Ardipithecus ramidusTimespan: 4.4 mya

Region: Ethiopia

Specimens: 17 fossils, skull & postcranial

Discovered: White 1994

Holotype: ARA-VP-6/1

Lineage: descendent of Ar. kadabba

Environment: Woodland

Diet: Omnivorous

Speculation/theories: • Bipedal on ground, quadrupedal in trees; grasping large toe• possibly last common ancestor with chimps

D I A G N O S T I C F E AT U R E S

cranium• Temporals & occipitals smaller than A. afarensis• supraorbital ridge (browridge) unlike chimp• less facial prognathism in lower face than chimps, but considerable mid-face projection• foramen magnum (endocranial opening of hypoglossal canal) placed more anteriorly relative

to the internal auditory meatus• temporomandibular joint w/out definable articular eminence (very flat)• lacks the broad flaring zygomatics (cheekbones) of later australopithecinespostcranial • smaller than most A. afarensis, but larger than AL-288-1; humeral head 30% larger

• elliptical humeral head• blunt, proximally extened ulnar olecranon

process w/ a straight dorsal upper shaft profile

• anteriorly oriented trochlear notch• anteriorly facing ulnar brachialis insertion

• strong angulation of distal radial articular surface, large styloid process

• strong lateral trochlear ridge on the distal humerus• elongate superposteriorly extended lateral humeral epicondyledentition• some dental chars more similar to chimp than any known hominid• deciduous molar very small (sig below the A. afarensis avg, on low end of chimp range,

comparable to bonobo)• size of upper and lower central incisors relative to postcanines comparable to Miocene

hominids & gorillas• morphology of canines differ from known apes• canine enamel thickness similar to chimp but lacks apical thickening

• upper & lower canines larger relative to postcanines• absolute & rel thinner enamel• shape of 1st deciduous molar; lower 3rd molar more strongly assym;

upper 3rd molar more assym• no anterior fovea and small, low taloned w/ minimal cupsule

developmentupper central incisors

• canine morphology more incisorform• relatively higher crown shoulders; crowns less projecting• cupped distal wear pattern on lower canine• smaller mandible P3, different shape• no honing facet/different wear pattern

differ from

Miocene & living apes {differ from

australopithecines{

} like modern apes

} shared with hominins

K E Y S P E C I M E N S

• ARA-VP-6/1: (juvenile) 10 teeth from 1 indiv

• ARA-VP-6/500 “Ardi”: 45% of her skeleton (including most of the skull, pelvis, hands and feet, many limb bones).

Estimated height 120cm (3'11") tall; weight aprox 50 kg (110 lbs)

300-350cm3 cranial capacity

• ARA-VP-7/2 consists of parts of all 3 bones from the left arm of a single individual

M A J O R S I T E S• Aramis, Ethiopia: headwaters of drainages;

all specimens surface finds

B I B L I O G R A P H Y

Cerling, T. et al (2010) Comment on the Paleoenvironment of Ardipithecus ramidus, Science 328 (5982): 1105

Gibbons, A. (2009) A new kind of ancestor: Ardipithecus unveiled, Nature 326: 36-40.

Haile-selassie, Y. et al (2001) Late Miocene hominids from the Middle Awash, Ethiopia, Nature 412:178-181.

Harrison, T. (2010) Apes Among the Tangled Branches of Human Origins, Science 327 (5965): 532-534

Louchart, A. et al (2009) Taphonomic, Avian, and Small-Vertebrate Indicators of Ardipithecus ramidus Habitat, Science 326 (5949): 66-66e4

Lovejoy, C. (2009) Careful Climbing in the Miocene: The Forelimbs of Ardipithecus ramidus and Humans Are Primitive, Science 326 (5949):70-78

Lovejoy, C. (2009) The Pelvis and Femur of Ardipithecus ramidus: The Emergence of Upright Walking, Science 326 (5949): 71-76

Lovejoy, C. (2009) Combining Prehension and Propulsion: The Foot of Ardipithecus ramidus, Science 326 (5949): 72-78

Lovejoy, C. et al (2009) The Great Divides: Ardipithecus ramidus Reveals the Postcrania of Our Last Common Ancestors with African Apes, Science 326 (5949):73-106

Lovejoy, C. (2009) Reexamining Human Origins in Light of Ardipithecus ramidus, Science 326 no. 5949 pp. 74-74e8

Sarmiento, E. (2010) Comment on the Paleobiology and Classification of Ardipithecus ramidus, Science 328 (5982): 1105

Suwa, G. et al (2009) The Ardipithecus ramidus skull and its implications for hominid origins, Science 326(5949): 68e1-68e7.

Suwa, G. et al (2009) Paleobiological Implications of the Ardipithecus ramidus: Dentition, Science 326(5949): 69-99.

White, T. et al (1994) Australopithecus ramidus, a new species of early hominid from Aramis, Ethiopia, Nature 371:306-12.

White, T. D., et al (2009) Ardipithecus ramidus and the Paleobiology of Early Hominids, Science 326(5949):64-64, 75-86.

White, T. D. et al (2009) Macrovertebrate Paleontology and the Pliocene Habitat of Ardipithecus ramidus, Science 326(5949): 67-93

White, T. D. et al (2010) Response to Comment on the Paleobiology and Classification of Ardipithecus ramidus, Science 328 (5982): 1105

WoldeGabriel, G. et al (2009) The Geological, Isotopic, Botanical, Invertebrate, and Lower Vertebrate Surroundings of Ardipithecus ramidus, Science 326 (5949): 65-65e5