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CHAPTER 11: EARLY HOMININSThere are 3 categories of Early Hominins: (1) Earliest Hominins; (2) Australopithecines; (3) Robust Australopithecines.Bolded information = important characteristic or trait1. EARLIEST HOMININS1.) S. tchadensis – Toumai (found in Chad  Africa)320-350 cc sized brain (chimplike), primitive teethFlat face, brow ridge, foramen magnum underneath (biped)2.) Orrorin tugenensis (6 mya)Molars smaller than A. ramidus -- thick enamel like usArms/fingers adapted for climbingThigh bone more human like (bipedal)Mixed woodland/savannah environment3.) Ardipithecus ramidus (4.5-4.3 mya)Noted for enamel thickness4.) Ardipithecus kadabba (4.4 mya)Found in Ethiopia  45% of skeleton found  data gathered for 15 yearsClassified as different species because canines are more chimp-likeArdipithecus is hominin because of canines and bipedalismBipedal pelvis** but opposable big toe**Not a knuckle walker; small brain***A. ramidus and A. kadabba considered same species now  classified as Ardipithecus ramidus (“Ardi”)2. AUSTRALOPITHECINES1.) Australopithecus anamensis (4.2-3.8 mya)Found in Kenya (mixed woodland environment)More derived characteristics = large molars, thick enamel, small canines, knees and ankles indicate bipedalismMore primitive = climbing arms, more ape-like skull, receding chinDental arcade = more U-shaped (ape) than V-shaped (us)2.) Australopithecus afrarensis (Lucy) (4-3 mya)13 individuals found in multiple areas across AfricaWoodland/drier savannah (Only in East Africa)Primitive (ancestral) traits = 404cc brain size (same as chimp); base is flared; sub-nasal prognathism; non-projecting caninesDerived traits = teeth and jaws intermediated between apes and humans (between U-shaped and parabolic)Medium-sized caninesModest diastema (gap between molars)< canine dimorphism than chimp but > than usSmaller inner cusp than chimps (1) and us (2)Primitive bipedalism, less efficient  ilium oriented back so abductors are less efficient  shorter legs = slower  wider pelvisSexual dimorphism = ratio 1.5 (male) : 1 (female)Greater sexual dimorphism than humans, chimps and bonobosMixture of arboreal and terrestrial traitsMore efficient bipedalism, less efficient climbingSleeping in trees; long arms; curved fingers; bipedal pelvis3.) Australopithecus Africanus (Taung – 3 years old) (3-2.2 mya)1st Australopithecine discovered – only South Africa442 cc = brain size (similar to A. afarensis)More modern teeth than A. afarensisSmall brain, modern dentition = dentition evolved before brain sizeLocation of foramen magnum indicates bipedalismDerived traits = shorter face; subnasal prognathism; < dimorphic caninesDerived traits NOT shared with us = large molars for chewing (post-canine megadontia)Rapid maturation (like chimps)4.) Kenyanthropus platyops (3.5-3.2 mya)Mixed woodland savannah environment – Lake Turkana; AfricaThick enamel but smaller molars than all but A. ramidusBroad, flat facePossibly distorted afarensis5.) Australopithecus garhi (2.5 mya)Found in Ethiopia450 cc = brain sizeVery prognathic face; sagittal crestLegs longer than arms, unlike chimps & A. afarensisCanines, premolars, and molars larger than afarensis & africanusDiffered from other australopiths but lack derived features of other hominins3. ROBUST AUSTRALOPITHECINES1.) Australopithecus aethiopicus (2.5 mya) (“Black Skull”)Lake Turkana, KenyaJaw joint similar to A. afarensis, chimps, gorillas whereas we have a modified jaw hingeSame brain, body size as A. afarensisSimilar postcranially to Australopithecines with small brains relative to body sizeHuge molars, large lower jaw for powerful chewingFlared zygomatic arch makes face look flatHuge temporalis and masseter muscles for chewing2.) Australopithecus boisei (2.2-1.3 mya)Found TanzaniaRobust size = larger body, molars for really heavy chewing3.) Australopithecus robustus (1.8-1 mya)South Africa530 cc = brain size (bigger brain than other australopithecines)Sexual dimorphismBipedal; more heavy chewing than africanus (seeds, nuts, meat?)4.) Australopithecus sediba (1.9-1.78 mya)Found 2010 by Lee Berger, South AfricaClosest morphological comparisons are to A. africanus & H. erectusCombo of ancestral & derived traitsCranium, body size, proportion = austrolopith420 cc = brain sizeReduced size of molars & pelvis = homo trait (seen in h. erectus)ANT2511: INTRODUCTION TO PHYSICAL ANTHROPOLOGY CHAPTER 11: EARLY HOMININSThere are 3 categories of Early Hominins: (1) Earliest Hominins; (2) Australopithecines; (3) Robust Australopithecines.Bolded information = important characteristic or trait1. EARLIEST HOMININS1.) S. tchadensis – Toumai (found in Chad  Africa) - 320-350 cc sized brain (chimplike), primitive teeth - Flat face, brow ridge, foramen magnum underneath (biped)2.) Orrorin tugenensis (6 mya) - Molars smaller than A. ramidus -- thick enamel like us - Arms/fingers adapted for climbing - Thigh bone more human like (bipedal)- Mixed woodland/savannah environment 3.) Ardipithecus ramidus (4.5-4.3 mya) - Noted for enamel thickness4.) Ardipithecus kadabba (4.4 mya) - Found in Ethiopia  45% of skeleton found  data gathered for 15 years - Classified as different species because canines are more chimp-like- Ardipithecus is hominin because of canines and bipedalismANT2511: INTRODUCTION TO PHYSICAL ANTHROPOLOGY - Bipedal pelvis** but opposable big toe** - Not a knuckle walker; small brain ***A. ramidus and A. kadabba considered same species now  classified as Ardipithecus ramidus (“Ardi”) 2. AUSTRALOPITHECINES 1.) Australopithecus anamensis (4.2-3.8 mya) - Found in Kenya (mixed woodland environment) - More derived characteristics = large molars, thick enamel, small canines, knees and ankles indicate bipedalism- More primitive = climbing arms, more ape-like skull, receding chin- Dental arcade = more U-shaped (ape) than V-shaped (us)2.) Australopithecus afrarensis (Lucy) (4-3 mya) - 13 individuals found in multiple areas across Africa- Woodland/drier savannah (Only in East Africa) - Primitive (ancestral) traits = 404cc brain size (same as chimp); baseis flared; sub-nasal prognathism; non-projecting canines- Derived traits = teeth and jaws intermediated between apes and humans (between U-shaped and parabolic) - Medium-sized canines- Modest diastema (gap between molars) - < canine dimorphism than chimp but > than us- Smaller inner cusp than chimps (1) and us (2) - Primitive bipedalism, less efficient  ilium oriented back so


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