ANTH 260 Fossil Hominid Lab Thursday, April 4, 13 Handling fossil casts • Treat them as if they were authentic specimens • Use care & professional integrity • Casts are very expensive • Casts represent the remains of actual individuals • Leave casts at same table, keep over table Thursday, April 4, 13 Anatomically speaking • Need a fixed position from which to make relative references • “Anatomical position” Thursday, April 4, 13 Anatomical planes • FRONTAL (or coronal) separates the body into Anterior and Posterior parts • MEDIAN (or midsagittal) separates body into Right and Left parts • HORIZONTAL separates the body into Superior and Inferior parts • SAGITTAL any plane parallel to the median plane Terms of position: •Superior (closer to the head) vs. Inferior (closer to the feet) •Posterior/Dorsal (back side) vs. Anterior/Ventral (front side) •Medial (closer to center) vs. Lateral (farther from the center) •Proximal (closer to the origin of structure) vs. Distal (further away from the origin) Thursday, April 4, 13 Some bones: Cranial • • • • • • • • • • Cranium: skull minus lower jaw Calvarium: skull cap, skull minus “face” Occipital: very back of skull - Foramen Magnum Nuchal chrest: bump on occipital bone Frontal: forehead, top of nose, behind eyes Parietal: (2) top, sides Temporal: (2) location of ears, connects to... Zygomatic arch: (2) cheek bones Maxilla: upper jaw - Mental protuberance: chin Ramus: (2) side of jaw Sutral: form in between bones of skull, in sutra lines Sagittal keel (vs. sagittal crest) Thursday, April 4, 13 Ramus Some bones: Post-cranial • Humerus: upper arm, largest arm bone • Radius: lateral forearm bone (thumb side) • Ulna: medial forearm bone (pinky side) • • • • • • Contains trochlear notch & olecranon process Femur: upper leg bone Tibia: shin bone Fibula:smaller lower leg bone Patella: knee bone Feet: Tarsals→Metatarsals→Phala nges - Big toe = Halux, only 2 Hands:Carpals→Metacarpals →Falanges - Thumb, only 2 Thursday, April 4, 13 Some bones: the Pelvis • Ilium: side hipbone that flares up • Ischium: “sit bones”, has hole for leg • Pubis: front part of pelvis • 1/2 of a pelvis (all 3 of above) = Innominate • Innominate - Thursday, April 4, 13 Obturator foramen & sciatic notch ~ sex determination Obturator foramen: ♀= small, triangular, ♂= large, oval Sciatic notch: ♀= wide, >90°, ♂= narrow, <90° • Dentition Homodonts (all teeth the same) vs. Heterodonts (differentiation of teeth) • • All mammals and primates are heterodonts Dental formula: the layout of one quadrant - Platyrhini (New World monkeys): 2-1-3-3 - Catarihni (Old World monkeys & apes): 2-1-2-3 Molar patterns - Cercopithecoidea (Old World monkeys): X-4 - Hominoidea (apes & humans):Y-5 Thursday, April 4, 13 Ape-Human Comparisons • • Thursday, April 4, 13 Bipedalism: 3 osteological traits - Halux, Foramen magnum, pelvis/femur Pelvis: Apes, long, skinny ilium; human iliums, shorter, wider. • Cranium: Apes, post-orbital constriction; humans, no. Apes, low maximum skull breadth; humans, high. • Face: Apes, prognathic (snouts); humans, orgnathic (mouth) • • Jaw (dental arcade): Apes, rectangular; humans, parabolic Teeth: Apes, canine shearing complex, diastema; humans, canine reduction. Australopiths • At least 7 species • Only found in Africa • Two types: - Gracile: Australopithecus afarensis, A. africanus Thursday, April 4, 13 Robust: A. robustus, A. boisei, A. aethiopicus - e.g. Paranthropus Homo Thursday, April 4, 13 • • • Early fossils: 2.4-1.4 MYA • • • • • Tool use Craniums: larger, higher, rounded Diet & chewing: <prognathic, >orgnathic, smaller mandible, tighter teeth Use/control of fire (?) First to leave Africa (?) By 800KYA, “archaic” Homo sapiens Neanderthals: 130KYA-30KYA Lab assignment • Read (skim) texts • Complete Lab Exercises 13.2, 13.3, 14.1, 14.2 • Make comparisons relatively • Keep big picture in mind, point is to understand differences in fossils based on direct observation • Move about tables to work with all fossils Thursday, April 4, 13