Deck 12: Paleozoic Life History Invertebrates

Question 1

Trilobites make excellent guide fossils.

Answer 1

True

Question 2

The first evidence of shelled organisms is calcareous tubes found with the Ediacaran fauna.

Answer 2

True

Question 3

The three differentiated components of a trilobite are the cephalon, the thorax, and the pygidium.

Answer 3

True

Question 4

Devonian mass extinctions were partly caused by global tectonic changes as the collision of continents reduced the amount of shallow marine shelf environment.

Question 5

The Burgess Shale is significant because it contains mostly soft-bodied fossils.

Question 6

Pelagic organisms live in the water column above the seafloor.

Question 7

Burrowing worms are examples of planktonic organisms.

Question 8

Plankton are small animals and plants that float passively in the marine environment.

Question 9

The ammonoids are excellent guide fossils because of distinctive physical features, short species ranges, and a wide geographic distribution.

Question 10

The end-Devonian mass extinction affected polar and high-latitude organisms the most.

Question 11

There is no evidence in the geologic record that multicellular organisms of any kind existed prior to the Cambrian.

Question 12

A worm that burrows into sediments below the sediment-water interface is a part of the epifauna.

Question 13

All of the organisms that live on or in the seafloor are part of the benthos.

Question 14

Invertebrates are defined as animals with shells.

Question 15

Organisms that comprised reef complexes remained virtually unchanged during the Paleozoic.

Question 16

The Burgess Shale was deposited during the Cambrian as the Sauk Sea transgressed onto the craton.

Question 17

Pelagic fish are part of the benthos.

Question 18

Ammonoids, graptolites, and conodonts are excellent guide fossils because of their short stratigraphic ranges and wide geographic ranges.

Question 19

Invertebrates are a group of organisms that have backbones.

Question 20

Phytoplankton are primary producers.

Question 21

Planktonic foraminifera and jellyfish are examples of zooplankton.

Question 22

An organism classified as an autotroph has which of the following characteristics?

A) It is a carnivore.
B) It produces its own food.
C) It is a guide fossil.
D) It is an herbivore.
E) It is a scavenger. It is at the bottom of the food chain

Question 23

Diatoms and algae are examples of phytoplankton.

Question 24

From a human time perspective, most mass extinctions would appear to ____.

A) have occurred rapidly
B) have  occurred gradually
C) are immediately recognizable
D) involve a complete wipeout of all living organisms
E) have  only occurred in marine environments

Question 25

Any animal that eats other animals, living or dead, as a source of nutrients is a(n) ____.

A) ectotherm
B) endotherm
C) suspension feeder
D) carnivore-scavenger
E) herbivore

Question 26

The Cambrian explosion refers to ____.

A) a meteorite impact
B) a sudden appearance of fossils
C) a sudden extinction
D) the start of evolution
E) volcanism that created the Ring of Fire

Question 27

Shallow water fauna and phytoplankton are stressed during glaciations due to ____.

A) rising sea levels
B) warming surface waters
C) changing isotope ratios
D) lower sea levels
E) reduced sunlight

Question 28

Archaeocyathid, bryozoan, and stromatoporoid fossils indicate which type of environment?

A) deep sea
B) tidal flats
C) delta
D) lake
E) reef

Question 29

Trilobites, an abundant organism during the Early Paleozoic and less abundant during the Late Paleozoic, survived to the Cenozoic.

Question 30

All bottom-dwelling marine organisms that live on the seafloor or within seafloor sediment are ____.

A) anomalocaris
B) benthos
C) nektons
D) chordates
E) ammonoids

Question 31

Mass extinctions at the end of the Ordovician occurred because of ____.

A) dramatic changes related to glaciation
B) dramatic chemical changes in seawater related to meteorite impact
C) increased solar radiation
D) increased sea levels
E) increased volcanism

Question 32

Organisms that move on the seafloor are called ____, while organisms that do not move are called ____.

A) articulate; inarticulate
B) articulate; stationary
C) mobile; sessile
D) sessile; inarticulate
E) articulate; sessile

Question 33

In the marine ecosystem, a shark would be classified as an infaunal and benthic organism.

Question 34

The extinction event at the end of the Permian affected only land-dwelling organisms.

Question 35

Which group feeds on microscopic plants, animals, and nutrients in water?

A) herbivores
B) carnivores
C) sediment-deposit feeders
D) suspension feeders
E) inhalation feeders

Question 36

Which characteristic does not apply to trilobites?

A) abundant in modern oceans
B) excellent guide fossils
C) benthos, mobile
D) compound eyes
E) invertebrate

Question 37

Three of the five largest mass extinctions occurred at the end of the ____.

A) Cambrian, Devonian, and Mississippian
B) Ordovician, Silurian, and Devonian
C) Ordovician, Devonian, and Permian
D) Silurian, Devonian, and Permian
E) Cambrian, Devonian, and Permian

Question 38

Greatly accelerated extinction rates resulting in marked decrease in biodiversity are ____.

A) transgressions
B) regressions
C) mass extinctions
D) evolutionary nonstarters
E) evolutionary starters

Question 39

An extinct group of arthropods with a body divided into three lobes is a(n) ____.

A) crinoid
B) acritarch
C) organelle
D) trilobite
E) echinoid (echinoderm)

Question 40

The unique preservation of soft-bodied fauna in the Burgess Shale occurred because ____.

A) animals and plants were carried by turbidity flows to aerobic deep-sea conditions
B) animals and plants were transported and buried in anaerobic conditions
C) scavenging  bacteria were able to destroy organisms at the burial site
D) predators consumed their soft parts, leaving the hard part behind
E) animals with hard parts were deposited immediately above the shale

Question 41

Benthic plants that live on the seafloor are called ____________________ and benthic animals that live on the seafloor are called ____________________.

Question 42

Organisms that belong to the benthos are classified primarily by ____.

A) where they live
B) where they live and how they reproduce
C) how they reproduce and if they move
D) life span and place in food chain
E) where they live and place in food chain

Question 43

A stratified ocean in the Late Permian could have been caused by ____.

A) global warming
B) global cooling
C) increased  ocean circulation
D) increased downwelling
E) decreasing population of trilobites

Question 44

Plankton and nekton are different because ____.

A) plankton are pelagic, while nekton are not
B) plankton are carnivorous, while plankton are not
C) plankton float, while nekton do not
D) nekton float, while plankton do not
E) nekton are benthic, while plankton are not

Question 45

The most likely way volcanic activity could have directly contributed to the Permian mass extinction is by ____.

A) destroying habitat
B) raising local temperatures
C) inhibiting rain fall
D) killing primary consumers
E) releasing poisonous gases

Question 46

Flood basalts from the ____________________ ____________________ could have depleted ozone levels and contributed to the Permian mass extinction.

Question 47

The ____________________ ____________________ provides paleontologists with a unique look at the soft-bodied organisms that thrived in the Middle Cambrian.

Question 48

____________________ make their own food.

Question 49

Benthic organisms that move through or live in the sediment are called ____________________.

Question 50

Pelagic organisms can be divided into floaters, called ____________________, and swimmers, called ____________________.

Question 51

If you were transported back in time to the Cambrian Period, the mobile marine organisms that would be most unique to that period would be ____.

A) brachiopods
B) crinoids
C) sharks
D) trilobites
E) plankton

Question 52

The Great Biodiversification Event occurred during the ____.

A) Ordovician
B) Silurian
C) Devonian
D) Mississippian
E) Permian

Question 53

The ____________________ are tooth-like calcium phosphatic fossils that are excellent index fossils for the Ordovician.

Question 54

The different tiers of food production and consumption in an ecosystem within a feeding hierarchy are called ____________________ ____________________.

Question 55

How can we classify phytoplankton within a food web?

A) decomposer
B) primary consumer
C) primary producer
D) secondary consumer
E) secondary producer

Question 56

The mass extinction in the geologic record, which proved to be the most devastating to life on Earth, occurred at the end of the ____.

A) Cambrian
B) Cretaceous
C) Devonian
D) Ordovician
E) Permian

Question 57

Bacteria break down dead organisms into organic compounds. Therefore, they function as ____________________ in the food web.

Question 58

Jellyfish are ____.

A) pelagic plankton
B) benthic plankton
C) benthic nektons
D) pelagic nektons
E) pelagic articulates

Question 59

Animals that ingest sediment and extract the nutrients from it are called _________________________.

Question 60

The Permian extinction killed approximately ____ of all marine invertebrate species.

A) 54%
B) 66%
C) 70%
D) 83%
E) 96%

Question 61

In Charles Darwin's day, the fossil record began abruptly with the appearance of shelled organisms. Today, we consider the same period-the Cambrian-as an "explosion" of life forms. Why has this perspective changed?

Question 62

Describe the Burgess Shale environment and biota. What controversies are presently part of the discussions of this biota?

Question 63

Why are the Burgess Shale organisms considered an unusual fossil assemblage?

Question 64

Scientists have several hypotheses for why the Cambrian explosion occurred. Explain three of the hypotheses.

Question 65

Discuss how Silurian and Devonian reefs differed from Cambrian reefs.

Question 66

Describe four ways shells can benefit animals.

Question 67

Describe and discuss the marine communities of the Ordovician, Silurian, and Devonian. How do they compare with present-day marine communities?

Question 68

Describe the components of the present-day marine ecosystem. What types of organisms populate this ecosystem? Give specific examples.

Question 69

Describe and discuss mass extinctions during the Paleozoic and Mesozoic. How do these mass extinctions differ?

Question 70

Consider an early reef-builder of the Cambrian, the archaeocyathid. Using correct terminology for marine ecosystems, classify this organism on where it lives, how it gets around, and how it feeds. How does the lifestyle of archeocyathids compare with that of Cambrian trilobites?