An Explosion of Life Flashcards
1
Q
earth 2 byr ago …
A
land and ocean looked barren
2
Q
ocean looked barren 2 byr ago
A
- no fish, lobster, reefs
- prokaryotes diverse
- photosynthetic prokaryotes
2
Q
land looked barren 2 byr ago
A
- no plants
- no animals
- prokaryotes present
- eukaryotes rare and single celled
3
Q
the oldest animal fossils
A
sponges
4
Q
Precambrian: 650 mya
A
fossils sponges
5
Q
Precambrian: 635 mya
A
evidence of cholesterol-like molecules that today are only made by sponges
6
Q
Precambrian: 565-544 mya
A
a diversity of multicellular organisms grouped together as the Ediacaran fauna
7
Q
metazoans present 565 mya include
A
- jellyfish
- comb jellies
- sponges
8
Q
features of Ediacaran Fauna
A
- asymmetrical or radial symmetry
- small
- no hard parts
- some fossils with no clear. modern analogues
8
Q
trace fossils
A
fossil trails, burrows, footprints, or any other trace of an organism rather than of the organism itself
8
Q
summary of the Ediacaran Fauna
A
- limited morphological diversity
- limited ecological diversity
- bilateral symmetry rare
- mostly soft
9
Q
Ediacaran Fauna dominated by:
A
- sponges
- comb jellies
- jellyfish
- other soft-bodied things
10
Q
Ediacaran fauna mode of living
A
- sessile filter feeders
- predators that floated high in the water column
11
Q
the Cambrian Explosion
A
- nearly all of the remaining phyla of animals appear suddenly
- increased in structural diversity and mode of living
12
Q
Cambrian Explosion body parts
A
- segmentation
- limbs
- calcarious shells
- antennae
- notochords
- external skeletons
