Lecture 17 Outline of Last Lecture I. Fossil dating Outline of Current Lecture II. Early homininsCurrent LectureShared traits of modern Humans:LCA - Pre-AustralopithicusFrom ape to hominin Anthro 1031st editionAustralopithicusearly primitive specieslater 'derived' species - diversificaitonEarly HomoEarliest Hominins:(pre-Australopithicus)Sahelanthropus tchadensis: around 7.0-6.0 myaOrrarin tugensensis: around 6.0 myaArdipithecus ramidus: 5.8-4.3 myaSahelanthropus tchadensis:Similar to chimpanzee brainsmall brainThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.possibly bipedalforest, lakeOrrorin tugenensis:femur suggests bipedalcanine worn at tipforest habitatArdipithecus:short caninesslightly thicker enamelbig toe abducted, but stiff footarboreal quadraped; bipedalforestLCA/Early Hominin summary3 kinds: Sahelanthropus tchadensis, Orrarin tugenensis, Ardipithicus ramidusarboreal and terrestrial - might have used trees to sleep in or gather fruit and walked on ground during the day'mosaic' - various combinationsmoderate dimorphism -> reduction in male-male competitionwooded environment'bipedal apes'Second 'set' of early hominids1. Pre-Australopithecus2. Australopithecus3. Early HomoAustralopithicus anamensis - 4 mya, Kenya, Ethiopiabig canines (ape)parallel tooth rows (ape)but, thick enamel (hominin)1973 - Found 'Hadar'Australopithecus afarensisEthiopiafemur angles inward and ends of bones are like buttresses, so you can tell it is a hominin bone (bipedal)Australopithicus afarensis: 3.9-3.0 myamany individualslarge molars, thick enamelobvious biped, but...arboreal too?Laetoli footprints - bipedal: heel strike, in-line toe'Lucy''first family'Child - Dikika child, CAT scan shows baby teeth with permanent teeth forming in maxilla and mandible. Development of teeth is reminiscent of chimps, not homo sapiens. Develop quicker - life history is quicker - adult teeth grow in quickersome sexual dimorphism - less than chimp, more than
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