Paleozoic Life History - INVERTEBRATES

Question 1

This was the time when animals with skeletons appeared abruptly in the fossil record, described as an explosive development of new types of animal

Answer 1

Cambrian Explosion

Question 2

What is the factor that enabled the animals to produce their shells during the Neoproterozoic and Early Cambrian?

Answer 2

Increase concentration of Calcium

Question 3

The increase in the concentration of calcium allowed the precipitation of what compounds that produced the shells of most invertebrates?

Answer 3

Calcium Phosphate and Calcium Carbonate

Question 4

Four advantages of an Exoskeleton or Shell

Answer 4

1. Provides protection against UV Radiation
2. Helps prevent drying out in intertidal environments.
3. Allows animals to increase their size.
4. Provides protection against predators.

Question 5

TRUE OR FALSE?

Scientists currently have a clear answer and understanding as to why Marine organisms evolved mineralized skeletons during the Cambrian explosion and shortly thereafter.

Answer 5

FALSE, they do not have a clear answer.

Question 6

Group of organisms that live in the water column

Answer 6

Pelagic

Question 7

Pelagic organisms that are referred to as the FLOATERS

Answer 7

Plankton

Question 8

Pelagic organisms that are referred to as the SWIMMERS

Answer 8

Nekton

Question 9

Plant Planktons

Answer 9

Phytoplankton

Question 10

Animal Plankton

Answer 10

Zooplankton

Question 11

Enumerate two examples of a Phytoplankton

Answer 11

Diatoms
Dinoflagellates

Question 12

Enumerate three examples of Zooplankton

Answer 12

Foraminifera
Radiolarians
Jellyfish

Question 13

Enumerate two examples of Nekton Organisms

Answer 13

Fish
Cephalopods

Question 14

Group of organisms that live on or in the Seafloor

Answer 14

Benthos

Question 15

Benthos organisms that live ON the seafloor are characterized as _________ and ________

Answer 15

Epifauan (animals)
Epiflora (plants)

Question 16

Benthos organisms that live IN the seafloor are characterized as ___________ and __________

Answer 16

Infauna (animals)
Inflora (plants)

Question 17

A subgroup based on movement of Benthos organisms that stay in one place

Answer 17

Sessile

Question 18

A subgroup based on movement of Benthos organisms that move around on or in the seafloor

Answer 18

Mobile or Vagrant

Question 19

A feeding group that removes or consume microscopic plants and animals as well as dissolved nutrients from the water

Answer 19

Suspension-feeding animals

Question 20

A feeding group characterized as plant eaters

Answer 20

Herbivores

Question 21

A feeding group characterized as meat eaters

Answer 21

Carnivores-Scavengers

Question 22

A feeding group that ingests sediments and extracts the nutrients from it

Answer 22

Sediment-deposit feeders

Question 23

The Cambrian period was also known as the “_______ ___ ___ ___________” and the “_________ ___ ___ ___________”

Answer 23

“Age of the Invertebrates” and “Golden Age of Trilobites”

Question 24

The by far most conspicuous element of the Cambrian marine invertebrate community and made up approximately half of the total
fauna.

Answer 24

Trilobites

Question 25

They are an extinct class of arthropods and the most sought-after invertebrate fossils.

Answer 25

Trilobites

Question 26

The Trilobites lived from _______ ________ until the end of the __________.

Answer 26

Early Cambrian until the end of the Permian

Question 27

Trilobites were most diverse during the _____ ___________.

Answer 27

Late Cambrian

Question 28

Shell organisms that are characterized as benthic, sessile, and suspension-feeders.

Answer 28

Brachiopods

Question 29

The most common or abundant type of Brachiopods

Answer 29

Inarticulate Brachiopods

Question 30

Brachiopods secrete a _________________ shell composed of the organic compound chitin combined with calcium phosphate.

Answer 30

Chitinophosphate

Question 31

Similar to Brachiopods, this major group of Cambrian Organisms were benthic, sessile, suspension-feeders that constructed reef-like structure

Answer 31

Archaeocyathids

Question 32

A lagerstatten that contains important fossils of the Paleozoic and represents one of the most significant fossil finds of the 20th century consisting of carbonized impressions of soft-bodied animals and plants.

Answer 32

Burgess Shale Biota

Question 33

A Carnivorous worm

Answer 33

Ottoia

Question 34

A scaly, armored slug-like creature

Answer 34

Wiwaxia

Question 35

A Velvet worm

Answer 35

Hallucigenia

Question 36

An arthropod

Answer 36

Waptia

Question 37

A period characterized by the adaptive radiation of many other animal phyla (such as articulate brachiopods, bryozoans, and corals),

Answer 37

Ordovician

Question 38

Organic-walled phytoplankton that increased in diversity and abundance during the Ordovician that still exists today

Answer 38

Acritarchs

Question 39

The dominantly top predators during the Ordovician

Answer 39

Nautiloids

Question 40

A subclass of cephalopods that evolved from nautiloids during the Early Devonian

Answer 40

Ammonoids

Question 41

Planktonic organisms carried by ocean currents that are excellent guide fossils because most of their species existed for less than a million years.

Answer 41

Graptolites

Question 42

A group of well-known, small, tooth-like fossils that was probably an elongate swimming organism.

Answer 42

Conodonts

Question 43

What mineral is conodont fossils made up of?

Answer 43

Apatite (Calcium Phosphate)

Question 44

The first known major and 2nd largest Mass Extinction

Answer 44

Ordovician-Silurian Mass Extinction

Question 45

The Ordovician-Silurian Mass Extinction is also known as?

Answer 45

Hirtnanian-Rhuddanian Mass Extinction

Question 46

What is the percentage casualty on all the Marine and Land Species in the Ordovician-Silurian Mass Extinction?

Answer 46

85%

Question 47

What is the percentage casualty on all the Marine Invertebrates in the Ordovician-Silurian Mass Extinction?

Answer 47

60%

Question 48

How many Brachiopods and Bryozoans died in the Ordovician-Silurian Extinction?

Answer 48

2/3

Question 49

What caused the Ordovician-Silurian Mass Extinction

Answer 49

Plate movements resulting in a changing global geography and extreme climate change

Question 50

Two Phases of the Ordovician-Silurian Mass Extinction

Answer 50

a. Affecting graptolites, brachiopods, and trilobites. b. Occured as sea levels fell because of the onset of glaciation in Gondwana.