - 300kya in Java, Europe, Asia, Africa. 550-800 cc (631 avg). Sexual dimorphism: females 70 lbs and 49” (4’1”) and males 114 lbs and 62” (5’2”). Human like dentition and reduced face/larger cranium. ancestor to Homo erectus, definitely associated with stone tool use.
Homo habilis? OH 62
Found in 1980s in Olduvai Gorge by Donald Johanson. Australopithecine like post cranial remains. Skull cannot be reconstructed and may be related to Australopithecus because they have very long arms and short legs.
Australopithecus habilis?
Benard Wood and Mark Collard. Homo habilis very different from later homo. Primitive face, primitive limb proportions Should be considered australopithecine.
Lucy
3.5 ft tall and had somewhat short legs relative to the length of the arms and body trunk. male was 5-5.5 ft tall, indicating they walked similar to humans and that lucy was short. phalanges are the same length, but they are curved like pre-aus. suggests potential arboreal locomotion using the hands.
KNM ER 1470
sometimes considered Homo rudolfensis. found in Koobi Foora, Kenya. 1.8 mya. larger brain (750 cc), large premolars and molars, and larger body size.
Homo habilis - precision grip
flexor pollicis longus is a muscle in the forearm that originates at the radius. inserts on the ventral surface of the first terminal phalanx.
