Australopithecus anamensis
• Named by Meave Leakey and colleagues in 1994
• crania, teeth & postcrania
• 2 sites: Allia Bay & Kanapoi
• ca. 4.2-3.9 Ma
A. anamensis
LOUIS LEAKEY
Paranthropus boisei
• O.H. 5• discovered 1959• “robust”
australopithecine -- Zinjanthropus
• massive premolars and molars
• tiny canines and incisors• “Human Cuisinart”
Robust australopithecines = Paranthropus
• Late Pliocene - early Pleistocene deposits (2.5 -1 Ma)
• East & South Africa• massive molars• flatter, braoder, “dished”
faces• poorly known post-
cranial anatomy• similar in size to
Australopithecus
P. boisei -- female & male
KNM-ER 732 KNM-ER 406
• KNM-WT 17000• The “Black Skull”• 1985 discovery• W. Turkana (Kenya) &
Omo (Ethiopia)• ca. 2.8 - 2.2 Ma• primitive “robust”
australopithecine
Paranthropus aethiopicus
Gracile australopithecines
• Australopithecus africanus
• A. afarensis• A. anamensis• A. bahrelghazali
Robustaustralopithecines
• Paranthropus robustus
• P. aethiopicus• P. boisei
Generalized jaws & teeth Specialized jaws & teeth
Australopithecus garhi
• 1999 discovery by Asfaw, White and colleagues
• 2.5 Ma Ethiopia’s Middle Awash region
• garhi = “surprise”
A. garhi• craniodental &
postcranial remains (? association)
• Cranium:– small brain– prognathic face– very large teeth
• Post-cranium:– long legs– long forearms– < 5 ft tall
A. garhi
• Antelope remains from nearby site with cutmarks
• A. garhi or another hominin species is responsible (?)
• meat/marrow eating at an early date -- “hallmark” in human evolution
Hominin Trends
Australopithecus Homo
Encephalization
Dentition
Bone Marrow
22 March 2001
Kenyanthropus platyops nov. sp.• Disc. 1999 by Meave Leakey
• “flat-faced man of Kenya”
• 3.2 to 3.5 Ma – western
Lake Turkana
• contemporary with “Lucy”
• new genus -- controversial!
• KNM-WT 40000 = holotype
Kenyanthropus platyops nov. sp.
Confused about taxonomy?
HominidaeAustralopithecinaeHomininae
African apes not included
Australopithecines a SUBFAMILY
HominidaeGorillinaeHomininae
AustralopitheciniHominini
Australopithecines a TRIBE
http://www.mnh.si.edu/anthro/humanorigins/index.htm
Hominin Trends
Australopithecus Homo
Encephalization
Dentition
Homo habilis Leakey et al., 1964
• Olduvai Gorge– Beds I and II – 2.0 - 1.6 Ma
• “Handy Man”
• Tool association
• Passes “cerebral rubicon”
• Reduced molar size
Species based on ...
BED I Materials
• OH 4 -- isolated teeth• OH 6 -- cranial fragments• OH 7 -- mandible, parietals, hand bones (Type)• OH 8 -- partial foot• OH 10 -- toe bone• OH 35 -- tibia & fibula• OH 48 -- clavicle• OH 49 -- radius shaft
Species based on ...
BED II Materials
• OH 13 -- mandible, maxilla, cranial frags (Paratype)• OH 14 -- cranial fragments• OH 16 -- partial skull
The Cerebral Rubicon
Cranial Capacity (cm3)
A. africanus x = 440
P. boisei x = 515
H. habilis x = 640
H. erectus x = 1000
Defining Homo habilis
Craniodental Remains
• retreating chin region• relatively large I & C• small (narrow) molars
(relative to Australopithecus)
• M3 smaller than M2• Temporal lines never
meet in midline• slight postorbital
constriction
Postcranial Remains
• hand bones robust, prehensile
• stout big toe, adducted• hand & forelimbs indicate
climbing & weight support adaptations
Defining Homo habilis
OH 24 -- “Twiggy”
• Olduvai Gorge -- Lower Bed I • partial & reconstructed skull • female individual• cranial capacity ca. 590 cm3
(smaller than Australopithecus)
• slight postorbital constriction• domed forehead• expanded parietal region
Oldowan “Chopper” Technology
Homo habilis fossils (at one time or another)
Single Species Hypothesis
• C. Loring Brace & Milford Wolpoff (University of Michigan)
• 1960s & early 1970s
• All anatomical differences between hominin species is Intraspecific variation, not Interspecific variation.
• Only one species of hominin can exist at any one time.
Too much variation tojustify single species
Wolpoff (1964)• H. habilis is indistinct from A. africanus
• H. habilis diagnostic features insignificant …– Bed I = A. africanus– Bed II = early H. erectus
• H. habilis direct ancestor to H. sapiens -- descendedfrom A. africanus. H. erectusa dead end.
Robinson (1965)
Leakey (1966)
H. habilisH. erectus
H. sapiens
A. africanus