Quiz 3 Fossil Hominins (10 hominins) Part 3

Habilis fossil remains are sometimes also associated with tool manufacture and use. Which early tool-complex are we talking about?

"Oldowan" tool complex

Australopithecus afarensis (Retained "primitive" characteristics)

*afarensis species = is still quite short *phalanges are still curved, like the similar phalanges of Ardipithecus ramidus. (Note curved phalanges are like arboreal adaptation found in apes such as the gibbon) *afarensis was a hybrid form that had the curvature of the ape phalanges, but more human-like "shortening" of phalanges bones

Australopithecus ghari (Non-anatomical aka "cultural" traits) (2 total "cultural" traits)

*ghari specimens are found associated within their depositional levels or strata with mammalian bones showing signs of cut marks; implies the use of tools by ghari -No tools have been found at Bouri; only the evidence of such tool use represented by the cut marks upon mammalian bones *another archaeological site named Gona, only 30 km distance, have discovered actual "Oldowan" tool (recall "chopper type" tool). The actual Gona tools date to approx 2.6 mya, which is approx. the same time-frame as the dates of the neighboring Australopithecus ghari specimen found at the Bouri site

Ardipithecus ramidus (Retained "primitive" characteristics) (9 total "primitive" characteristics)

*ramidus species = still quite short *dental enamel not as thick as it is in other hominins (somewhat like an ape's "thin enamel" cond) *mandibular canine still rather lengthy *mandibular P3 still partly "sectorial" *adaptations in lower pelvis that facilitates climbing behaviors *retention of extremely long forelimbs (arms)(not unlike a gibbons forelimb) *retention of an "opposable" (divergent) big toe *retention of long, curved phalanges, on both "hands" and "feet" (also like the gibbon)

Sahelanthropus tchadensis (3 total Characteristics)

- 1 of 2 Pre-Australopithecines -Found: site of Toros-Menalla; Chad, North Africa -Date: 6-7 mya -Characterisics: *braincase small (350cc) *foramen magnum beneath the vault of the cranium *trait indicates probable bipedalism

Australopithecus afarensis (9 total Characteristics)

- 1 of 5 Australopithecines -Found: "Afar depression" of Northern Ethiopia, specifically site of Hadar -"Lucy" specimen -Date: 3.2 mya -Characterisics: *braincase small (430cc) *based upon recovered pelvic bones from "Lucy" skeleton; pelvic girdle was definitely shorter and wider than the pelvis of an ape (indic bipedalism) *the angle of femur, appears to have inward slant on its lower or distal end. Indicates "valgus" knee was present. (indic bipedalism) *Adult male recovered; distal femur connected to the proximal(upper) tibia. This connection site definitely reveals presence of a "valgus" knee. (indic bipedalism) *Adult male fossil; of a rather complete scapula (shoulder); scapula is quite similar to the scapula of a modern human, with its characteristically upright, bipedal torso. *footprings found associated with afarensis fossil at the site of Laetoli, Tanzania, reveal that these individuals walked bipedally, with both transverse and longitudinal arches, and had lost the opposable (divergent) big toe. --"afarensis": canines are smaller than that of earlier species' (=loss of the CP3 complex) --the mandibular P3(premolar) has lost any sectorial quality; the two premolar cusp are rather equal in size (=loss of the CP3 complex) --the upper (maxillary) dental arcade is very nearly "parabolic" in shape, rather than "U-shaped" as in the apes. (The parabolic dentition is indicative of recent Homo genus hominins, and mod. Humans)

Ardipithecus ramidus (8 total Characteristics)

- 2 of 2 Pre-Australopithecines -Found: at Aramis, the "Afar Depression"; North Ethiopia (East Africa "Rift Valley") -Date: 4.4 mya -Characterisics: *braincase small (350cc) *foreshortened and wide pelvic structure (indic bipedalism) *angle of femur; existence of valgus knee(knee angled outward) *rigidification of foot bones(helps propel body fwd bipedalism) *shortened and non-lengthy upper or maxillary canines(loss of CP3 complex) *no honing on backs of canines or on front of the P3(loss of CP3 complex) *abrasive wear only on tips of canines *dental enamel in molars not as thin as ape, but not as thick as humans = in other words hybrid

Australopithecus ghari (3 total Characteristics)

- 2 of 5 Australopithecines -Found: Bouri site, in Middle Awash region of "Northern Ethiopia" -Date: 2.5 mya -Characterisics: *Braincase is still small (450cc) *Only Australopithecine in which the ratio of the femur bone to the humerus bone is similar to that of current humans. This means the femur in the ghari species has lengthened. (one of the characteristics. indicate ghazi was ancestral to subsequent Homo genus) *Paleoanthropologist's have noted that several characteristics of ghari's dentition also align it with subsequent hominins; dental trait is the shape of ghari's P3: this premolar shows two very distinct cusps, and is consequently non-sectional

Australopithecus africanus (5 total Characteristics)

- 3 of 5 Australopithecines -Found: scattered at sites in South Africa; ex: Swartkran; Sterkfontein; Makapansgat -"Gracile" (graceful skull) -Date: 3-2 mya -Characterisics: *Braincase is still small (450cc) *dentition may be characterized as being composed of moderate-sized teeth. (= loss of the CP3 complex) *"africanus" mandibular premolar (P3) shows equal-sized cusp. (= loss of the CP3 complex) * upper or maxillary dentition shows a very parabolic shape, rather than the "U-shaped" dentition of apes *phalanges bones not curved --Note: africanus hominid is generally referred as "gracile Australopithecine"

Australopithecus robustus (4 total Characteristics)

- 4 of 5 Australopithecines -Found: sites throughout South Africa; ex: Swartkrans; kromdrei -"robust" (massive mandible; massive rear teeth; flat molars for grinding; sagittal crest) -Date: 2.3-1.2 mya (extinct) -Characterisics: *Braincase comparatively small (530cc) *Only skulls and teeth discovered *massive posterior teeth (both premolars and molars) with non heightened cusps *no visible sign of a CP3 complex (canine in both maxillary and mandible dental arcade is smallish and non-protruding) *no visible sign of mandibular diastema *a visible "sagittal crest" running across the top of the cranium; this feature associated with heavy chewing (just like orangutans and gorillas); comprises the attachment location for a massive mandibular musculature *these "robust" Australopithecines usually thought to have concentrated on chewing/grinding thick or coarse grasses or vegetative material; they appear to have been specialized "grinders." The association loss of the CP3 complex would facilitate side to side grinding activity; non heightened cusps throughout the dentition would have facilitated grinding function

Australopithecus boisei (3 total Characteristics)

- 5 of 5 Australopithecines -Found: East Africa; both near lake Turkana, Kenya; Olduvai Gorge in North Tanzania in 1959 -"Robust Australopithecines" (mandible are so impressive; loss of the CP3 complex; sagittal crest) aka "Paranthropines" (massive molars) -Date: 2.3-1.2 mya -Characterisics: *braincase smallish (530cc) *massive posterior teeth, nearly identical to the dentition of the robust Australopithecines of South Africa *loss of the CP3 complex; reduction in size and overhang of the canines; loss of the mandibular diastema, etc *evidence of a sagittal crest running atop the cranium from from to back, with the implication of a grinding functionality

Homo habilis (2 total Characteristics)

-1 of 3 Homo genus -Found: Olduvai Gorge by Louis Leakey -"Homo" genus is the larger brain -Date: 2.5-1.9 mya -Characterisics: *Homo habilis generally has larger brain braincase (750cc) *But this is the only Homo genus species that Is still relatively short in stature (height)

Homo erectus (# total Characteristics)

-2 of 3 Homo genus -Found: species found around the "old world" locations such as: China, (Java, Indoneisa), Africa, and numerous locations in Europe -"Homo" genus is the larger brain -Date: 1.8 mya-400,000 yba -Characterisics: *the cranial capacity of H.erectus has increased substantially with certain specimens having a cranial capacity of 900-1000cc (this also reflects an attendant increase in brain size, as well as presumed intellect) *H. erectus is the first hominin (with the possible exception of A. ghari) to have been taller than all earlier hominins. It reached the full height of subsequent modern humans. (the latter trait seems to been integral to the migratory spread of the H. erectus species out of Africa, and around the "old world") *the dentition of erectus is diminished in size from that of the Australopithecines. This reduction is thought to have been attributable to change in the diet away from coarse, fibrous vegetative materials (robust Australopithecine relied upon); accompanied by an addition of meat in the erectus diet, acquired through scavenging or hunting *Also, the diminution in the size of the dentition (particularly the front dentition) seems associated with the apparent use of Acheulean tool technologies (erectus manufactured and used this more challenging, sophisticated bifacial technology) *H. erectus individuals almost always have large, very pronounced brow ridges, as well as quite thick cranial bones. (The latter characteristic tends to be present in all specimens recovered) whether from central China, Europe, or even island of Java, Indonesia *there is no sign of a sagittal crest, but some of the specimens show signs of what is called a "sagittal keel" (a slight rise in the bone near the front-to-back crest of the cranium)

Homo sapien (# total Characteristics)

-3 of 3 Homo genus -"Homo" genus is the larger brain aka "wise man" (latin) -Date: 27,000-23,000 ybp -Characterisics: "Anatomically-Modern Humans"

What are the distinctive erectus anatomical characteristics, and how do these traits prove an even more direct link between erectus and the subsequent rise of Homo sapiens?

-Bigger cranial capacity (900-1000cc) -reached the full height of subsequent modern humans -dentition of erectus is diminished in size form that of the Australopithecines -pronounced brow ridges; quite thick cranial bones -no sign of sagittal crest

Homo erectus. -found in which regions of the world? --dating generally to what time-frame?

-Date: 1.8 mya - 400,000 ybp -Found: Homo erectus species = found around "old world"; China, (Java, Indonesia), Africa, and Europe

What was the probable diet of the robust australopithecines? --and why do we know this?

-Diet consisted of vegetative material; chewing thick or coarse grasses -why we know = dentition massive posterior teeth flatted molars from grinding

Australopithecus boisei. -found in which region of Africa? -Dates to approx. when? -Characteristic cranial and dental morphologies? --associated with what kind of diet?

-Found: near Lake Turkana, Kenya (East Africa) and Olduvai Gorge (North Tanzania) in 1959 -Date: 2.3-1.2 mya -massive posterior teeth -loss of the CP3 complex; reduction in size of overhang of the canines; loss of mandibular diastema -evidence of a sagittal crest -"robust" Australopithecine have vegetative diets; heavy chewing/ grinding thick coarse grasses

Who were more or less scavengers?

-Homo habilis -Homo erectus

What is the primary "advanced hominin" characteristic possessed by Homo habilis? --In what general part of Africa have most habilis specimens been found? --what is the cranial capacity of the habilis skull, when compared to the australopithecines?

-Homo habilis has larger brain -Found: in Olduvai Gorge (East Africa) by Louis Leakey -Cranial Braincase (750cc) compared to Australopithecine braincase (430cc, 450cc x2, 530cc, 510cc)

Were the later australopithecines (i.e., the more recent Australopithecines) in the direct line of hominin evolution, or not? --i.e., did they contribute to the appearance of Homo sapiens? What probably happened to the later (the more recent) australopithecines?

-No, the later Australopithecines are not in direct line of hominin evolution. They did not contribute to the appearance of homo sapiens. -The later Australopithecines eventually became extinct about 1.2 mya A.robustus A.boisei

Understand Owen Lovejoy's "Provisioning hypothesis," and how the latter might account for the rise of bipedalism in ancestral hominin populations. -do you understand the ways that Lovejoy's scenario actually accounts both for the rise of bipedalism, and also for the loss of the Canine-Premolar Honing complex in hominins? (Refer to the 2-page handout I sent you by email; also, how is this loss of the honing complex related to the apparent lack of sexual dimorphism [dimorphism = a dramatic diff. in size of males and females] in fossil hominins?)

1) sexual selection played a role in canine reduction; did not have to compete and fight for fertile females 2) suggests that females preferred nonaggressive males who gained reproductive success by obtaining copulation in exchange for valuable food (vested provision) 3)Dimorphism = means male and female canines were not only similar in size but the male canine had been dramatically "feminized" in shape

What are the two anatomical (skeletal) trait-complexes which primarily distinguish the hominins from the hominoids (in other words, which distinguish humans and their fossil ancestors [the hominins], from the apes and their fossil ancestors [the hominoids])?

1)Bipedalism 2)loss of the canine "honing" complex (CP3 complex)

What are the various anatomical characteristics associated with the Canine-Premolar Honing complex (C/P3 complex)? --or, alternatively, with the loss of Canine-Premolar honing? (4 total attributes to C/P3)

1)Overhanging/ protruding canines 2)Mandibular diastema 3)"honing" wear pattern -you will find honing abrasion -full length of back of canine 4)Sectorial P3 (pointer at top)

What are the various anatomical characteristics associated (in some form) with bipedalism? (Note: these may be either cranial characteristics, or post-cranial characteristics.) (7 total Physical Characteristics associated with Bipedalism)

1)foramen magnum location 2)"S-shaped vertebral column" 3)Pelvic is wider, bowl shaped girdle 4)Angle of femur "inwards" 5)"Valgus" knee (inward knee) 6/7) Rigidification of foot bones 6) loss of the opposable big toe (halux aka big toe) 7) development of arches a)transverse arch (side to side) b) longitudinal arch (front to back)

Approximate time-span, in years-before-present, during which the Acheulean lithic complex was extant?

1.8 mya is time "Acheulean" tools were extant -used by Homo genus specifically Homo erectus

Approximate time-span, in years-before-present, during which the Oldowan lithic complex was extant?

3.3 mya is the time "Oldowan" tools were extant -used by Australopithecine specifically Australopithecine afarensis "Lucy"

Which of the australopithecines, if any, seems MOST likely to have been the ancestor of at least some of the "Homo" hominins? -and WHY? (HINT: this assessment is based upon a rather unique [for the australopithecines] post-cranial characteristic.)

Australopithecine afarensis -scapula is quite similar to the scapula of modern human -maxillary dental arcade is very nearly "parabolic" in shape indicative of recent homo genus, and mod humans

Most famous Australopithecus and earliest tool used "Oldowan" tools 3.3 mya

Australopithecines genus used -Australopithecines afarensis tool called = "Oldowan Chopper" or "Oldowan Polyhedron"

Oldowan tools associated with which fossil hominins?

Australopithecus afarensis "Lucy"

"Lucy" --genus and species? --dates to when?

Australopithecus afarensis "Lucy" Date: 3.2 mya

Time-frame for the australopithecines (living, generally, from which years, to which years)?

Date: 4 mya - 2.6 mya (Dr. Michael Timeline) or 4mya - 2.5 mya (Handout)

What is perhaps most significant about the Homo erectus finds at Zhoukoudien cave, China? (Think in terms of one of our most important cultural achievements.)

Fire use found in the caves

Australopithecus afarensis. Characteristics (identify three post-cranial characteristics, and three cranial or dental characteristics) that identify it as definitely in the hominin line? Does afarensis have any characteristics that might be considered "primitive," and thus indicative of an intermediary status between apes and hominins? (7 important characteristics) (2 total "primitive" characteristics)

Found: Afar depression of Northern Ethiopia, (East Africa)site of Hadar Date: 3.2 mya Characteristics: *"Lucy" *pelvic girdle was definitely shorter and wider *a "valgus" knee *Adult male also recovered; this connection site definitely reveals presence of a "valgus" knee *Adult male fossil; a complete scapula (shoulder blade bone) similar to the scapula of a modern human, *both transverse and longitudinal arches, and had lost the opposable (divergent) big toe *canines are smaller (=loss of the CP3 complex) *two premolar cusps are rather equal (=loss of the CP3 complex) *maxillary dental arcade is very nearly "parabolic" in shape; (parabolic dentition is indicative of recent homo genus and mod humans) Retained "primitive" characteristics: *afarensis as a species, is still quite short *phalanges are still curved, like the similar phalanges of Ardipithecus ramidus

Ardipithecus ramidus. Fossils date to when? Characteristics (identify two or three) seeming to point to its inclusion within the early hominin line? Does it retain any primitive characteristics (that would consequently place it as an intermediary form between the ape line and the hominin line)? (7 important characteristics) (5 total "primitive" characteristics)

Found: at Aramis, "Afar Depression" Northern Ethiopia (East African "Rift Valley" Date: 4.4 mya Characteristics: *braincase small (350cc) *foreshortened and wide pelvic structure (indic bipedalism) *angle of femur; existence of valgus knee(knee angled outward) *rigidification of foot bones(helps propel body fwd bipedalism) *shortened and non-lengthy upper or maxillary canines(loss of CP3 complex) *no honing on backs of canines or on front of the P3(loss of CP3 complex) *abrasive wear only on tips of canines *dental enamel in molars not as thin as ape, but not as thick as humans = in other words hybrid Retained "primitive" characteristics: *ramidus as species quite short *P3 still partly "sectorial" *extremely long forelimbs *retention of an "opposable" (divergent) big toe *retention of long, curved phalanges (hands and feet)

Australopithecus ghari. Characteristics placing ghari in the hominin line? --ghari dates to when? --What is the one post-cranial, anatomical characteristic that most distinctively and conclusively places garhi in the hominin line, and possibly immediately ancestral to many Homo-genus hominins? Are there any possible "cultural" characteristics that also potentially delimit garhi as an ancestor of the more advanced "Homo" hominins? (1 important characteristics) (1 "cultural" characteristics)

Found: recovered at the Bouri site; in the Middle Awash region of Northern Ethiopia, (East Africa) Date: 2.5 mya Characteristics: * the femur in the ghari species has lengthened; this is one characteristic that seems to indicate that ghari was ancestral to subsequent Homo genus Non-anatomical; "cultural traits": *archaeological site named Gona, discovered actual "Oldowan" tools, the Gona tools date to approx 2.6 mya same as ghari; tool usage shows ancestor of more advanced "Homo" hominins

Australopithecus africanus and Australopithecus robustus. These species found inwhich region of Africa? (For instance: --east Africa? -south Africa? -west Africa?) --Dating approx.

Found: site found in South Africa and throughout South Africa -Australopithecus africanus (ex: Swartkrans; Sterkfontein, Makapansgat) -Australopithecus robustus(ex: Swartkrans; kromdrei) Date: -Australopithecus africanus (3-2 mya) -Australopithecus robustus (2-1.5 mya)

Sahelanthropus tschadensis. Fossils found where? Dating approx. to when? Characteristics (identify one) seeming to conclusively point to its inclusion within the early hominin line? (1 important characteristics)

Found: site of Toros-Menalla Chad, (North Africa) only one found outside of "Rift Valley" Date: 6-7 mya Characteristics: *braincase small (350cc) *foramen magnum beneath the vault of the cranium

Important traits with Homo genus

Homo = bigger brain Homo erectus = taller in height; larger body

Acheulean tools associated with which fossil hominins?

Homo erectus

Are the erectus finds ever associated with tool assemblages? --If so, which tool complex are we talking about?

Homo genus used -specifically = hand axes found by Homo erectus "Acheulean" tool -tools manufactured by Homo erectus

1st species to leave Africa?

Homo species

Tools found at Gona (within 30km of the ghari finds): are they Oldowan or Acheulean?

Oldowan tools are found 30km distant site name: Gona

Another name for "Oldowan" tools?("Oldowan Chopper" and "Oldowan Polyhedron")

Pebble tools; pebble chopper;

Why do we think these tools may have been manufactured by garhi?

The actual Gona tools date to approx. 2.6 mya which is the same dates for this Genus-species "Australopithecus ghari" date: 2.5 mya

What is the significance of thin enamel, vs. thick enamel? (Thin enamel results primarily from what dietary environment? --and is associated with which species of hominoid? [notice I said hominoid, meaning ape].) --what about thick enamel? (What type of diet? ...and which species of hominoid?) (HINT: look back at your lecture notes)

Thin enamel = results in diet of softer and less abrasive foods such as arboreal ripe fruits Associated w/ Ardipithecus ramidus Thick enamel = due to sagittal crest; heavy chewing function; chewing/grinding thick or coarse grasses/ hard fruits Associated w/ 1)Australopithecus robustus 2)Australopithecus boisei

Does habilis nonetheless retain something of a "primitive" post-cranial characteristic? Please identify that characteristic.

Yes! Homo habilis = is still relatively short in stature

Understand Darwin's "Hunting hypothesis." --Be certain you understand the comparative dates of: a)the first appearance of bipedalism in hominins, and: b)the onset of tool manufacture in hominins; --what does this comparison tell us about the validity (or the lack of validity) of Darwin's hunting hypothesis?

a) the first appearance of bipedalism in hominins was with Ardipithecus ramidus roughly 4.4 mya b) the first set of tool manufacture in hominins was roughly 3.3 mya used by Australopithecus afarensis "Lucy" c)Some hominins were still arboreal and did not use and carry weapons. it is now known that bipedalism occurred long before brain size increase and the first stone tools. Darwin "Hunting Hypothesis" suggests that hominids were bipedal because it freed their hands to carry weapons. He believed that their greater intelligence due to large brains enabled them to make and use tools. This is false

General characteristics of the australopithecine line of early hominins?

bigger brains and taller

Briefly describe the habilis dental complex, in terms of how it differs from australopithecines.

dentition of habilis; the chewing muscles and teeth of Homo habilis are smaller than the australopithecines (bigger molars) Homo habilis had a more generalized diet than the australopithecines, many of which specialized on a narrow range of foods. different diet

Rift Valley-- location and significance?

located Northern Ethiopia; significance is that it is the "cradle of mankind" 9 of 10 the fossil hominins found here: Ardipithecus ramidus Northern Ethiopia (East Africa) "Rift Valley" Australopithecus afarensis Northern Ethiopia (East Africa) A.ghari Northern Ethiopia (East Africa) A.africanus South Africa (ex: Skwathkran, Sterkfontein, Makapansgat) A.robustus South Africa (ex: Skwathkran, Kromdrei) A.boisei Olduvai Gorge in 1959 (East Africa) Homo habilis Olduvai Gorge (East Africa) H.erectus "Old World" China, Java.Indonesia, Africa, and Europe H.sapien The only outlier is Sahelanthropus tschandensis which the only one found outside the "rift valley" Chad, Central Africa

Name and describe the various selection pressures responsible for the emergence of the Canine-Premolar Honing (C/P3) complex. Were certain of these selection pressures more important in the development of this complex within certain species, than in others? --Name some examples. (For instance, think of the differing social habitats, and differing selection pressures, that were involved in selecting-for the C/P3complex within certain monkey species [like baboons], versus within certain ape species [like chimpanzees & gorillas].)

selection pressure Baboon = living on the savannah fighting off predators selection pressure Gorilla = fighting w/ other males for fertile female "large canines" selection pressure chimpanzee = omnivore diet ate meat attacking other monkeys for food;