Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Intro to Earth Science > C-Rise of the Animals > Flashcards

C-Rise of the Animals Flashcards

(51 cards)

Start Studying
1
Q

What occurred after the GOE?

A

Nothing for 1 billion years (from 1.7bya until around 750mya)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What were Ediacara biota?

A

The oldest unequivocal animal fossils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

After the GOE and before the Cambrian explosion there is fossil evidence for key biological innovations. What were these? (5)

A

Colonial organisms
Macroscopic organisms (Grypania)
Eukaryotic cells (Bangiomorpha, 1.2 Ga), (Ediacara biota)
Multicellularity (Bangiomorpha, 1.2 Ga)
None of these could be interpreted as an animal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the importance of bangiomorpha?

A

1st known sexually reproducing organism

Red alga - complex multicellular (eukaryotic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When was the Cambrian explosion? (supposedly?)

A

540 mya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does radiata mean?

A

Radial symmetry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does bilateria mean?

A

Bilateral symmetry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name the 2 categories of diploblastic radiata.

A

Cnidarians (jellyfish)

Ctenophores (comb-jellies)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name the 2 categories of triplobastic bilateria.

A

Deuterstomes (echnioderms = starfish, sea urchins) (chordates = mammals, birds, reptiles amphibians)
Protostomes (molluscs = snails/octopuses) (arthropods = spiders/insects) (annelids = segmented worms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What category is neither triploblastic or diploblastic (or bilateria or radiata)?

A

Porifera (sponges)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What do diploblastic and triploblastic referto?

A

The number of tissue layers
diploblastic = 2 tissue layers
triploblastic = 3 tissue layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do diploblastic organisms not have?

A

A mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What do the a) ectoderm, b)mesoderm and c) endoderm turn into?

A

a) exoskeleton
b) organs
c) inner lining of organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the Metazoa?

A

All animals with a body composed of cells differentiated into tissues an organs, and usual ya digestive cavity lined with specialised cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the Cambrian Explosion?

A

The sudden appearance of unequivocal animals near the base of the Cambrian

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does the scale of the Cambrian Explosion depend on?

A

Whether fossils in the Ediacaran Period (just before the Cambrian) are animls or not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 3 sources of data of the Ediacaran Period?

A

Possible Ediacaran animal embryos
Ediacaran biotas
Neoproterozoic biomineralised fossils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Neoproterozoic (Ediacaran) biomineralised fossils - a) examples and b) what do they suggest? (look at slide 13)

A

a) Sponge spicules, Cloudina, Namacalathus

b) suggestive or poriferean (sponge) and/or cnidarian (jellyfish) grade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Possible Ediacaran animal embryos -

a) where and how old?

A

Doushantuo Formation, China

600 mya

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Possible Ediacaran animal embryos -

b) what are they replicated in?

A

Huge variety of different types replicated in calcium phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Possible Ediacaran animal embryos -

c) what different interpretations of them are there? (3)

Study These Flashcards
A

Some interpret them as animal embryos - early development stages
Others as resting cysts of animals - resting/dormant stage to survive unfavourable conditions
Others as resting cysts of non-metazoans, and giant bacteria

22
Q

Possible Ediacaran animal embryos -

d) what is odd about them?

Study These Flashcards
A

No juveniles or adults - other stages in life cycle absent

23
Q

What is a scrippsiela trochoidea?

Study These Flashcards
A

A cyst-forming marine plankton (and type of eukaryotic algae) (spiky looking ball)

24
Q

When did Ediacaran biotas exists and what aged rocks were they found in? When do some rare examples occur?

Study These Flashcards
A

Existed in Ediacaran Period
Found in rocks dated between 585-542 Ma
Some rare examples in Phanerozoic

25
What shapes do Ediacaran biotas come in? (slide 19-22)
Different morphologies: enigmatic tubular, discoidal and frond-shaped organisms
26
What is unusual about the preservation of Ediacaran biotas?
Often preserved as moulds of external surfaces
27
Are the Ediacaran biotas well understood?
No, the affinities are hotly debated
28
What are the different interpretations of Ediacaran biotas?
Initial interpretations: focus on them being animals (mawsonites = diploblastic cnidarians (jellyfish)) (Spriggina = arthropod/annelid worm) but absence of diagnostic characteristics New interpretation: part of separate kingdom (Vendobionta - have pneu structure)
29
What structure do Vendobionta have?
A pneu structure (hollow fluid infilled interior)
30
What is taphonomy?
Processes of fossilisation
31
There has been reasonable identity on some Ediacaran biotas and they resemble which trace fossils and what feeding technique?
Kimbrella and Radulichnus (look like slugs) | Grazing trace fossils that feed on the microbial surface of sediment - suggests it is mollusc
32
What is the current understanding of the Ediacaran Period with relation to animals?
Probably a mix of different biological groups, but likely to include biltarians
33
What appears in the Cambrian?
``` Unequivocal examples of Triploblastic bilaterians common from Cambrian onwards Most phyla (phylum) have 1st occurrence in Cambrian ```
34
What sources of data are there for the Cambrian explosion?
Biomineralised tissues of macroscopic remains Small Shelly Fossils Exceptional biotas
35
Give 3 examples of fossilised Cambrian animals.
Echinoderms Trilobites (arthropods) Brachipods (lophophorate)
36
Small shelly fossils - what type of remains are they?
Biomineralised tissues
37
Small shelly fossils - what is there function?
Often their function and affinities are unknown
38
Small shelly fossils - give an example.
Microdictyon (as body) with Cambroclavus as shield and spines on soft-bodied lobopods (from extinct phylum lobopodia) hard parts = biomineralised tissues soft parts = labile tissues
39
Small shelly fossils - the shells had spikes, what does this show?
A need for defence suggests predation
40
Exceptional biotas - when were they common and where?
In early Phanerozoic (especially Cambrian) in marine environments
41
Exceptional biotas - why do some of them have limited preservation potential?
Made solely of highly labile (soft and decay prone) non-biomineralised tissue
42
Exceptional biotas - Case Study - where, when, what, how
In Burgess Shale during Middle Cambrian, in Canada Deeper water setting with series of fossiliferous levels Exceptional biotas buried in situ below depositing event beds Incorporated into depositing event beds
43
Why are Exceptional biotas a valuable source of data on biodiversity?
Allow inferences as regards ecological structure of marine communities
44
Exceptional biotas - examples and ecological strategies - Olenoides (slide 29)
Spines on limbs used for capturing and shredding prey Chitin protein - protection? - like modern arthropods Looks like trilobite
45
Exceptional biotas - examples and ecological strategies - Leanchoilia (slide 30)
Mid-gut glands replaced in calcium phosphate Digestive function Implies macrophagy and predation/scavenging
46
What is macrophagy?
Feeding on foods that are large relative to the size of the organism
47
Exceptional biotas - examples and ecological strategies - Anomalocaris (slide 31)
'Pineapple' shaped jawed arm with 'blades' | Kind of like shrimp
48
What are Pascichnia?
Grazers that create 2D features as they scour the surface of hard or soft substrate in order to obtain nutrients (scrape along surface leaving trail)
49
What does all of this information say about Cambrian marine communities in terms of ecological strategies?
Predation and filter feeding important eco strategy | Deposit feeding less important
50
What is a deposit feeder?
An aquatic animal that feeds on small specks of organic matter that have drifted and settled on the bottom of the seafloor
51
What evidence proves that predation and filter feeding was more important than deposit feeding in Cambrian marine communities?
Consistent with trace fossil evidence Hunting burrows Pascichnia rare in Cambrian settings

Intro to Earth Science (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions