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Description
Flashcards by Stephanie Vasque, updated more than 1 year ago
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Created by Stephanie Vasque
almost 11 years ago
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| Question | Answer |
| The first Homonoid fossil found was in the country Chad in Africa. What Genus was this fossil? and common name? | The genus for this fossil is Sahelanthropus, and the common name is "Toumai' |
| How was the Toumai fossil dated, and what is the relative date of the fossil? | Dated by biostatigraphy (comparing this fossil to the layers above/below) and is estimated to be between 6 and 7 MYA in the Late Miocene |
| This fossil is a nearly Complete cranium and right mandible set and named 'hope of life' | The Toumai fossil, genus Sahelanthropus |
| What are some of the primitive features of the Sahelanthropus, 'Toumai' fossil? | Toumai is a cranium fossil. It is distorted (flattened). Primitive: It shows a small ape size brain (320-380cc). Truncated Occipital. Large Supraorbital torus (eyebrow ridge). Thick Intraorbital pillar. |
| What are some of the derived features of the Sahelanthropus, 'Toumai' fossil? | Toumai derived features include: Having less progantism than chimps. Long/flat/horizontal nuchal plane. Anterior foramen magnum. Shorter basicranium. Possibly bipedal. Small canine worn on Apex. No diastema or honing complex. Intermidiate post-canine (premolar) enamel thickness. Central Africa cradle of mankind? |
| What are some problems/inaccuracies with the Toumai Fossil? (6) | 1. The fossil is distorted 2. The digital reconstruction may be inaccurate/ not a proven hominini. 3. The fossil has no lower limb, only upper cranium. 4. There is only ONE fossil, hard to compare with others. 5. Is this Ape or Hominini 6. Ancestor of the Apes with similarities to Homo |
| What is the name of the fossil found in rift valley at Lake Baringo in W Kenya? Dating method? estimated age? | Fossil genus is Orrorin, 'The Millennium Man'. It was dated by biostratigraphy and potassium/argon dating approximately 6MYA (slightly younger than Sahelanthropus) |
| What year was the millenium man found in...? and the Toumai? | 2000 (MM) and 2001(toumai) |
| What portions of the fossil Orrorion are preserved? | Teeth, jaw, and femur. |
| What are the dental features of the Genus Orrorin? (Millenium Man) | Dentition: ape-like incisors and 4th premolar. Upper canines like female chimps. Smaller molars. Enamel thickness is the only derived trait. |
| What are the post-cranial features of the genus Orrorin? Millenium Man | Post-cranial: humerus and fingers similar to chimps/afarensis. Anatomy for climbing trees still. (proximal) femur adapted for bipedalism. groove on humerus(arm), long humerus, closest to Australopithecines. Cortical bone thickest on the inferior end of the femur(leg) because unbalance in the gluteal muscle. |
| Main point on the Genus Orrorin? | Primitive cranium. Deived features on the teeth. teeth retain most ape-like features. significant evidence of bipedalism similar to Australopithecines. |
| WHat fossil (genus) was found in the Afar triangle, in Middle Awash Ethiopia? | Genus Ardipithecus. Species: Ramidus and kaddaba. |
| Genus Ardipithecus, species: kaddaba. Main features/age/dating method? | Ape like honing complex, confused as A. ramidus. dated by Argon using volcanic rock at 5.5 to 5.8 MYA |
| Genus Ardipethecus, species: ramidus. dating method and condition of fossil? | Used Ar/Ar dating and tuff and the condition of the fossil was in very bad shape (deteriorating) until restored. |
| This fossil named after 'ground root' fits after genus sahelanthropus and Orrorin. | Ardipithecus ramidus/kabbada |
| Cranium features of the Ardipithecus ramidus: | Primitive: 1. Small brain 2. Prognathism Derived: 3. thin intro orbital pillar 4. thin supra orbital torus 5. open angle from skull/orbits for bpedalism |
| Ardipithecus ramidus dental/teeth features: | Primitive: 1. Largest canines of all Hominins 2. thicker dental enamel 3. chimp like morphology Derived: 4. small incisors. 5. no honing complex |
| Ardipithecus ramidus limb features: | Primitive: 1. Muscular arms 2. Locked elbow for climbing trees 3. proconsul like hands/no knuckle walking |
| Ardipithecus ramidus foot features: | 1. Flat feet 2. Not adapted to bipedalism derived: 3. adapted to plantigrady (heels of foot flat on ground) not tree climbing 4. femur adapted to bipedalism 5. pelvis adapted to bipedalism and tree climbing (hmm..) |
| what is the main Problem with Ardipithecus ramidus fossils and characterizing them? | We aren't sure if Ardipithecus ramidus is bipedal or not, it has some features for climbing trees and some features for walking. May be an ancestor for the chimps. |
| What are the first three genus of homonins that are the most primitive compared to modern humans? | Genus Sahelanthropus, Orrorin, and Ardipithecus |
| Why did the first hominins branch off from their ape like ancestors? | 1. climate is cooling 2. extension of savanna 3. Ardipithecus living in patchy woodland needed to walk to each bush that's farther apart now |
| Basic reason for bipedalism is: | Hominin bipedalism formed as a response to forest fragmentation, going from large food resources to small food patches. |
| Compared to previous hominins how has the australopithecus diet changed/adapted? other features? | Australopiths have adapted to eating harder and more brittle foods. They are the definite first biped (anamensis) |
| What is the name for the first Australopithecus genus, alive roughly 3.9 to 4.2 MYA? found by? and location found? | Australopithecus Anamensis, found by Leakey and Kimeu in the rift valley in N kenya, south of Ardipithecus ramidus. |
| What is one fact that we know is true about Australopithecus Anamensis that we didn't for sure know about Ardipithecus ramidus? | Australopithecus is for sure bipedal, because the knee is angled in towards the midline making the ankle is nearest the body's center of gravity . in ramidus it was unsure (no proven 100% evidence) |
| Dental features of Australopithecus anamensis: | primitive: 1. Large canines 2. prognathism 3. U shaped dental aracade Derived: 4. Thicker molar enamel 5. wider molars |
| Where type of climate did Australopithecus Anamensis most likely live in? | In the woodland area, grassland, mosaic(patchy) habitats. Big shift from forest(previous hominins to dry habitats) which led to dietary adaptations (harder food/more brittle) |
| Australopithecus afarensis, coming after anamensis, is what age? | 3-3.7 MYA, (anamensis is 4.2-3.9 MYA) |
| Australopithecus Afarensis found in what two sites? | 1. Hadar (etheopia) more recent 3-3.4 and 2. Laetoli (tanzania) later 3.5-3.7 |
| the sample of Australopithecus afarensis is found between what? | It is found between layers of volcanic ash |
| What famous artifact was found in Laetoli, Tanzania dated from 3.6 mya? | In Laetoli, footprints were found of late hominins formed quickly. |
| What was the enviornment in Laeteli, Tanzania like? | Mosaic (patchy) habitat, woodland, grassland. No savanna |
| T/F: The Hadar, Etheopia samples of Australopithecus afarensis has evidence of a knee joint specialized for bipedalism. | True. found in 1973 by Johnson. |
| the fossil 'Lucy' belongs to what hominin? age? important facts? | Australopithecus afarensis, found in 1974, hips specialized for bipedalism. |
| What is the 333 site? | Found in 1975, the remains of 13 individuals that died of natural disaster are well preserved. they are now known as the 'first family' |
| Australopithecus Bahrelghazali is usually fit/combined with what hominin? | Australopithecus afarensis |
| Australopithecus afarensis dentition: | 1. post canine megadontia (cheeck teeth larger than expected) 2. large incisors(p) 3. diastema(p) 4. canine ware on both apix and sides 5. P3(first premolar) has one cusp(p) 6. U shaped dental arcade, getting wider though. |
| Canines can ware on the tip (apical) or one the sides (mesial and distal). which sides are ascribed to apes and which to humans? | Humans have apical wear and apes have distal/medial wear. |
| Post canine megadontia (larger cheek teeth) is not found in what homonin? | It is not found in Ardipithecus |
| Cranium features of Australopithecus afarensis: | Primitive skull: 1. shallow tmj 2. base of skull is unfflexed 3. flat mastoid 4. strong prognathism 5. ape like sagittal crest (high at the back) 6. small brain |
| Body plan of Australopithecus afarensis 'Lucy': | 1. hip/knee/ankle=bipedalism 2.pelvis lower and broader 3. pelvis wider, smaller birth canal 4. convergent big toe and high arch Primitive: 1. long curved fingers/toes 2. short thighs 3. funnel shaped thorax 4. ape-like inner ear |
| What are the two main hypotheses on why a biped would retain these (arboreal) characteristics? | 1. Baggage hypothesis, arboreal traits left over from arboreal ancestors. 2. Functional Hypothesis, these traits are not left overs but meaningful traits used to become better climbers that used trees for safety and feeding |
| A. afarensis 'Selam' a fossil found in Dikka, Etheopia showed what major discovery? | Selam (3.3mya) is a complete skull, with ape-like hyoid bone, had air sacs and ape like scapula. Head of Ape lower body of human. |
| Australopithecus afarensis behavior: | 1. Sexual dimorphism (strong) 2. Male to female ratio is [1.5] 3. butchery suggested by cut marks on bones 4. No tool usage found, but potentially first stone tool user. (need more evidence) |
| Which hominin comes after Australopithecus afarensis? | Australopithecus garhi |
| Approximately what age is Australopithecus garhi? Location found? | garhi is 2.5 MYA, and found in (middle awash) Bouri, Ethiopia |
| A. garhi cranium features: | 1. prognathic (p) 2. sagittal crest (p) 3. small/med brain size450cc(p) 4. primitive traits link it to homo.. need more fossils. |
| A. garhi post cranial features: | Primitive: 1.brachial index (short upper arm, long forearm) Derived: 1. inter-limb index (long femur~leg to humerus~arm ratio..like us) |
| Did the homonin Australopithecus garhi use stone tools? is there proof of this? | No. There have been animal bones near fossil sites with cut marks by stone tools but it is unclear what caused these marks and no tools have been found yet. |
| What are the three robust australopithecines? ages? Locations? | A. Aethiopicus(2.7-2.3 mya E. Africa), A. boisei(2.3-1.4 mya E. Africa), and A. robustus (2-1 mya S. Africa) |
| Which two species of the robust Australopithecines may be the same species/share a lot of similarities? | Australopithecus aetiopicus and Australopithecus boisei |
| What makes up the Megadontia Complex? (there are features) | 1. sagittal crest (top of head) 2. huge temporal fossa (cheek bones) 3. reduced prognathism (head pushed back) 4. heavy alveolar bone (big jaw bone) 5. robust mandible (large jaw/chin) 6. big molars 7.molarized premolars (no more p3 molars) |
| Australopithecus aethiopicus has what kind of dentition? | aethiopicus are known for having primitive looking megadonts, which means they have very large teeth with primitive features. |
| D or P dental features of Australopithecus aethipoicus: | Derived: 1. smaller anterior (frontal incisors/canines) teeth 2. Molarized P3 molar 3. Megadont molars (very super size) |
| what are the PRIMITIVE Australopithecus aethiopicus cranium features? (5) | Primitive: 1. small brain 2. shallow tmj 3. big muzzle(mustache area) 4. flat skull base 5. sagittal crest like gorillas |
| What are the DERIVED Australopithecus aethiopicus cranium features? | Derived: 1. megadont(huge) teeth 2. Huge sagittal crest for chewing |
| What is the single species hypothesis? | basically the discovery of A. boisei and A. habilis living together at the same time disproved the hypothesis that only one single species pf hominin could be present on earth at a time. |
| What specific action was Australopithecus boisei specifically adapted for? | A. boisei was the ultimate chewing machine, the entire skull is adapted to stronger chewing forces. (derived) |
| Which robust Australopithecus has the LARGEST cheek teeth? | Australopithecus boisei has the largest cheek teeth (ultimate chewing machine remember!) |
| What is the main feature (complex?) of Australopithecus boisei? | boisei have a megadontia complex (remember all of the features of this complex!) |
| what are the main differences between Au. boisei and Au. aethiopicus? | Boisei have increased cranial base flexion, deeper mandibular fossa, slightly larger brain, less prognathism... ALL synampomorphies with Homo! |
| How long ago did Australopithecus africanus live? where? | 3-2.4 mya, from South Africa |
| the Taung cave site in South Africa is famous for what fossil? | 'Taung child' fossil of Au. boisei was found in the Taung cave sites and showed that upright posture developed before larger brains. |
| Who discovered the 'Taung child and how? | Raymond Dart discovered the fossil because it was sent to him along with many others in a box. He noticed that it had the brain of an ape yet many human-like characteristics as well. This fossil supported the idea that Africa was the origin for humans! |
| what was piltdown man? | A fake skeleton put together with parts of an ape skull and teeth filed to look human like and attempted to be passed off as a real artifact. very misleading |
| Through Robert Brooms effort, what genus was finally accepted as a human ancestor? | Robert Broom helped Au. africanus become accepted as a human ancestor |
| the fossil STS 14 proved what? | STS 14 proved that Au. africanus was bipedal! |
| why is it difficult to date the cave sites that we find Au. africanus at?? | Its difficult to establish the correct age because there are NO volcanoes nearby and thus no volcanic tuffs left for potassium argon dating. Biostatigraphy is the only form of dating that can be used and sometimes even that can be hard to measure because of shifting land. |
| T/F Au. afarensis is more derived than Au. africanus? | False! africanus is more derived and closer to the human lineage due to similar dental arcades (parabolic), no diastema, and upper canines are less projecting, apical wear on canines, and reduced sexual dimorphism. |
| Major differences between cusp sizes/orientation between africanus and afarensis? | Africanus has strong metaconid (cusp) of the p3 molar and it is not slanted but more straightened out while afarensis is more primitive (oblique and not a strong cusp) |
| Which species is more specialized for Heavy chewing? A. africanus or A. afarensis? | A. africanus! because they had larger cheek teeth and thicker jaw and skull (sagittal crest) adaptations for heavy chewing. |
| what are the cranial synapomorphies between africanus and homo? | 1. temporal and nuchal lines do not meet. 2. skull base is narrower 3. rounded mastoid (near ear) 4. nuchal plane is not steeply inclined. 5. deep madibular fossa 6. temporal muscles are more forward (on top of head) 7. larger brain vs body size ratio 8.robust forelimbs and shorter hindlimbs. 9. less sexual dimorphism. |
| What did Darts killer ape hypothesis state? | found many bones that were thought to be used as weapons/daggers and axes, said our ancestors were brutal and so are we. inspired Taphonomy, studying how to preserve fossils. The site ended up being just bones that were eaten up by leopards that climbed trees and dropped bits of their kill into the caves below and not tools. |
| what genus starts around 2.0 mya? | Australopithecus sediba, in many ways it is very similar to africanus as well as Homo. |
| What does the fossil record of Au. sediba tell you about its relationship with Homo when compared to fossils of similar species? | Pelvis of sediba similar to Homo, perhaps a better walker than africanus. A good ankle for climbing, could be ancestor to Homo |
| A. robustus was around how long ago? | 2-1 MYA |
| T/F A. sediba was the first robust australopith to be discovered. | False. A. robustus was the first robust australopith to be discovered, the very last to go extinct, and ironically the least robust of the three. |
| what synapomorphies does robustus share with Homo? | 1. Larger brain 2. less prognathism 3. increase cranial base flexion 4. deeper jaw joint 5. human like hands Also, has Megadontia features! |
| what is the kenyanthropus platyops? | This is the fossil found in kenya, primitive features, derived flat face and cheek bones pulled forward. 3.5-3.3 mya |
| What is Milankovitch cycles? how many cycles are there? what are they called? | Milankovitch cycles are The different ways the sun exposure can impact climate. (there are three) 1. Precession; planet turning in on itself 2. Obliquity; axis rotation more than 20 degrees 3. Eccentricity; elliptic path around the sun |
| What climatic changes were happening at the end of the pliocene (tertiary period) and begining of the pleistocene (Quaternary period) | 1. The panama Isthmus is formed (panama connects to south america) and this seperates the atlantic from the pacific. 2. contrasted climates begin to develop (hot/cold) and thermohaline circulation changes (flow of hot and cold water) 3. gulfstream increases in salinity in the N. atlantic and deeper underwater in the artic circle 4. Arctic ice sheet begins to form 2.7 mya starting the Ice |
| What are the three signs that the ice age was upon the pliocene? (started 2.7 mya) | 1. there is a gradual decrease in temprature 2. an increase in the variation of climate (more hot an cold more contrasting) 3. the closure of panama |
| During the late tertiary period, during the pliocene what changes can be seen in africa and why are they caused? | Africa is seeing a Big progressive drought. All of the lush forests and woodlands are replaced with savanna and grasslands. Large reduction in vegetation, changes can be seen in the plants some go extinct while a few new, more resistant plants are created. Lucy ancestors dissapear except gelada baboons in the savanna of Africa. |
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