Late Paleozoic Flashcards
What is categorized in the Carboniferous?
Mississippian and Pennsylvanian
When does the Paleozoic end?
At the end of the PERMIAN
What was the oldest fish on Earth? What is unique about them?
AMPHIOXUS
Are jawless fish, incapable of biting, not great at being predators
Came after Pikaia
What happened at the start of the Devonian regarding fish types?
New types of fish emerge with the very first JAWS
How did jaws develop?
Jaws developed from gill arches which consist of small bones that support each gill
These arches fused and hinged to form the jawbone
What’s the difference between SHARKS and the JAWLESS FISH?
Sharks have 3 LESS gill arches and 2 LESS gills compared to the jawless fish
Used the gill arches and gills to form the jaw
Do all chordates (animals with spinal chord) have gills and gill arches?
YES
During the EMBRYONIC stage, dissapears during development
How did humans use their gills and gill arches?
Humans have gill arches that are repurposed to our ear bones, jaw, and neck
Gill arches fuse together, sealing the gills
LEAVES BEHIND REMANENT OF A GILL AS AN EAR PIT
What are the two main types of JAWED FISH?
BONY FISH (Fish)
CARTILAGINOUS FISH (Sharks, Stingrays)
What are cartilaginous fish?
Have a skeleton that consists of cartilage, rather than bone
Ex. SHARKS
What is so unique about sharks?
FIRST animals to have discrete mineralized teeth that could be preserved, no actual bones to preserve besides teeth
What are bony fish? Some innovations?
Use of bones instead of cartilage
Having a SWIM BLADDER filled with gas and helps maintain buoyancy in the ocean
Who were the first animals to have ribs?
Bony fish were the FIRST animals to have ribs
What is the innovation of swim bladders from fish/
LUNGS for breathing air, lunges developed by adding more surface area and blood vessels to the swim bladder
What are lungfish?
Was probably the first to step out onto land
CAPABLE OF USING GILLS OR LUNGS
What are the two primary types of BONE FISH?
(LUNG FISH) Lobe-finned fish = fleshy lobes for fins
(TYPICAL FISH) Ray-finned fish = fins with bony rays
Where did 4-legged animals come from?
FISH SIMILAR TO THE LUNGFISH WITH LOBE-LIKE FINS
Modifying a lobe-finned fish into an amphibian requires very little change since their anatomy is very similar
What needs to be done for fins on a lobe-finned fish to become amphibian arms?
NOTHING
All the bones necessary for an amphibian arm are present within the fin of the lobe fish
ONLY SPECIALIZATION OF THE FIN BONES IS NECESSARY
What is the final step to create the earliest land animals aka amphibians?
REDUCTION OF FINGER BONES
ALL modern amphibians have 5 or fewer digits
What are the evolutionary traits that fish evolved into to create amphibians?
- Gills and gill arches fuse to create the jaw, ear bones, and neck
- Creation of ribs, first animals to have ribs
- The creation of the swim bladder that later became the lungs
- Creation of amphibian arms from the fin of the lobe-finned fish
- The reduction of finger bones to 5 or less digits
What are the likely origins of early plant life?
ALGAE
Algae make up a major coastal component today and could easily leap to land
What was the major problem for sea plants moving to land and surviving? How did they solve this?
THE AVAILABILITY OF WATER
Plants had solved this problem with ROOTS
How did plants use their roots to survive?
Plants can transport water up through their roots and stem
THEY HAVE A VASCULAR SYSTEM BECAUSE OF THE ROOTS
Takes water from the ground and sends it up
What are the many traits that sea plants acquire to survive on land?
Roots to transport water
Waxy coating to prevent water from entering or leaving the plant (prevents them drying out)
Creation of stomata, little holes in the leaf, that can keep or release gas or water (hot sunny, holes close to preserve water)
Where in the plant does photosynthesis occur?
Conduct all photosynthetic transactions through the stomata due to their waxy coating
Stomata take in carbon dioxide and release oxygen
What did all of the earliest land plants have despite their very simple genetic makeup?
What was their genetic makeup?
THEY ALL POSSESSED A VASCULAR SYSTEM
These early plants had a narrow stem, small leaves, and a few rootlets
What happened by the end of the Devonian regarding land plant life?
LARGE TREES HAD EMERGED AND SPREAD THROUGHOUT THE WORLD
These trees formed the world’s first forests
Ex. Archaeopteris
What happened as the Devonian period comes to a close?
SECOND MASS EXTINCTION EVENT
What is the late Devonian extinction associated with? (Rock layers)
Marine rock layers that are carbon-rich like coal
How can rocks in the ocean become carbon-rich?
Stagnant, low-oxygen water prevents decay
How did trees help create carbon-rich layers?
As trees washed away into the ocean, they would start to decay from organisms eating them, oxygen is consumed rendering the ocean anoxic
What are anoxic conditions (no oxygen)?
Massive amounts of organic carbon could be buried
The preserved carbon reflects low-oxygen water
What can exterminate shallow marine ecosystems?
Transgression can bring up anoxic water from deep parts of the ocean to shallow water environments
LATE DEVONIAN = 2 MASSIVE TRANSGRESSIONS (WATER RISE)
What is one sign that a transgression has occurred that killed off shallow marine life?
Black carbon-rich mudstone is shown with HORIZONTAL BEDDING, meaning that bioturbation stopped
Animals go extinct, they can not have bioturbation
What is the relationship between bioturbation and the amount of oxygen?
AS OXYGEN DECLINES, BIOTURBATION DECLINES AS WELL
What caused the Late Devonian Mass Extinction event???
The transgression of anoxic water conditions devastated reefs
When do reefs recover?
REEFS DO NOT RECOVER UNTIL THE PERMIAN PERIOD
