EXAM 3 BIO ANTHRO

Raymond Dart

Was a PhD student
was in Taung South Africa

Taung Child

New species Australopithecus africanus

Australopithecus Africanus

Taung Child

What two things did Dart Claim about the juvenile Australopithecus africanus from Taung

1. endocast was more human than Ape like
2. Foramen Magnum was placed forward- evidence for bipedalism?

"The position of man's foramen magnum diff greatly from animals...since man has his body and neck directed vertically, his head must be placed inbalance on the vertebral column"

Daubenton- 1764

What was the basic idea?

1. Bipeds need to balance their heads atop an upright torso 2. Quadrupeds do not

What did Dart claim?

Australopithecus africanus is a biped and is a very early fossil relative of humans

What was the reaction of the scientific community to this claim?

- Who is this crazy Australian anyways?
- Taung Child is a young fossil chimpanzee

What were the reasons behind these negative reactions?

-Racism
-Brain before bipedalism claim
-Piltdown man

The search for the missing link

origin of species 1859 and the descent of man 1871

Mauer Mandible

found in 1907 in a sand quarry near Heidelberg
-600 KYA
It is big and robust but has no chin, unlike humans

Pitdown Gravel Pit

Sussex, England in 1912
Charles Dawson, Sir Arthur, Smith Woodward found the Piltdown man- named
eoanthropus dawsoni

Piltdown man

Eoanthropus dawsoni
- Big Brain, big jaw, and canines

What was wrong with the piltdown man?

Even though it had convinced many experts that "ape-men" had lived in England long ago, this "man" had a problem it was made up of a chimera of modern human and modern orangutan bits/parts.

going back to Taung child

Robert Broomi a Scottish MD and Paleontologist, asked for permission from Dart to return to Taung, but he found NOTHING.

What was found in the new site near Taung called Sterkfontein (cave)

An adult Au. africanus cranium (Mrs.Pless) - 1947 2.5 MYA

What did Mrs.Plees (adult Au. africanus) share with a chimpanzee?

-small brain (485 ccs)
-prognathic (projecting lower jaw)

What was the conclusion?

From the neck up Au. Africanus looks like an ape
-symplesiomorphy

A non prognathic cranium w/jaws and lower face that doesn't project very far forward in front of the upper face is said to be?

Orthognathic

Sterkfontein Au. Africanus Post Cranium

-had convincing evidence for bipedalism
-the pelvis and lumbar spine show clear functionally significant synapomorphies with homo

What did Au. Africanus share with modern humans?

like modern humans it has a lumbar lordosis
a laterally directed ilium
and a short ilium

LUMBAR LORDOSIS AND THE CENTER OF GRAVITY

Au. Africanus Innominate

-short illium
-was laterally oriented

what are the problems with bipedalism?

- Only one leg on the ground
-the tendency to fall forward to the side with the leg up

What keeps us from falling over?

the lesser gluteal muscles
-gluteus medius (larger)
-gluteus minimus (smaller)
- These counter act pelvic tilt in Au.Africanus and modern humans

What type of ilia do quadruped-like pan have?

dorso-ventrally oriented ilia

What do the lesser gluteal muscles and hamstrings do?

Extend the leg at the hip joint and generate forward motion during walking

What occurs when reoriented?

ilia gluteal muscles become abductors
- stabilize the hip joint during bipedalism
-ONLY hamstrings extend leg @ hip to generate forward motion when walking

WHAT IS THE GENERAL IDEA?

CHANGE anatomy of a site where a muscle attaches to a bone (origin/insertion), CHANGE action of muscle

What function are the lesser gluteal muscles?

a primitive function to extend leg @ hip during quadrupedalism

Was Raymond Dart right?

YES HE WAS
the lesser gluteal muscles were modified in Au. africanus and in modern humans to maintain balance during bipedalism
-derived

Standard Anatomical position

eyes forward, feet and hands forward
later view at left
front-anterior- right

superior

towards the head
e.g the shoulder joint is superior to the hip joint

inferior

towards the feet

medial

toward the midline axis of bilateral symmetry
the nose is medial to the ear

lateral

moving away from the midline axis of symmetry
the thumb is lateral to the pinkie

anterior (ventral)

towards the front
side of the belly

posterior (dorsal)

towards the back
-dorsal fin

skull

superior most part of a human in standard anatomical position

everything else that is not the skull

the post cranium or post cranial skeleton

axial skeleton

ribcage, breastbone, etc

appendicular skeleton

limbs

towards the axial skeleton

proximal
the knee is proximal to the ankle joint

away from the axial skeleton

distal
towards tips of fingers or toes
the wrist is distal to the elbow

skull

superior most part of the skeleton
includes everything

skull has two parts

lower jaw: mandible
not the mandible: cranium

mandible

holds all of the lower teeth, attachment sites for big muscles move the mandible
condylar process- the joint surface where the mandible meets the cranium mobile joint where the mandible meets the cranium temperomandibular joint

orbit

eye sockets

nose hole

piriform aperture

major bones of the skull

mandible lower jaw
upper jaw in halves- maxilla
cheek bones- zygomatic bone
bridge of nose- 2 bones- nasal bones
upper part of orbits and foreheads- frontal bone

two main parts lateral view

braincase-neurocranium
facial skeleton- splanchnocranium

neurocranium and braincase main bones

frontal
temporal
occipital bone
parietal

cranium inferior view

maxilla
temporal
occipital

basicranium

floor of braincase
numerous foramina (holes)
that transmit nerves and vessels

Foramen magnum and side of it mobile joints called occipital condyles where the vertebral column meets the base of our cranium

forelimb bones

clavicle and scapula

humerus

upper arm proximal end participates in shoulder joint
distal end forms the proximal side of the elbow joint

radius

two bones in the forearm
lateral thumb side is the radius

ulna

on the pinkie side
medial side

hand

distal to radius and ulna

hand carpals

irregularly shaped bones that form the wrist

metacarpals

form palm of hand (5)

phalanges

bones in digits
singular: phalanx

hind limb

femur

thigh bone
femoral head- articulates with pelvis to form hip joint

tibia

lower leg
the leg
biggest of the lower leg bones- medial side
most important bone of lower leg

fibula

lateral to tibia

foot

foot tarsals

chunky elements off foot (proximal end) contribute to the ankle joint

metatarsals

long skinny bones

foot phalanges
singular phalanx

toes

ribs and sternum

vertebral column

backbone
made up of vertebrae
spine

pelvis

connects vertebral column to hind limbs

human vertebral column

cervical (7)

human vertebral column

thoracic 12 connect with ribs

human vertebral column

lumbar - lower back- five

human vertebral column

sacrum

human vertebral column

Coccyx (tail)1 fused-up element (4) plays important role in holding muscles that hold pelvic viscera in place

kyphosis

dorsal curvature

lordosis

ventral curvature
feature of humans and bipedal close relatives

pelvis multiple bones (3)

pelvis

sacrum
-a central element of the pelvis
weight transmitted laterally to hip joint then hind limb bones

right and left innominate -pelvis

os coxa

sacrum rigids

separate vertebrate fused together to form one bony sacrum

innominate

deep concavity where the femur meets innominate to form the hip joint
(acetabulum)

innominate

has three parts that are fused
happens later on in childhood development
ilium site of origin or attachment lesser gluteal muscles, ischium, pubis

What specimens from Sterkfontein had convincing evidence for bipedalism?

Australopithecus africanus
-the pelvis and lumbar spine show clear functional sig synapomorphies with homo

What type of cranium did Australopithecus africanus have?

a primate ape-like cranium

What major shift did Australopithecus africanus have?

bipedal like modern humans the first significant major shift in becoming human

Where were many specimens of Australopithecus africanus found?

Cave sites in S. Africa 2.3-3.2 MYA

What did newer specimens of Australopithecus africanus prove?

support previous findings:
-primate cranium
-biped

What EVC and legs did Australopithecus Africanus have?

EVC-458 CC- APE SIZE
SHORT LEGS

WHAT DID RON CLARK FIND?

STW 573 "LITTLE FOOT" STERKFONTEIN
NEARLY COMPLETE Australopithecus africanus skeleton
3.6 MYA
-"Au. Prometheus"?

What is Australopithecus africanus

an Australopithecine

australopithecine?

early fossil hominins; all from africa

What do Australopithecine share with homo?

bipedal
thick enamel
canine reduction

What does Australopithecine not share with homo?

tiny brain (ape sized)
most have larger cheek and teeth

what did the textbook from 1992 say?

Four species of Australopithecine
human fossil record go back 3.2 MYA
Pliocene: 5.3-2.6 MYA
WRONG