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37 terms

Human Evolution

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Morotopithecus traits
Suspensory locomotion, ape like lumbar, tear dropped shape glenoid fossa, rigid femur (careful climbing), fistal femur wide and asymmetrical, popliteal groove gives stabilization during vertical climbing
Dryopithecus
- Large incisors, compressed canine, Reduced lumbar vertebrae with less mobility, ribcage wide, long clavicle, arms long relative to legs flexible wrist, hand capable of powerful grip, abduction at the hip (femur has head and neck).
Sivapithecus traits (arboreal quadruped)
Gracile supraorbital torus, orbits close together, proximal humerus monkey like, distal femur ape like, fossil primates found in India
Suspensory locomotion
Involves hanging or suspension of the body below or among the branches
Above-branch locomotion
Moving or sitting on top of the branches
Biogreography
Earliest miocene apes evolved in Africa-adaptive radiation of hominoidea, the radiation shifts with climate. Radiation begins in Uganda, then goes to Europe. Tropics spread and contract the miocene apes move with spreading and contracting tropical environments
Sahelanthropus ~7Ma (toumai) CHAD
Anterior foramen magnum, massive supra-orbital torus, less prognathic, sagittal crest, post-orbital constriction, large nuchal crest, 320-380cc, reduced canine.
Ororrin tugenensis 5.9-5.7 Ma Kenya
Thick enamel, ape like canine, large and medial lesser trochanter, shallow interchanteric fossa, arm retains suspensory capability, curved phalanx
Ardipithecus kadabba 5.8-5.2 Ma Aramis, Middle Awash , KENYA
Canine more conical shaped than apes, mesial ridge on canines, narrow lower second incisors, phalanx is very curved, but joint surfaces shows adaptations for bipedality.
Ardipithecus ramidus
Humerus shows minimal torsion, long curved metacarpals and phalanges, careful climbing, extremely abducted hallux
Bipedal features for Ardipithecus ramidus
Iliac blade is shorter and wider, more oriented toward the sagittal plane, greater trochanter looks like homonin
Ardipithecus ramidus 4.4-4.3Ma Afar region, KENYA ~ argument for monogamy
Monomorphic (one shape) canines demonstrates reduced sexual dimorphism
Ardipithecus ramidus 4.4-4.3 Ma Afar region, KENYA ~ diet & environment
Relatively thin enamel demonstrates a frugivorous diet, soft non-abrasive foods, stable isotope analysis C4 indicates it lived in open grassland environments
Raymond Dart
Found "taung" child 1924, South Africa - small teeth (apical wear and procumbent), anterior foramen magnum, endocast displayed lunate sulcus more derived condition like humans, taung child was rejected as common ancestor
Piltdown man 1912
Was a hoax, and fit a preconceived notion of what our ancestors looked like.1953 the hoax was finally realized.
Robert Broom - Sterkfontein (1930s)
Found an adult A. africanus
Australopithecus anamensis 4.2-3.9 Ma ~ plesiomorphies
Canines and incisors relatively large, U-shaped mandible, mandible slim and steep,most features of arms are primitive, curved strong phalanges, wrist bones indicate no precision grip for tool making.
Australopithecus anamensis 4.2-3.9 Ma ~ apomorphies
Canines have single wear surface, molar enlargement, thick enamel.
First family, Laetoli
Laetoli footprints indicates a striding rather than bent knee bipedality of A. afarensis
A. afarensis 3.6-2.9 Ma ~ Cranial plesiomorphies
380-550cc, large incisors and canines, alveolar prognathism, sagittal crest in some
A. afarensis 3.6-2.9 Ma ~ cranial apomorphies
Molariform premolars, more megadont 2.8X, parabolic shaped arcade (n some)
A. afarensis 3.6-2.9 Ma ~ post-crania plesiomorphies
Metacarpals capable of bearing weight, small apical tuffs on finger phalanges, curved phalanges, cranially oriented glenoid fossa, cone shaped thorax, small non-wedged shaped lumbar vertebrae, short femur
A. afarensis 3.6-2.9 Ma ~ post-crania apomorphies
Very wide pelvis, femur w/small head and long neck, valgus knee, 6 lumbar vertebrae, flat tibiotalar (ankle) joint, expanded calcaneus (heal), large 1st metatarsal, arched non-grasping foot, adducted hallux, short toe phalanges
Australopithecus africanus 3.0-2.4 Ma in South Africa ~ Plesiomorphies
Alveolar prognathism, post-orbital constriction,
Australopithecus africanus 3.0-2.4 Ma in South Africa ~ apomorphies
Sacrum tipped forward, wedge shaped lumbar vertebrae, less defined supra-orbital torus, reduced nuchal muscles, cheek bones more anterior, more loading on cheek teeth.
Swartkrans cave site South Africa
subterranean dolomite cavern filled with breccia over time, and comprised of 5 members, paranthropus found here
Australopithecus garhi 2.7-2.3 Ma, Ethiopia
Very wide canines, molarform premolars, large molars (megadontia), stone tools found nearby, oldest tools ever found (Oldowan core choppers), cut marks on bone found, possibly were scavenging.
Australopithecus sediba 1.9-1.78 Ma Malapa, South Africa ~ Plesiomorphies
Small cranial capacity 420cc, more pronounced supra-orbital torus, pelvis more derived like homo
Australopithecus sediba 1.9-1.78 Ma Malapa, South Africa ~ apomorphies
less post-orbital constriction, cheek bones less flaring, vertical chin area, reduced cheek teeth
Differences between gracile and robust Australopiths
Post-cranially very similar, cranially very different - lagre sagittal crests, megadontia, large zygomatic arches.
Apomorphies of Paranthropus as a genus
Very large cheek teeth, small incisors and canines shaped like incisiforms, dished midface, cheek bones more anterior, sagittal crest
Paranthropus aethiopicus 2.7-2.3 Ma Ethiopia and Kenya.
Anterior dentition larger than in later paranthropus, mre prognathic, 410cc, HUGE sagittal crest,
Paranthropus boisei 2.5-1.4 Ma, East Africa, Ethiopia to Malawi
Hyper robust, both males and females, sexual dimorphism present, the most robust taxon, cranium more flexed, sagittal crest more anterior, 500-540cc, a change in the architecture of chewing muscles.
Paranthropus robustus ~1.8-1.0 Ma, South Africa
Very similar to P. boisei but less robust,and smaller teeth than boisei
How to study diet
Teeth, masticatory system, wear patterns, isotopes
Australopith teeth
Flat chewing surface, reduction in molars, procumbent incisors, small incisors, reduced canines, low cusps, thick enamel, medium sized chewing surface, generalized dentition herbivore/omnivore
Paranthropus teeth
Small incisors, small canines, low cusps, thick enamel, megadont, specialized for hard food stuffs.