Paleontology Exam 3 Review

Cambrian explosion

A time of trials

Burgess Shale

A fossil-rich deposit in Canadian Rocky Mountains

Exoskeleton

Protection against predators and dessication

Exoskeletons and Shells limit what?

Growth

Chitin

A type of carbohydrate found in exoskeleton

Arthropod

Jointed feet

All arthropods have

Jointed feet and limbs & an exoskeleton

Trilobite

Most arthropods during this time

Molt

Breaking free of an old skeleton and forming a new one

Body plan of an Arthropod

Head, Thorax, Abdomen

Open circulatory system

Fluid or blood (hemolymph) pumped through the body cavities around organs and not enclosed in blood vessels

Spiracles

The respiratory system that opens in the exoskeleton and allows gas from O2 and get rid of CO2

Hemolymph

Contains cells

Hemocytes

Immune cells

Molluska

Phylum consisting of soft organisms protected by a hard shell (snails, octopus, and squid)

Mantle

All mollusks have this

Calcium carbonate

Secretes and creates a shell

Bivalvia

Two valves or hinged shell organisms (examples: clams & mussels) that filter feed to get food

Examples of Ancient Mollusks

Brachiopods and Ammonites

Cephalopod

Head-foot

Gastropod

Stomach-foot

Cuttlefish are

Colorblind

Pseudomorphs

Ink and mucus decoys for cuttlefish as they escape

Pen

Used to stabilize the squid when swimming

Beak

Used to tear prey

Ink

A dark fluid produced as a defense mechanism

Hemocyanin

The transport of O2

Jet propulsion

How squid swim using retractor muscles

Copper

When it oxidizes, it turns blue, hence why squid have blue blood

Echinodermata

Spiny skin (examples: sea cucumber, sand dollar, sea urchins, sea stars)

How do Sea Stars/Starfish eat?

The stomach moves out of its body to digest the food alive

Endoskeletons

Made of ossicles (calcium carbonate)

Sieve plate

Used to draw water into their bodies through hydraulic pressure, helping them move their body

Spikes

Extensions of calcite, they are there for protection

Regeneration

There have to be stem cells present (they have to be differentiated)

Bilateral symmetry

When echinoderms reproduce, they undergo metamorphosis, which has this

Tetrapod

Four-footed organisms

Chordate

Notochord

Notochord

Tough rod on the backs of organisms that latches onto muscles (examples: sea squirts)

Vertebrae

Vertebral column

Notochord evolves into what?

Vertebrate (hard parts with an internal skeleton system)

Fish are the first to have what?

Vertebrate column

Agnatha

A class that describes the evolution of jaws

Advantages of Evolution of Jaws

Increased breathing (O2 flow), Eating becomes easier, and they become predators.

Ostracoderms

Extinct jawless fish

Acanthodii

The earliest class of jawed fishes that had a lot of fins

Placodermii

Plated fish

Dunkleosteus

A fish in the class Placodermi with a huge head

Devonian

Age of fishes

Devonian age

the golden age of fish, the development of reefs, and the spread of fern forests across land

Chondrichthyes

cartilaginous fish (were flexible due to collagen)

Osteichthyes

bony fish (internal skeletons)

Ray-finned fish

thin bones in fins

Lobe-finned fish

fatter bones and flesh in fins

Lungfish

an example of lobe-finned fish that eventually moved to land

Crossopterygians

lobe fin fish to early amphibians

Bryophytes

plants that moved onto land, also known as moss

Moss

lacks vascular tissue (limiting size)

Moving onto land

means preventing desiccation (waxy cuticles), new reproductive strategies, gravity, O2 out of the air

Plants and amphibians still need water for

Reproduction

Archaeopteris

link between ferns and gymnosperms

Amphibian

the first tetrapods on land

Arthropods

the first animals to move onto land, had the first insects fly and have exoskeletons

Plants or animals moved onto land first

Plants

Tiktaalik rosea

the missing link (½ fish ½ mammal)

Features of Tiktaalik rosea

fins, scales, primitive jaws (fish qualities), neck (amphibian quality), wrist formation, ribcage expanded (allowed for lungs to evolve)

Amphibian Respiration

have the beginning of lungs (they are big, hollow air sacs) & breathe through their skin

Salamander Respiration

keep gills, develop lungs

Ectotherm

gets body temperature from the environment (very slow metabolism)

Endotherm

regulates body temperature (helps metabolism)

Carboniferous period

age of swamps and bugs

Key events of Carboniferous

diversification of insects/arachnids & highest oxygen levels (35%), decline of trilobites, and evolution of first reptiles

Megacephalus

10-foot amphibians

Internal fertilization

utilized through cloaca or double penis system

Coal

Compressed plant matter

Hylonomus

the earliest reptile

Cloaca

reproduction and waste

Scales

skin on reptiles

Desiccation

the removal of moisture from something

Amniotic egg

leathery shell filled with fluid inside that allowed tetrapods to spread out

Basking

increases body temperature, which increases metabolic rate

First flowers bloomed in what period

The Cretaceous

Ammonia

nitrogenous waste products

Urea

less toxic than ammonia

Uric acid

blood filtered by the kidneys is excreted, which is converted to this (birds)

Pelycosaur

fin-back reptiles (not a dinosaur, instead a lizard) that eventually evolved into Therapsids

Dimetrodon

a big plate for temperature regulation

End of Permian

Mass extinction and Pangaea begins breaking up

Mesozoic Era

The Age of Dinosaurs

Plants evolved into what in the Triassic

cycads and gymnosperms

Amphibians evolved in what period

Triassic

Gymnosperms

naked seeds that reproduce from flying sperm (pollen)

Angiosperm

vessel seeds

Eoraptor

one of the first dinosaurs

Therapods

coclophysis or terrors on two feet