ANTH 1101 - Chapter 10

From Hominoid to Hominin:

• We walk on two legs (__ __)

• We have small __ and large __ with thick __

• We have very large __

• We have much slower __ __ and a long __ __

• We have complex language, technology, and symbolic culture

obligate bipedalism
canines, molars, enamel
brains
life histories, juvenile period

Bipedality: Skull, Spine, and Pelvis:

• Skull

  • Foramen magnum position

    • The __ that the __ enters

    • This sits right at the __ of the __

      • For humans (bipedal) it’s below the __ of the skull

      • For other primates (quadrupedal), it’s __ the skull because of the way they walk

• Lumbar lordosis

  • The natural, healthy inward __-shaped __ of the lower back (lumbar spine

• Pelvis

  • __ and __ in bipeds

  • __, __ pelvis in quadrupeds

    • Chimpanzees and other apes

• Femur

  • __ femoral neck

  • Cortical bone distribution

    • Cortical bone is __ in quadrupeds

  • Muscles in the hips contract at the same time as we walk so we don’t wobble as our body balances on walking (as when we walk, we lift one leg at a time)

    • Increases the level of muscle efficiency

  • In quadrupedal animals, head of the femur is __, and __ in humans (bipeds)

hole, spine
dome, skull
bulk
behind
C, curve
Short, stout
Tall, thin
Long
thicker
shorter, longer

Bipedality: Knee, Foot, and Ankle:

• Knee

  • Bicondylar angle

    • Humans are not __ with a bicondylar angle

      • If you never __, you will never develop this

  • Foot and ankle

    • __-__ big toe

      • We no longer have this, it suggests a move away from __ ability

    • Arches

born, walk
Nongrasping
climbing

7-5 Ma… The First Bipeds (?):

• Sahelanthropus tchadensis

  • __, Africa 

  • Dated to __-__ Ma 

    • Foramen magnum suggests __

    • __-sized brain (small)

    • Small __

    • __ face; large __

Hominin?

Chad
7–6
bipedality 
Chimpanzee
canines 
Flat, browridge

7-5 Ma… The First Bipeds (?):

• Orrorin tugenensis

  • __, Africa

  • Dated to __ Ma 

    • Mix of __ and __

    • Femur suggests __

      • Suggests that orrorin was bipedal

    • Teeth __-like, but __ enamel 

Hominin?

Kenya
6
woodland, savanna 
bipedality 
chimpanzee, thicker

7-5 Ma… The First Bipeds (?):

• Ardipithecus kadabba 

  • __, Africa 

  • Dated to __-__ Ma 

    • Toe bone suggests __

    • Canine __ against lower __

    • Aka ‘C/P3 honing complex

Hominin?

Ethiopia
5.8–5.2
bipedality 
sharpens, premolar 

7-5 Ma… The First Bipeds (?):

• Ardipithecus ramidus

  • __, Africa 

  • Dated to __ Ma 

  • __ habitat 

    • Bipedal based on __, __, and __

    • __ based on hand, foot, and pelvis 

    • Smaller __

    • Small __

      • Suggesting a lower level of __ __

Hominin?

Ethiopia
4.4
Woodland
skull, pelvis, foot 
Climbing
brain 
canines
sexual dimorphism

Why Bipedalism?:

• __ adaptation

  • Arboreal bipedalism

  • Ground feeling

• __

  • Bipedalism saves energy

• __

  • Less solar radiation

    • Wouldn’t get as hot in climate that was starting to become warmer

• __ and provisioning

Feeding
Energetics
Thermoregulation
Carrying

Genus: Australopithecus:

• Means ‘__ __’

• Multiple species 

• Spanned __-__ Ma

• Occupied __, __ and __ __ 

• ‘Gracile australopiths’ 

  • Less __ craniodental features 

• Variable combinations of traits

  • Small __

  • __

  • Smaller __

  • Large __

Southern ape
4-1.9
East, Central, Southern Africa
heavy
brained 
Bipedal 
canines 
molars

Australopithecus anamensis:

• __ and __ 

• Dated to __-__ Ma 

• Environment: __ __

• __

  • Tibia 

• Retained __ abilities 

  • Long __, curved __

• Canines __ than modern apes 

• “__ face” (__)

  • A bit snouty but below the nose

Kenya, Ethiopia 
4.2–3.9
grassy woodland 
Bipedal 
arboreal
arms, fingers 
smaller
Jutting, prognathism

Australopithecus afarensis:

• __ and __ 

• Dated to __-__ Ma 

• Environment: __ __

• Smaller __, larger __ than Au. anamensis 

• __

• ~450 cc cranial capacity 

• Small __, but __

• Partial skeleton: Lucy

Ethiopia, Tanzania 
3.6–3.0
woody grassland 
canines, molars
Bipedal  
bodied, dimorphism 

Australopithecus afarensis:

• “Dikika child” (DIK-1-1) 

  • aka Selam (meaning ‘peace’) 

  • Dikika, __

  • Dated to __ Ma 

  • Three-year-old female 

  • __; tree climbing? 

  • Hyoid 

    • Tiny __ in the __ that is part of our ability to __

    • Very important in understanding the ability to speak

  • Slower __ __

** Juvenile skeletal remains help us understand hominin __ and __ 

Ethiopia 
3.3
Bipedal
bone, neck, speak
brain maturation 
growth, development

Australopithecus afarensis:

• Clearly __

  • Based on __, __, __, __, __

  • Laetoli footprints 

• Some retained __

  • Based on scapula, __

bipedal 
spine, pelvis, knee, ankle, foot 
arboreality 
fingers

Australopithecus garhi:

• __ __

• Dated to __ Ma

• Cranium

  • Small __ (450 cc)

  • __ __

  • Large __

• Postcrania: __ __

  • Long, strong __

• Stone tool?

East Africa
2.5
brain
Sagittal crest
teeth
longer legs
arms

Australopithecus africanus:

• __ __ (primarily from __ __)

• Dated to __-__ Ma

• Environment: __ __

• Anatomy:

  • Rounder __, slightly larger __

  • Smaller __*

  • __ face

  • Long __

  • Pelvis, femur indicate __

  • Shoulders and arms suggest retained __

  • __ __

* Compared to Au. afarensis

South Africa, cave deposits
3.3 - 2.1
woody grassland
skull, brain
teeth
Prognathic
arms
bipedality
arboreality
Sexually dimorphic

Australopithecus africanus:

Taung Child

• ~3 year old infant

• Skull, jaw and endocast

• Foramen magnum = __

• Small __

• Type specimen for Au. africanus

* Challenged idea that humanity originated in Europe or Asia

* Challenged idea that large brain preceded upright walking 

bipedal
canines

Australopithecus sediba:

• __ __

  • Malapa Cave, Cradle of Humankind

• Dated to __ Ma

• Environment: __ and __

• last of the gracile australopiths (?)

• Anatomy:

  • Small __, small __

  • Reduced musculature for __

  • Less pronounced __, __ __, and __

South Africa
1.98
woodland, savannah
brain, teeth
chewing
browridge, cheek bones, prognathism

Australopithecus Shared Characteristics:

• Diastema = __ between __ __ __ and __ __

• Reduced __

• Large __, strong __

• Brain size intermediate between chimp and humans

gap, upper lateral incisor, canine teeth
canines
jaws, cheekbones

Australopithecus Shared Characteristics:

• __

• __-shaped spine

• Retained __ adaptations

Bipedal
S
arboreal

Genus: Paranthropus:

• AKA “__ __”

• Multiple species

• Spanned __-__ Ma

• __ and __ Africa

• ‘__’ features

  • Enormous __

  • Big __ __

  • __ __

  • Huge __ __ (zygomatic arches)

  * Adaptations for eating __ foods (__ and nuts)

• Bipedal 

robust australopiths
2.6-1.2
East, Southern
Robust
molars
chewing muscles
Sagittal crests
cheek bones
hard, roots

Paranthropus aethipicus:

• __ and __

• Dated to __-__ Ma

• ‘__ Skull’

  • From staying in __ rich soil

  • Strong __

  • __, __ zygomatics

  • Medagont

  • __ __

Kenya, Ethiopia
2.7 - 2.3
Black
magnesium
prognathism
Wide, flaring
Sagittal crest

Paranthropus boisei:

• __ Africa (Ethiopia, Kenya, Tanzania, Malawi)

• Dated to __-__ Ma

• Hyper __

• Type specimen: ‘Zinj’ or ‘Nutcracker Man’

• Has the __ teeth of __

East
2.2 - 1.3
robust
thickest, hominins

Paranthropus robustus:

• __ Africa

• Dated to __-__ Ma

• __ and __ adaptations for heavy __

• Bipedal extended growth in males?

South
1.8 - 1.0
Cranial, dental, chewing

‘Gracile’ vs ‘Robust’ Australopiths:

• Gracile australopiths come from the __ genus

• Robust australopiths come from the __ genus

• Know some of the differences between the two

Australopithecus
Paranthropus

Kenyanthropus platyops:

• __

• Dated __-__ Ma

• Cranial

  • Small __

  • **__face

  • Small __

  • Post cranial: nothing yet

  • Alternative to australopithecus?

Kenya
3.5 - 3.2
brain
Flat
molars

• Obligate bipedality: 

  • __ are the only primates that are able to do this exclusively

Humans

• Prognathism: the __ of the __

  • The lower part of the face tends to jut out, in other non-hominin species is very jutty

    • For humans its a bit more __ as the lower part of our face is __

protrusion, jaw
inward, smaller

• Sahelanthropus tchadensis

  • Demonstrates that as we get closer, the lines become __, more difficult to determine which __ is which

  • A candidate for the first true __

    • But most people believed that the first ancestors were found in the __, challenging that idea

blurred, lineage
hominin
East

• Know where these species were from, need to know that date (ex: one of the earliest species), what anatomy we base the assumption of 

…

• Orrorin tugenensis

  • Some people argue that skeletal bipedality does not necessarily mean __ bipedality

  • Orrorin Tugenensis = Tugenensis - was found in the __ __

obligate
tugen hills

• Honing complex: the teeth __ against each other

sharpen

• Postcranial = below the neck/skull

…

• Some think that bipedality is more efficient especially in long distances

…

• Upright walking developed before encephalization (enlargement) of the brain

…

• Mosaic anatomy:

  • Used a lot in early hominin taxonomy because each group has a unique combination of ancestral and derived characteristics

…

• Australopithecus Afarensis best represented

  • Most common/very discovered

…

• Earliest primate → Pleisadapiforms

  • “Stem primate” because they only exhibit some, not all primate characteristics

  • Evolved in North America

  • Are primate like

…

• Earliest ‘ape’ → Proconsol (Genus)

…

• Earliest hominins

  • Sahelanthropus tchadensis

    • Lived somewhere around __ mya

    • From __ __

  • Orrorin tugenensis

    • From East Africa

7
Central Africa

• Hominin: All of those organisms that are more closely related to us than Pan

  • Bipedal 

…

• What is the earliest member

  • Think of is it an early primate, ape, hominin, mammal 

…

• Genus → Australopithecus anamensis (formal genus name)

  • Also known as “gracile australopiths” (informal name)

…

• Gracile: __ __ (referring to the skull)

lightly built

• Australopithecus anamensis are also one of the early hominins

…

• “Missing link” is not true nor relevant

…

• Paranthropus is a hominin but not thought to be a direct ancestor of humans, more like  a cousin

…

• Type specimen: the exemplar (blueprint) of a species

…