exam 4 Flashcards
what is the definition of fossils
trees and remains of ancient organisms
the remains of once living organisms
what are the conditions for fossilization
not exposed
buried quickly
oxygen free
where scavengers cannot access & bacteria free
what are conditions that will NOT lead to fossilization
remains are left exposed for a long period of time
because scavengers will eat
and maggots will quickly consume the flesh
what are some examples of of ways that an organisms can be buried quickly upon death
under soil sediments deposited by water
how is the geological timescale information obtained?
By placing all past life forms - as rep. by organisms - on the geographical timescale - paleo’s record major changes and events in the evolution of plants and animals
what is stratigraphy
Stratigraphy is a branch of geology concerned with the study of rock layers and layering. It is primarily used in the study of sedimentary and layered volcanic rocks.
what is the geological timescale
Geologic Time Scale, also often known as GTS, is a method of determining when certain animals lived and their relationships to each other by examining rock layers and the fossils they contain.
when was the cenozoic era?
65 mya
what are the 7 epochs within the cenozoic era?
These are the 7 epochs within the cenozoic era and in order
1 - Holocene
2 - Pleistocene
3 - Pliocene
4 - Miocene
5 - Oligocene
6 - Eocene
7 - Paleocene
what are the two types of fossils
sedimentary ( common)
volcanic rock
holocene time frame in book
0 - 0.12 million years
pleistocene timeframe
0.12 million years - 2.6 million years
pliocene timeframe
2.6 - 5.3 million years
Miocene timeframe
5.3 - 23 million years
Eocene
34 - 56 mya
paleocene
56 - 66 mya
who is the first recognized tool user?
austrolopithecus garhi
what is cenozoic
era lasting from 66 mya until the present encompassing the radiation and proliferation of mammals such as humans and other primates
what is mesozoic
second major era of geologic time, 230 - 66 mya, characterized by the emergence and extinction of dinosaurs
what is paleozoic
first major era of geologic time, 545 - 66 mya, characterized by the emergence and extinction of dinosaurs
what is the criteria for radiometric dating
The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay.
what is characteristics define a hominin
bipedal locomotion
nonhoning chewing
preceded speech
material culture
what are the 7 distinguishing characteristics that are associated with bipedalism in the skeleton
foramen magnum is positioned on the bottom of the skull
the spine is s shaped
ilium is short from frornt to back
legs are long relative to the body trunk and arms
knees are angled inward
foot has a longitudinal arch
big toe is not opposable
what is the difference between honing and nonhoning chewing
primates have honing chewing, which means their large canines cut their food
what makes a hominin a hominin
nonhoning chewing
bipedal locomotion
what are anatomical characteristics of bipedalism
foramen magnum on the bottom of the skull
s-shaped spine
short pelvis front to back
long legs
knees angled torward midline of the body
double-arched foot , including a well-developed longitudinal arch
nonopposable big toe
what are anatomical characteristics of nonhoning chewing
blunt, nonprojecting canine
small canine relative to size of other teeth
no diastema
wear on tips of canines and of third premolars
cusps on lower third premolar equal size
early hominins - WHEN?
7mya - 1 mya
early hominins - WHERE
Restricted to africa
early hominins - WHO?
Sahelanthropos - s. tchadensis - biped. det. by f.m. this was 7 mya, lived in the forested, humind, chad, NC Africa, 350cc
Orrorin - o.tugensis - 6 mya, femur bones, east africa, forested environment
Ardipiethecus - ar. ramidus - 4.4 mya, 350 cc, ethiopeia, forested env.
Australopithecus - Au. farensis - laetoli, footprints, “lucy”, 3.6 til 3 mya , dikika
& Au garhi also under australopithecus
what are the 2 hypotheses related to the evolution of bipedalism
patchy forest hypothesis
owen lovejoy provisioning hypothesis
reivew patchy forest hypothesis
human origins & bipedalism related to the greater efficiency in some habitats of moving on 2 limbs rather than 4
bipedalism arose in areas where forests were fragmented & food resources also became scathed
as forests, fragmented bipedalism freed the hands to pick up food allowing both tree and ground food resources to be exploited
review the owen love joy provisioning hypothesis
freeing hands was in important in allowing males to assist females more efficiently in processing food; thus “ provisioning” acted as a form of sexual competitions among males for females
birth species would also be reduced , since females would have to move around less & would have access to greater food resources
love joy’s hypothesis makes the argument for monogamous fathers
organize information on early hominins by using australopithecus afarensis as a point of reference
PRE AUSTRALOPITHECUS IS FIRST
IN THAT CATEGORY THERE IS - Sahelantropus tchadensis, orrorin tugenesis, ardipithecus, and australopithecis anamensis
OK THEN IT IS AUSTRALOPITHECUS AFARENSIS
later one there are more derived hominins such as-
Africanus, paranthropines (these are rubust australopithecines - A. aethiopicus, A. boisei, A. robustus)
LAST IS THE EARLY HOMO (H. habilis)
what are the dates, cranial capacities, and areas in which sahelanthropus tchadensis are found
LOCATION - central africa
CRANIAL CAPACITY - 350 CC
DATE - 7-6 Mya
what are the dates, cranial capacities, and areas in which orrorin tugenesis are found
LOCATION - Near lake turkana (book says djurab dester, chad)
DATE- 6mya
CRANIAL CAPACITY -
what are the dates, cranial capacities, and areas in which ardipithecus are found
LOCATION - Ethiopia (W. AFRICA)
DATE - 5.8 - 4.4 mya
CRANIAL CAPACITY -
how was bipedalism determined for sahelanthropus tchadensis
based on the position of the foramen magnum at the base of the skull
and
the canine premolar chewing complex was nonhoning
how was bipedalism determined for orrorin tugenesis
found several partial femurs each missing the knee indicating that they were bipedal
how was bipedalism determined for ardipithecus
lacked flexibility required for grasping tree limbs and moving through trees
musculature and construction of adri’s foot were rigid
(hominin adaption for using the foot to propel itself forward when walking bipedally)
what are considered the robust australopithecines
A. afarensis,
A. africanus,
Paranthropus
characteristics in relation to diet for a. afarensis
more diverse diet than its predecessors
generally speaking what are the characteristics in relation to diet for robust australopithecines
chewed tough foods
significant amount of low quality vegetations
how did the australopithecine lineage leading to homo adapt its diet to prevent extinction?
developing a flexible and generalized diet
omnivorse
characteristics in relation to diet for h.habilis
omnivorse, variety diet
meat, hard foods, leaf & fruit
what are the benefits of the patchy forest environment
Energy efficiency
Carrying with two hands
Vigilance
Heat Dissipation
Display - appear to be larger
at what stage in Homo evolution does the patchy forest hypothesis become relevant
A. Afarensis
what are stone tools associated with
meat consumption
wearing on stone tools indicated what…
they were using for digging
what is the environmental context that explained the adaptive benefits of bipedalism
patchy forest environment
what is strata
layers of rock representing various periods of deposition
Miocene
earliest major worldwide division of the Neogene Period (23 million to 2.6 million years ago) that extended from 23 million to 5.3 million years ago, a time when land-dwelling mammals were essentially modern.
Pliocene
the epoch in the geologic timescale that extends from 5.333 million to 2.58 million years BP. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch.
Pleistocene
the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the world’s most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology.
Plio-Pleistocene
The Pliocene and Pleistocene epochs are commonly combined and referred to as the Plio-Pleistocene because of their short duration in comparison to previous epochs, and also because the events that took place during these epochs are very closely associated.
Holocene
The Holocene is the current geological epoch. It began approximately 11,650 cal years before present, after the last glacial period. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1, and is considered by some to be an interglacial period.
mold
Any of various filamentous fungi that grow on and contribute to the decay of organic matter.
cast
to receive form in mold?
taphonomy
Taphonomy is the study of how organisms decay and become fossilized. The term taphonomy was introduced to paleontology in 1949 by Russian scientist Ivan Efremov to describe the study of the transition of remains, parts, or products of organisms from the biosphere to the lithosphere.
paleospecies
The species that are given ancestor and descendant status in a phyletic lineage, depending on the geological strata in which they are found.
Paleospecies is a species defined by fossil evidence often covering a long time period.
fluorine dating
relative chemical dating method that compares the accumulation of fluorine in animal and human bones from the same site
superposition
superposition principle, also known as superposition property, states that, for all linear systems, the net response caused by two or more stimuli is the sum of the responses that would have been caused by each stimulus individually.
relative dating
Relative dating is the science of determining the relative order of past events, without necessarily determining their absolute age,. In geology, rock or superficial deposits, fossils and lithologies can be used to correlate one stratigraphic column with another.
chronometric dating
Chronometric dating, also known as chronometry or absolute dating, is any archaeological dating method that gives a result in calendar years before the present time. Archaeologists and scientists use absolute dating methods on samples ranging from prehistoric fossils to artifacts from relatively recent history.
radiometric dating
Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay.
plate tectonics
Plate tectonics is a scientific theory describing the large-scale motion of seven large plates and the movements of a larger number of smaller plates of the Earth’s lithosphere, since tectonic processes began on Earth between 3 and 3.5 billion years ago.
hominins
The Hominini, or hominins, form a taxonomic tribe of the subfamily Homininae. Hominini includes genus Homo, but excludes genus Goril
what is postcranial
Situated behind the cranium.
adj. Consisting of the parts or structures behind the cranium.
adj. Relating to the portion of a vertebrate skeleton located behind and/or beneath the cranium.
habitual bipedalism
Habitual bipedalism, or obligate bipedalism, is rare. This is the form of bipedalism that is assumed as a regular (i.e., habitual) means of locomotion. Today, very few mammals (e.g., humans and kangaroos) demonstrate habitual bipedalism.
foramen magnum
The foramen magnum (Latin: great hole) is a large oval opening in the occipital bone of the skull in humans and various other animals.It is one of the several oval or circular openings (foramina) in the base of the skull.
occipital condyles
The occipital condyles are undersurface protuberances of the occipital bone in vertebrates, which function in articulation with the superior facets of the atlas vertebra.
sagittal crest
A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are exceptionally strong jaw muscles.
LINE ALONG THE TOP CHAKRA
zygomatic arch
The zygomatic arch, or cheek bone, is formed by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone, the two being united by an oblique suture; the tendon of the temporalis passes medial to the arch to gain insertion into the coronoid process of the mandible.
where is homo habilis found
africa
where is homo erectus found
africa, asia, europe
homohabilis cranial capacity
700 c.c.
homo erectus cranial capacity
900 c.c.
date of homo habilis?
2.5 - 1.8 mya
date of homo erectus
1.8 mya - 400,000 ya
which is recent, habilis or erectus
erectus
what is the average cc of a erectus
900cc
cranial capacities of homo erectus
750 cc - 1250 cc
what are the trends that characterize the genus Homo in contrast to the other hominins
larger brain
tool use
smaller back teeth
decrease relative face size
3 criteria for determining whether rocks found in assemblages are tools
Regularity in shape
Tools found in association with animal bones
considerable distance from the source of material
why homo habilis instead of australopithecus
Larger brain size - from 408 cc to 680 cc
and up to 800cc in one specimen
STONE TOOLS - higher thought complexity
why did homo erectus migrate out of africa
ice ages
culture as a strategy of adaptation: emphasis on tools
the environment in the pleistocene
ice age
which characteristics were present in the earliest hominins
bipedalism
which skeletal characteristic is not associated with the hominin evolution of bipedalism
a varus knee
what skeletal characteristics are associated with bipedalism
foramen magnum on bottom of skull
shortened pelvis
a varus knee
s-shaped spine
which characteristic is not a hominin adaption
thin tooth enamel
pre-australopithecines are distinguished from apes by both bipedalism and by
an intermediate or complete loss of the honing complex
when did the acheulian tradition- of bifacial hard axes appear
1.4 mya
Lower Paleolithic began when
25 mya
species in lower paleolithic
au. garhi
H. Habilis
tools used in the lower paleolithic
oldowan tools ("flakes)
simple cores, flaked pieces, and later large bifacestools in upper paelo
tool shapes and source materials (now also a lot of bone, antler, and ivory), which in some areas was carried on beyond the end of the last ice age all the way
blade tools made of stone were still created, too. Sewing was now definitely within the realm of possibility, and spear throwers, harpoons, and bows and arrows
when was upper paleolithic
(c. 50,000/40,000- c. 10,000 years ago
species in the upper paleo
homo sapiens
date of middle paleolithic
(c. 250,000- c. 30,000 years ago)
fire & language first used in what stone tool period
middle paleolithic
species in middle paelo
Associated humans are most prominently the Neanderthals (Mousterian industry) but also early Homo sapiens.
middle paleolithic AKA
mousterian/ Levallois
upper paleo AKA
material and symbolic culture of H Sapiens
lower paleo AKA
oldowan- Acheulian
what are the benefits that result frm the control of fire by homo erectus
heat, protection from animals,
cook food
light & extension of human activity
llevallois technique
a name given by archaeologists to a distinctive type of stone knapping developed by precursors to modern humans during the Palaeolithic period.
pointy spears!
oldowan tools
Oldowan technology is typified by what are known as “choppers.” Choppers are stone cores with flakes removed from part of the surface, creating a sharpened edge that was used for cutting, chopping, and scraping (image 1985–0235).
mousterian tradition
an advance over the Acheulean tradition in that Mousterian tools are typically flakes, produced from cores that are meticulously pre-processed with the clear intent of shaping them to produce optimal flakes. This permitted a smaller amount of stone to produce a far longer total cutting edge, and the flake tools so created gradually displaced the older and less efficient hand axes for most purposes. This kind of core preparation is referred to as the “Levallois” (lev-all-WA) technique.
Core
core tools are the largest; the earliest and most primitive were made by working on a fist-sized piece of rock (core) with a similar rock (hammerstone) and knocking off several large flakes on one side to produce a jagged but sharp crest.
Flake
a flake tool is a type of stone tool that was used during the Stone Age that was created by striking a flake from a prepared stone core. … Stone is able to break apart when struck near the edge. Flake tools are created through flint knapping, a process of producing stone tools using lithic reduction.
occipital bun/ nuchal torus
An occipital bun is a prominent bulge or projection of the occipital bone at the back of the skull. It is important in scientific descriptions of classic Neanderthal crania. While common among many of humankind’s ancestors, primarily robust relatives rather than gracile, the protrusion is rare in modern Homo sapiens
browridge
a nodule or crest of bone situated on the frontal bone of the skull. It forms the separation between the forehead portion itself (the squama frontalis) and the roof of the eye sockets
post orbital constriction
In physical anthropology, post-orbital constriction, often referred to as the post-orbital constriction index, is a narrowing of the cranium just behind the eye sockets, in primates — including primitive hominids.
shovel shaped incisors
incisors whose lingual surfaces are scooped as a consequence of lingual marginal ridges, crown curvature or basal tubercles, either alone or in combination.
acheulian tradition/ bifacial hand axe
Acheulean” (ash-you-LEE-un) is taken from the name of a site named Saint-Acheul, near Amiens in northern France, and is used to refer to a range of Lower Paleolithic tool-making traditions found widely across Afro-Eurasia. The typical tool is a general-purpose hand-ax.
the earliest hominins which are classifedd as homoerectus date to as far back as about
1.8 million years ago
what is the earliest example of the genus homo
homohabilis
genus homo differs from australopithecus in that
it has greater cranial capacity and no sagital crests
and that there are smaller premolars and molars
what is the earliest species found outside of africa
HOMO ERECTUS
oldest likely member of the genus homo was found in _____ and is dated to around ____
east africa, 2.5 million B.P.
lower paleolithic began about
2.6 million years ago with the use of stone tools
environment type that characterized africa at the time of the appearance of the first hominins
FOREST
type of climactic paterns present during H. erectus/ergaster evolution
ICE AGE
