Lecture 7 Flashcards
Australopithecines
- Australopithecus anamensis 4.2-3.9mya
- Australopithecus afarensis ~4.1-3.9/2.8mya
- Australopithecus bahrelghazali ~3.5-3.0mya
- Australopithecus deyiremeda 3.5-3.3mya
- Australopithecus garhi ~2.5mya
- Australopithecus africanus ~2.9-2.4mya
- Australopithecus sediba ~1.95-1.78mya
Kenyanthropines
- Kenyanthropus platyops ~3.5-3.2mya
Paranthropines
- Paranthropus robustus 1.8-1.4mya
- Paranthropus boisei 2.3-1.4/2mya
- Paranthropus aethiopicus 2.7-2.3mya
Australopithecus sp. Key features
*Sexual dimorphism greater
than among later hominins
*Small body
Size: 29-33/45-59kg, 1.05 1.51m
Pan: 32-47/40-60kg;up to 1.2m
Small cranial capacity (400-550cm3)
But larger than Pan [Pan 275-500, av. 360cm3]
*Relatively large, prognathic faces. But less so than
Pan!
*Large back teeth with very
thick enamel but some species have some or all of: distinct premolars, reduced
canines and pronounced
incisors
*Postcrania suggest bipedalism but also some retained aboreality
Australopithecus anamensis age
- ~4.5-3.9mya
Australopithecus anamensis location
East Africa, Turkana region of Kenya
Australopithecus anamensis body size
- c50kg male
- c33kg female
- Substantial sexual dimorphism
Australopithecus anamensis teeth
- Narrower, more parallel jaws
- Large incisors: frugivorous?
- But thick enamel also points to seeds and nuts
- Microwear on teeth suggests mix of grass and fruits
Australopithecus anamensis bipedalism
- Tibia morphology very well adapted to bipedalism: expanded upper surface, orientation of ankle joint
- But still some retained arboreal features: long forearms and some features of wrist bones
Australopithecus afarensis age
- c4-3mya
Australopithecus afarensis location
East Africa
* Tanzania: Laetoli
* Ethiopia: Hadar, Middle Awash
* Ethiopia: Fejej, Lower Omo Valley
* Kenya: Koobi Fora, Allia Bay, South Turkwell
Australopithecus afarensis specimens
*One of the best-known early hominins:
large sample of different specimens
- Lucy
The ‘first family’ AL 333
* 216 specimens, at least 17 individuals including
9 adults, 3 adolescents and 5 young children
* Mainly jaws and teeth but some humeri and
femora
Dikika baby:
* Almost entire skull and torso and most parts of
limbs
* ~3yrs old?
Australopithecus afarensis size
- Male c45kg, 1.51m tall
- Female 29kg, 1.05m tall
Australopithecus afarensis brain size
- 365-500cm3, av. 410cm3
Australopithecus afarensis face
- Lower face projects forward
- Short and low forehead,
receding chin
Australopithecus afarensis teeth
- Long, narrow, parallel teeth rows
- Chewing teeth larger than
chimpanzee, incisors smaller - Thick enamel on teeth: nuts and
grains important to diet?
Australopithecus afarensis: bipedal?
- Laetoli footprints: gait very similar to modern humans
- Barrel-shaped chest
- Scapula positioned more cranially like chimpanzees
- Foot very like modern humans’
- But arboreal traits!
- Relatively long arms (ratio similar to modern baboons)
- Fingers long and curved
The ‘Burtele Foot’
- 3.4mya, from Woranso-Mille
in the Afar region of Ethiopia - i.e. same rough time period
and region as A. afarensis - BUT – opposable big toe!
- More similar to Ardipithecus
ramidus (~4.4mya)? - i.e. multiple lineages around
at the same time - And multiple different types of
bipedalism (still!)
Australopithecus deyiremeda location
- Burtele, Woranso-Mille, Ethiopia
Australopithecus deyiremeda age
- 3.5-3.3mya
Australopithecus bahrelghazali age
- c3.6-3mya
Australopithecus bahrelghazali location
- Central Africa: the Bahr el ghazal
region, Chad
Australopithecus bahrelghazali other facts
- Not much known about the
species: discoverers have not
shared it with the community - Similar to A. afarensis: regional variant of same species?
- Premolars with three roots
(unlike afarensis) - Enamel thickness similar to A. afarensis: similar diet of nuts and
grains?
Kenyanthropus platyops age
~3.5-3.2mya
Kenyanthropus platyops location
East Africa: Kenya
Kenyanthropus platyops specimens
- Very little material: skull, upper jaw and
teeth known – skull is v. distorted - Skull size within australopithecine
range - Mid-face flatter
- One molar: unusually small, with thick
enamel - Australopithecine?
- A. afarensis?! Just distorted?
- Definitely not a paranthropine!
Australopithecus africanus age
- c3-2.4mya
Australopithecus africanus location
- South Africa: Taung;
Sterkfontein; Makapansgat;
Gladysvale
Australopithecus africanus size
- Male 41kg, 1.38m tall
- Female 30kg, 1.15m tall
Australopithecus africanus cranial capacity
- 387-570cm3, av. 478cm3
Australopithecus africanus bipedal
- But forelimbs relatively longer than expected
- Curved phalanges
Australopithecus garhi age
C2.5mya
Australopithecus garhi location
- East Africa: Bouri, Middle Awash, Ethiopia
Australopithecus garhi cranial capacity
c450cm3
Australopithecus garhi paleoenvironmental evidence
- Open lake margin habitat and open plain
Australopithecus sediba age
- C1.95-1.78mya
Australopithecus sediba location
- South Africa: Malapa
Australopithecus sediba specimens
- Minimum of 2 individuals
represented by 135 fossil
elements
Australopithecus sediba bipedal
- Habitually
- But long upper limbs
Australopithecus sediba height
1.27m
Australopithecus sediba brain size
~420cm3
Australopithecus sediba foot
- Ankle very human-like
- But lighter calcaneum and more robust
medial malleolus - Unique form of bipedality?
- Did multiple species evolve bipedal traits independently?!
- Convergent evolution i.e. homoplasy
Australopithecus sediba pelvis
- Partials found, reconstructed
Similar to australopithecines:
*Large biacetabular diameter
*Small sacral and coxal joints
*Long pubic rami
but also some derived Homo-like features:
* More vertically oriented and sigmoid shaped iliac blades
* More robust iliac body
* Shortened ischia
* More superiorly oriented pubic rami
Paranthropus sp. key features
Adaptations for
powerful chewing:
* Sagittal crest for
muscle attachment
* Wide cheekbones
* Front teeth
relatively small,
back teeth very
large
* Jaws very thick
and deep
* Unique dental
development and
eruption sequence
Slightly larger brain:
* ~500-525cc
- Bipedal
Small body size:
* 32-49kg
* 1.1-1.37m
Paranthropus aethiopicus age
- C2.5-2.3mya
Paranthropus aethiopicus location
East Africa:
* Kenya: Lake Turkana
Paranthropus aethiopicus specimens
- The ‘black skull’ KNM-WT-17000
- No postcrania!
- Bipedality assumed as per other australopithecines/
paranthropines
Paranthropus aethiopicus cranial capacity
~410cm3
Paranthropus aethiopicus face
- Wide and projecting, ‘dish-shaped’
Paranthropus aethiopicus skull
- Narrow and small
Paranthropus aethiopicus paleoenvironmental
- From bushland to open woodland
Paranthropus boisei age
- c2.3 – 1.4mya
Paranthropus boisei facts
- One of the first finds to be dated using
the then-new geochemical dating
methods!
Paranthropus boisei location
East Africa:
* Tanzania: Peninj
* Ethiopia: Shungura formation, Omo
region; Konso Gardula
* Kenya: Koobi Fora, Baringo region, West
Turkana
* Malawi: Malema
Paranthropus boisei size
- Male c49kg, 1.37m tall
- Female c34kg, 1.24m tall
- Pronounced sexual dimorphism but small canines
Paranthropus boisei cranial capacity
444-588cm3
Paranthropus boisei skull
- Sagittal crest and strong muscle attachment areas
- Narrow braincase, esp. postorbital
- Very robust mandible
Paranthropus boisei face
- Projects less than some earlier hominins
Paranthropus boisei teeth
- Large crowns and thick enamel
- Molars some of the largest of any hominin, worn flat
- Diet of seeds, nuts and/or hard covered fruits
- but … microwear studies suggest fruit?
Paranthropus boisei bipedal
Bipedal but retains some arboreal adaptations
Paranthropus boisei paleoenvironment
- Occupied more open environments e.g. savannah,
open/scrub woodland
Paranthropus robustus age
- c2-1.5mya
Paranthropus robustus location
South Africa
Paranthropus robustus size
- Males: 40kg, 1.32m tall
- Female 32kg, 1.1m tall
Paranthropus robustus brain size
- 475-625cm3
Paranthropus robustus hand
- Derived: precision thumb and refined manipulation control:
tool use?! - Found with bone tools showing signs of being used for
digging?
Paranthropus robustus bipedal
- Hip and pelvic anatomy show bipedalism
- Arboreal adaptations reduced: shorter forelimbs?
Paranthropus robustus paleoenvironmental
- More open savannah or bush/wooded grassland?
Folivores/herbivores
- Incisors used for shearing
- Emphasis on molars for grinding
- Tooth relief: developed molar crests for grinding
- Simple gut and stomach with expanded compartment
for bacterial fermentation of cellulose in leaves; large
volume - Enamel thickness varies with
abrasiveness/toughness of foodstuffs
Frugivore teeth/guts
Frugivore- an animal that feeds on fruit
- Intermediate: depends on toughness of fruits!
*Broad incisors
*Low rounded molars
*Long small intestine
Carnivores
- Larger incisors and canines
- Molars less pronounced
- Teeth often rounded and low
- Gut dominated by small intestine, main area for
absorption
Diets: teeth microwear
- Microscopic damage and abrasions on teeth: more abrasion = tougher foods
- Folivores have long narrow scratches on incisors
- Frugivores, especially tough fruit eaters, have more pits on tooth surfaces
Species teeth
A. anamensis
* Large incisors, but thick enamel
* Microwear on teeth suggests mix of grass and fruits
A. afarensis
* Chewing teeth larger than chimpanzee, incisors smaller, thick enamel
* Microwear: mix of narrow scratches and pitting
A. bahrelghazali
* Enamel thickness similar to A. afarensis
A. africanus
* Larger chewing teeth than
A. afarensis
* Less pitting than Paranthropus robustus, more, longer scratches on teeth
A. sediba
* Microwear suggests tough foods
* Plant fossils in tooth plaque showed varied diet: leaves, fruits, bark, sedges, grasses but
no savannah grasses
Kenyanthropus platyops
* One molar: unusually small, with thick enamel
P. robustus
* thick tooth enamel
* More pitting and less scratching than A. africanus
P. boisei
* Molars some of the largest of any hominin, worn flat
* but … microwear studies suggest fruit?
Species palaeoenvironmental evidence
A. anamensis
* Variety of habitats including riverine
woodlands and gallery forests
A. afarensis
* Laetoli was open savannah
* Hadar was forest margin/open
woodland
* Ecologically diverse species adapted
to different ecological niches/zones?
A. garhi
* Open lake margin habitat and open
plain
P. aethiopicus
* From bushland to open woodland
P. boisei
* Occupied more open environments
e.g. savannah, open/scrub
woodland
* Lake margins
P. robustus
* More open savannah or
bush/wooded grassland
C3 plants
- ~95% of plants are C3 plants e.g. trees,
shrubs - Lower in 13C (carbon istope 13; remember
isotopes are forms of an element with different
numbers of neutrons) - Low 13C in fossils = fewer grasses, sedges
etc. in diet, more closed environments? - Or animals whose diet is high in these
foodstuffs!
C4 plants
- More water efficient
- C4 plants live in hot habitats e.g. tropical
grasses, sedges - Higher in 13C
- High 13C in fossils = more grasses, sedges
etc. in diet, life in more open environments? - Or animals whose diet is high in these
foodstuffs!
Diet teeth- incisor size
- hominins have quite small incisors for body size
- Australopithecines’ are actually larger than humans’ or paranthropines!
Diet teeth- molar size
- Australopithecines’ molars are smaller than paranthropines’, early Homo are intermediate
Diet teeth- teeth relief
- Australopithecines have relatively flat, blunt teeth
- Inefficient at tough foods even pliant ones like meat: soft fruits?
Diet teeth- enamel thickness
- Australopithecines and paranthropines both had thick enamel
Diet teeth- microwear
- Australopithecines a mix of grass and fruits
- Paranthropines more harder foods?
Diet teeth- mandibular biomechanics
- All archaic hominins show robust mandibles
- Paranthropines’ more robust than australopithecines’!
Diet teeth- paleoenvironments
- Mixed, mosaic environments for australopithecines!
- Possibly more open environments for paranthropines
Diet teeth- isotopic evidence
- Lots of variability among australopithecines and P. robustus: only P. boisei really shows evidence of significant amounts of
grassland resources
