australopithecus anamensis

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