Biological Anthropology group assignment:

Hominin characteristics:

• Reduced canine size and less canine dysmorphism

  • due to loss of the canine honing mechanism

• increased molar enamel thickness

  • the thicker the enamel, means a harder and more abrasive diet

• worn down molars means lots of grounding while chewing

  • this indicates coarse vegetation such as roots, nuts, seeds, etc.

• the more modern the hominin, the larger the brain size.

How do we determine brain size?

• Endocasts

  • Impressions of the inner surface of the cranium

  • A larger more rounded cranium indicates a bigger brain

The earliest hominins:

• had small brains and bodies

• ate diverse foods

The australopithecines:

• sexual dismorphism

• smaller canines

• Encephalization: brain starts to get bigger

• maker of stone tools

Gracile variants: Australopiths

Australopiths in general-

• no chins

• Small cranial capacities(-400-550 cc)

• large teeth, particularly back teeth (molars) (esp. Paranthropus species)

Australopithecus afarensis: “Lucy”

• A. afarensis: tooth rows parallel

  • Canines relatively large and pointed

• a lot of sexual dimorphism

Australopithecus africanus:

• small cranial capacity (small brain)

• face doesn’t stick out as much (pragmatism)

• Cheeks come out in a v-shape zygomatic flare

Australopithecus sediba:

• relatively flat face

• cheekbones (zygomatic arches) less flared

Robust variants: Robust Australopithecus

Megadont adaptation:

• massive canine teeth

• Large sagittal and nuchal (neck) crests

• expansive cheek bones

  • for attachment of powerful chewing muscles

• diet of tough, fibrous foods (grounding teeth?)

Summary of macroscopic traits that are associated with early hominins

• Location of the Foramen Magnum

• The face angle becomes more verticle

• Zygomatic flare

• Prognathism is pronounced

• Brain sizes are still small, but early signs of encephalization

• Teeth still relatively large

• Sagittal crest in megadonts

Tool usage:

• Around 1.2 million years ago we started to see increases in tool complexity

  • lower paleolithic

hand axes - multifunctional:

• cutting/building, hunting, protection

Cleavers, scrappers:

• Striking off large pieces of stone and deliberately shaping them afterward

Oldwan stone tools:

• Choppers:

  • Rounded stones with a sharp edge, used for cutting, chopping, and scraping

• Flakes:

  • Sharp-edged fragments chipped off from a larger stone, used for slicing and butchering

→ made from fractured stone like quartz

Neanderthal teeth:

• show wear that patterns that suggest they were used as tools

Neanderthanl variant: NON HUMAN

• Cold variant: larger and stockier

  • thick skulls

  • teeth with a lot of wear from using them as tools

  • jaw and teeth would have been under a lot of stress

  • forward-projecting face away from brain

  • Large nasal cavities and sinuses

  • long faces

  • heavily worn incisors (front teeth)

Homo erectus:

• the same as Homo neanderthalensis, except for:

  • smaller cranial capacity

• The cranial vault was long, low

• Sloping forehead(low) + heavy brow ridges (supraorbital torus)

• Projecting face

• Heavy jaw, but small molars; Shovel-shaped incisors

• Sagittal keel(not crest)

Archaic Hominins:

• Primitive traits - brow ridges still large, cranial bones still thick, receding forehead

• Derived traits - smaller teeth, even larger cranial capacity(1300cc) , parallel-sided skull vault, maximum breath at the crown

• The head is wider at the crown

African archaic hominins:

• Partial cranium

  • Low vault, heavy brow ridge, thich cranial bones, 1,250cc, cut marks

  • Cannibalism?

• Cranium, low vault, sloping forehead, heavy brow ridge, modern cranial capacity

Homo heidelbergensis:

• Derived traits: skull is rounded, higher, has thinner skull bones than H. erectus

• Primitive traits: Brow ridges are still heavy, has a prominent occipital torus(like H.erectus), lack of chin

• Big game hunting?

• Evidence of fire-altered tools (Israel site)