˗ˏˋ fossils ´ˎ˗

Question 1

who is mary anning (1799-1847)?

Answer 1

studied the excavations of fossilized dinosaurs.

Question 2

what does it mean to be extant?

Answer 2

a species that is still living.

Question 3

what is deep time?

Answer 3

• theory by james hutton’s that said the world was much older than biblical explanations allowed
• this age could be determined by gradual natural processes like soil erosion

Question 4

what is continental drift?

Answer 4

• the slow movement of continents over time
• the appalachian mountains (united states) and caledonian mountains (scotland) fit together

Question 5

what is uniformitarianism?

Answer 5

the theoretical perspective that the geologic processes observed today are the same as the processes operating in the past.

Question 6

what is catastrophism?

Answer 6

the theoretical perspective that earth is young and that any changes in the landscape resulted from sudden catastrophic events like volcano eruptions and floods.

Question 7

what are fossils?

Answer 7

mineralized copies of organisms or activity imprints.

Question 8

how old is earth?

Answer 8

• roughly over 4.6 billion years old
• first evidence for a living organism appeared around 3.5 billion years ago (bya)

Question 9

what is a holocene?

Answer 9

the geologic epoch from 10 kya to present.

Question 10

what is an anthropocene?

Answer 10

the proposed name for our current geologic epoch based on human-driven climate change.

Question 11

what is an eon?

Answer 11

the largest subunit of time.

Question 12

what is an era?

Answer 12

eons are divided into them, units of geologic time that span millions to billions of years and that are subdivided into periods and epochs.

Question 13

what periods?

Answer 13

eras are divided into them, units of geologic time that span millions of years and are subdivided into epochs.

Question 14

what are epochs?

Answer 14

periods are divided into them, the smallest unit of geologic time.

Question 15

what is pangea?

Answer 15

• supercontinent that existed during the paleozoic era
• breakup began 200 mya

Question 16

what is the tectonic plate theory?

Answer 16

earth is divided into plates that are capable of movement.

Question 17

what is taphonomy?

Answer 17

• the study of what happens to an organism after death
• provides insight into culture and evolution
• deliberate burials often include the body placed in a specific position, such as supine (on the back) with arms crossed over the chest or in a flexed position (think fetal position) facing a particular direction
• if bones have evidence of a carnivore or rodent gnawing on them, it can be inferred that the remains were exposed to scavengers after death

Question 18

what are bog bodies?

Answer 18

• bodies preserved in the peaty, waterlogged bogs, typically in northern europe
• anaerobic (oxygen-free environment)
• peat bogs are rich in acids and low in oxygen

Question 19

what are ice mummies?

Answer 19

a specimen of human remains that is naturally mummified by extreme low temperatures (i.e.: otzi).

Question 20

what is fossilization?

Answer 20

the process by which an organism becomes a fossil (soft tissues decay while the bones and teeth are preserved).

Question 21

what is sediment accumulation?

Answer 21

• provides the pressure needed for mineralization to take place.
• includes lithification (pressure of sediments squeeze extra water out of decaying remains and replace the voids that appear with minerals from the surrounding soil and groundwater)
• also includes permineralization (when minerals from water impregnate or replace organic remains, leaving a fossilized copy of the organism)

Question 22

what are plant fossils?

Answer 22

includes fern, petrified wood.

Question 23

what are human/animal fossils?

Answer 23

fossils of humans or animals.

Question 24

what are asphalt fossils?

Answer 24

• sticky, black, highly viscous liquid or semi-solid form of petroleum
• la brea tar pit
• can trap megafauna (large animals)

Question 25

what role does igneous rock play in fossils?

Answer 25

• rocks that form when magma (molten rock) cools and crystallizes
• although most fossils are found in sedimentary rock, it is possible for fossils to be in this type of rock

Question 26

what are trace fossils?

Answer 26

• fossilized remains of activity such as footprints
• laetoli footprints (found in tanzania, early hominin footprints (3.6 mya), three hominins walked across, australopithecus afarensis (lucy and friends), walked across wet volcanic ash, were probably bipedal, modern gait, short stride, possible family organization.

Question 27

what are pseudofossils?

Answer 27

natural rocks or mineral formations that can be mistaken for fossils.

Question 28

what is relative dating?

Answer 28

dating methods that do not result in numbers of years but, rather, in relative timelines wherein some organisms or artifacts are older or younger than others.

Question 29

what is stratigraphy?

Answer 29

• relative dating method that is based on ordered layers or (strata) that build up over time
• biostratigraphy (uses other plant and animal remains occurring in the stratigraphic context to establish time depth)

Question 30

what is the law of superposition?

Answer 30

scientific law that states that rock and soil are deposited in layers, with the youngest layers on top and the oldest layers on the bottom.

Question 31

what is cultural dating?

Answer 31

relative dating method that arranges human-made artifacts in a time frame from oldest to youngest based on material, production technique, style, and other features.

Question 32

what is fluorine dating?

Answer 32

relative dating method that analyzes the absorption of fluorine in bones from the surrounding soils; a type of chemical dating.

Question 33

what is piltdown man?

Answer 33

• in 912, charles dawson of england “discovered” him (eoanthropus dawsoni)
• claimed to be the “missing link” between humans and apes
• ckull had a large bulbous cranium like modern humans, but a primitive apelike jaw and teeth
• accepted as scientifically accurate for 40 years; disproved in 1953
• created out of: 2-3 medieval humans and the jaw from a modern bornean orangutan, pongo pygmaeus

Question 34

what is chronometric dating?

Answer 34

dating methods that give estimated numbers of years for artifacts and sites.

Question 35

what are atoms?

Answer 35

smallest building block of matter.

Question 36

what are stable isotopes?

Answer 36

• variants of elements that do not change over time without outside interference
• can be unstable (variants of elements that spontaneously change into stable isotopes over time)

Question 37

what is radioactive decay?

Answer 37

the process of transforming the atom by spontaneously releasing energy.

Question 38

what is radiocarbon dating?

Answer 38

• the chronometric dating method based on the radioactive decay of 14C in organic remains
• 4N + cosmic rays converts into 14C
• 14C absorbed by plants during photosynthesis
• 14C has a half-life of 5,730 years
• 14C can only be used on remains of biological organisms

Question 39

what is potassium-argon (K-Ar) dating?

Answer 39

a chronometric dating method that measures the ratio of argon gas in volcanic rock to estimate time elapsed since the volcanic rock cooled and solidified.

Question 40

what is fission track dating?

Answer 40

a chronometric dating technique based on analyses of the damage trails, or tracks, left by fission fragments in certain uranium-bearing minerals and glasses.

Question 41

what is luminescence dating?

Answer 41

the chronometric dating method based on the buildup of background radiation in pottery, clay, and soils.

Question 42

what is dendrochronology?

Answer 42

a chronometric dating method that uses the annual growth of trees to build a timeline into the past.

Question 43

what is amino acid racemization?

Answer 43

a chronometric dating method that measures the ratio of l-form to d-form amino acids in shell, bone, and teeth to establish elapsed time since death.

Question 44

what is paleomagnetic/geomagnetic reversal?

Answer 44

periods in earth’s history when magnetic north and south move significantly from their current positions.

Question 45

what are sediment cores?

Answer 45

core samples taken from lake beds or other water sources for analysis of their pollen.

Question 46

what is diet environmental reconstruction?

Answer 46

• stable isotope analysis (bones and teeth)
• plants: carbon analyses
• ratios of stable nitrogen isotopes

Question 47

what is migration environmental reconstruction?

Answer 47

• isotopic signatures
• information on where individuals lived

Question 48

who is naia?

Answer 48

• yucatán peninsula, mexico
• 15-16 yr old female
• 11,000 years ago, know this from radiocarbon dating of her tooth enamel
• poor nutrition
• injury (healed spiral fracture of her left forearm)
• skeleton is incomplete, it is more complete than any other “new world skeleton” ever found.