Silurian And Devonian Periods

Front 1

Opercular gill:

Back 1

- plate of bone covers the gills
- swings out and swings in
- they open mouth and suck water in, then when they close mouth the operculum opens, and squeezes water out.
- This is an innvation for a uni directional flow of water, now the fish do not have to swim in order to breath.
- Allows for many innovations in feeding and living

Front 2

Ostracoderm:

Back 2

assortment of jawless fish representing several evolutionary lines that lived from the Ordovician through the Devonian.
- shell and skin
- used pharynx to draw water with food particles into their mouths and gills to filter the food.
- The muscular pharynx, was powerful because of currents by cilia. More food= larger body plans.
- Heavily armored in bony plates and scales
- Could not move paired extensions even if they had them
- No true vertebral chord, but rudimentary structures.
- Brain has three regions: forebrain, midbrain, hindbrain

Front 3

Pectoral fin:

Back 3

- high on the sides of the body, paired
- provide fine control over swimming
- bony fish
- used for a variety of task: getting food, courting, taking care of eggs and young, crawling on land
- articulate with the skeleton, moving the skins independently of the body

Front 4

Pectoral girdle:

Back 4

- Most vertebrates have this trait
- Anterior
- appendicular skeleton
- bony or cartilaginous structure in vertebrates that supports and is attached to the front limbs

Front 5

Pelvic fin:

Back 5

- pair of fins on underside of fish
- provide fin control
- helps stay streamlined, and for straight swimming.
- Attached to pelvic girdle
- Matches hind limbs in other vertbrates

Front 6

Pelvic girdle:

Back 6

- posterior in most vertebrates
- appendicular skeleton
- a bony or cartilaginous structure in vertebrates that supports and is attached to the hind limbs

Front 7

Placoderm:

Back 7

- class
- plate, skin. JAWED fish
- appeared in the Silurian and diversified in the Devonian and Carboniferous but left no direct descendants
- body’s covered in large, heavy plates of bone anteriorly and smaller scale posteriorly.
- Jaws
- Jaws had sharp cutting edges but no separate teeth
- Paired fins had internal skeletons and powerful muscles.

Front 8

Placoid scale:

Back 8

- as water moves across the body surface, it will creat a film that resists flow, wasting energy on movement
- placoid scales break up the film
- instead of being smooth the scales create microturbulance.
- Fish adapt this way, instead of bony plates.

Front 9

Primary plant cell wall:

Back 9

- polysaccharide rich: cellulose
- Responsible for many cell functions: Sturctural support, resist internal tugor pressure, control rate and direction of growth, card storage, cell-cell interactions
- Surrounds growing and dividing cells

Front 10

Rhizoids:

Back 10

- “roots”
- serve only to anchor bryophytes (plants) into the substrate and do not take up water or nutrients from it.
- Horizontal, modified plant steams that can penetrate the substrate and anchor the plant

Front 11

Secondary plant cell wall:

Back 11

- much thicker and stronger wall
- deposisted once the cell has ceased to grow
- lignin containing
- xylem fibrea, traceids walls

Front 12

Silurian period:

Back 12

- within the Palezoic era, within the Phanerzoic eon
- 443-416 Ma
- after Ordovician, before Devonian
- plants, algae start making mats in the transition zones
- trilobytes disappear, crustacea appear
- armored fishes
- Jawless fish: Agnatha, lamprey, hagfish
- Jaw evolves: Chondrichthyes
- Fins, placoid scales, teeth, body skeleton, swim bladder, opercular gill, tetrapod
- Plants: start to make transition to land: wax ,stomata, start evolving vascular tissue, lignin, mosses, liverwort

Front 13

Sporangia:

Back 13

- sporophyte generation begins after fertilization, divides by mitosis, producing multicellular diploid organism this body:
- develops the sporangia, which are capsules, where spores are produced by meiosis.

Front 14

Spores:

Back 14

- haploid
- germinates and divides by mitosis to produce a multicellular haploid gametophyte

Front 15

Sporophyte:

Back 15

- diploid generation
- produces spores by meiosis which are haploid.
- Embryo= new sporophyte generation, is contained within the gametophyte tissue

Front 16

Stomata:

Back 16

- pores in the cuticle covered surfaces
- open and close to regulate water loss, using 2 specialized guard cells
- main route of CO2 entry into leaves
- very important innovation in water conservation, and a reason plants were able to survive in terrestrial environments.

Front 17

Swim bladder:

Back 17

- hydrostatic organ that increases buoyancy.
- Derived from an ancestral air breathing air breathing lung that allowed early actinopterygians to gulp air, supplementing gill respiration in aquatic habitats where dissolved oxygen is low.
- Bag of air or gas, that changes volume depending on depth. Gas comes from blood, two sets of capillaries can add gases of remove gases.

Front 18

Tetrapod:

Back 18

- four foot
- monophyletic lineage
- most use four limbs for locomotion
- Many are amphibious, semi terrestrial or terrestrial, although turtles and porpoises returned to the sea secondarily.
- Adults generally use lungs to breath atmospheric oxygen

Front 19

Thallus:

Back 19

- a plant body not differentiated into stems, roots or leaves.
- No organization of tissues

Front 20

Tracheids:

Back 20

- a conducting cell of xylem
- usually elongated and tapered
- in vascular plants
- serve in transport of water and mineral salts
- structural support
- one of two part of the vascular system