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ERTH 2401 - Midterm 1 Exam Study Guide.
Dinosauria - answer✔Triceratops horridus, Passer domesticus (sparrow;
a representative derived bird), and all members of the
clade descended from their most recent common ancestor.
Dinosaurs - answer✔- are tetrapods
- are terrestrial
- have scales or feathers
- Femur head turned into socket
- Legs fully under body giving it a narrow gait
-have a bipedal, narrow stance with the femur head inserted into the acetabulum of the
sacrum.
- walk on their toes
Late Proterozoic - answer✔- 1000 Ma: 1st eukaryotes
- 750 Ma: first animal traces (protozoa)
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- 600 Ma: Oxygen accumulates forming Ozone layer
- 550 Ma: 1st fossil evidence for jellies, sponges, corals
Early Cambrian (541 - 509 Ma) - answer✔- modern phyla of animals begin to appear in the
fossilrecord.
- diversification of living things in the oceans: chordates, arthropods (e.g. trilobites,
crustaceans),echinoderms, molluscs,
Phylum Chordata - answer✔Possesses a notochord, a dorsal nerve cord, pharyngeal slits, and a
post-anal tail. Bilateral symmetry.
ex: Pikaia graciens.
Middle Cambrian (509 - 497 Ma) - answer✔~508 Ma - Burgess Shale fauna preserved. One of
the earliest fossil beds containing soft-bodied animal imprints
Late Ordovician - answer✔- life continued to diversify and
Cambrian forms went extinct. First chondrichthyan-like scales.
Silurian (444 - 419 Ma) - answer✔-430 Ma - First cartilaginous fishes in the fossil record. Sharks
diversify rapidly after this.
-420 Ma - First appearance of jawed & bony fish. More complex vascular plants, spider-like
arachnids and land scorpions appear on the land.
Early Devonian (419 - 393 Ma) - answer✔- Oceans dominated by Placodermi;
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sharks diversify; agnathans decline; first ammonites.
- Plants evolve leaves and roots; lycopod forests cover the land; terrestrial arthropods diverse
and common.
- Sea Level is high and vast coral reef systems develop
Late Devonian (383 - 359 Ma) - answer✔- Tetrapods can support their bodies and invade the
land.
- Late Devonian extinction starts ~ 375 Ma killing all placoderms and 99% of trilobites.
Carboniferous (359-323 Ma) - answer✔- Continents collided to form Pangaea.
- Labyrinthodontia and Lepospondyli amphibians dominant land vertebrates, some >2m.
- Arthropods very common.
- Vast forests
Late Carboniferous (Pennsylvanian)(323 - 299 Ma) - answer✔- some invertebrates achieve giant
size
- Amniote egg evolves allowing reptiles to rapidly evolve and
exploit the dry land.
- 320 Ma - Synapsids separate from sauropsids (reptiles).
Permian (299 - 251 Ma) - answer✔-Carboniferous rainforest collapse
3|Page
ALL RIGHTS RESERVED.
ERTH 2401 - Midterm 1 Exam Study Guide.
Dinosauria - answer✔Triceratops horridus, Passer domesticus (sparrow;
a representative derived bird), and all members of the
clade descended from their most recent common ancestor.
Dinosaurs - answer✔- are tetrapods
- are terrestrial
- have scales or feathers
- Femur head turned into socket
- Legs fully under body giving it a narrow gait
-have a bipedal, narrow stance with the femur head inserted into the acetabulum of the
sacrum.
- walk on their toes
Late Proterozoic - answer✔- 1000 Ma: 1st eukaryotes
- 750 Ma: first animal traces (protozoa)
1|Page
, ©BRAINBARTER EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
- 600 Ma: Oxygen accumulates forming Ozone layer
- 550 Ma: 1st fossil evidence for jellies, sponges, corals
Early Cambrian (541 - 509 Ma) - answer✔- modern phyla of animals begin to appear in the
fossilrecord.
- diversification of living things in the oceans: chordates, arthropods (e.g. trilobites,
crustaceans),echinoderms, molluscs,
Phylum Chordata - answer✔Possesses a notochord, a dorsal nerve cord, pharyngeal slits, and a
post-anal tail. Bilateral symmetry.
ex: Pikaia graciens.
Middle Cambrian (509 - 497 Ma) - answer✔~508 Ma - Burgess Shale fauna preserved. One of
the earliest fossil beds containing soft-bodied animal imprints
Late Ordovician - answer✔- life continued to diversify and
Cambrian forms went extinct. First chondrichthyan-like scales.
Silurian (444 - 419 Ma) - answer✔-430 Ma - First cartilaginous fishes in the fossil record. Sharks
diversify rapidly after this.
-420 Ma - First appearance of jawed & bony fish. More complex vascular plants, spider-like
arachnids and land scorpions appear on the land.
Early Devonian (419 - 393 Ma) - answer✔- Oceans dominated by Placodermi;
2|Page
, ©BRAINBARTER EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
sharks diversify; agnathans decline; first ammonites.
- Plants evolve leaves and roots; lycopod forests cover the land; terrestrial arthropods diverse
and common.
- Sea Level is high and vast coral reef systems develop
Late Devonian (383 - 359 Ma) - answer✔- Tetrapods can support their bodies and invade the
land.
- Late Devonian extinction starts ~ 375 Ma killing all placoderms and 99% of trilobites.
Carboniferous (359-323 Ma) - answer✔- Continents collided to form Pangaea.
- Labyrinthodontia and Lepospondyli amphibians dominant land vertebrates, some >2m.
- Arthropods very common.
- Vast forests
Late Carboniferous (Pennsylvanian)(323 - 299 Ma) - answer✔- some invertebrates achieve giant
size
- Amniote egg evolves allowing reptiles to rapidly evolve and
exploit the dry land.
- 320 Ma - Synapsids separate from sauropsids (reptiles).
Permian (299 - 251 Ma) - answer✔-Carboniferous rainforest collapse
3|Page
