2. Precambrian, period of time extending from about 4.6 billion years ago to the
beginning of the Cambrian Period, 541 million years ago. The
Precambrian encompasses the Archean and Proterozoic eons, which are formal
geologic intervals that lasted from 4 billion to about 541 million years ago, and
the Hadean Eon, which is an informal interval spanning from 4.6 billion to 4 billion
years ago. The Precambrian represents more than 80 percent of the total geologic
record.
Cambrian Period, earliest time division of the Paleozoic Era, extending from 541
million to 485.4 million years ago.
Geologic Time
Ordovician- geologic period 485. 4 million years ago- 443 million years ago.
4. INVERTEBRATE: Porifera
Evolutionary Time Frame
Among the oldest known fossils began in
late Precambrian
developed from first multi-cellular
organism
no coelom, organs, or skeleton
no urinary, cardiovascular, respiratory
or nervous system
Reproduce sexually or asexually
Hermaphrodites
carnivores
Characteristics
6. INVERTEBRATE: Cnidaria
Evolutionary Time Frame
Cnidaria first appeared during the Pre-Cambrian
era
few fossils in Cambrian period, but identifiable
corals began evolutionary radiation in Early
Ordovician Period
wiped out at end of Permian Period
mass extinction event in which 95% of all marine
invertebrate species became extinct
scleractinian corals appeared in the middle of the
Triassic (15 million years later)
became dominant hermatypic (reef-building)
organisms in shallow tropical marine habitats
do not have a cardiovascular system
Simplest organisms at tissue level
Cnidarias have one oral opening
Alternate between asexual and sexual
move freely in water by passive drifting
and contractions of its bell-shaped body
Cnidaria are carnivores
Characteristics
8. INVERTEBRATE: Platyhelminthes
Evolutionary Time Frame
Origin of bilaterians, Precambrian period before
Cambrian explosion
early origin of coelom hypothesized by trace
fossils left in Precambrian sediments
“flat worm”
Most Reproduce asexually, while some do
reproduce sexually
the parent constricts in the middle each
half regenerates its missing end
cross-fertilization between individuals
Glide along a film of mucus
absorb nutrients across the body surface
fluid filled spaces aid in transport
Characteristics ectoderm
mesoderm
endoderm
10. INVERTEBRATE: Nematoda
Evolutionary Time Frame
Found as early as the Carboniferous period
fossils of nematodes were found in amber, these
dated back to the Cenozoic era
Nema - “thread”
Contain internal body cavity-pseudoderm
Reproduce sexually with internal
fertilization
Muscles are longitudinal and contract
producing a thrashing motion
Have mouth opening into pharynx (throat)
No cardiovascular system
Characteristics
12. INVERTEBRATE: Mollusca
Evolutionary Time Frame
Lived in freshwater streams as early as 400 million
years ago
developed the ability to be able to live in most
aquatic environments-300 million years ago
mollusks are soft bodied- protected by a hard shell
made of calcium carbonate
Three main parts:
Muscular foot (for movement)
visceral mass (containing the internal organs)
mantle (fold of tissue, drapes over visceral mass,
secretes shell)
Excretory organs called nephridia
Muscular foot
Feed by a strap like rasping organ called the radula to
scrap food
Open circulatory system
Gills housed in mantle cavity
Clams and chitons have no nervous system
squid and octopus have most sophisticated nervous
system of all vertebrates
Characteristics
14. INVERTEBRATE: Annelida
Evolutionary Time Frame
Originated in Precambrian
Annelids means “little rings”
Segmented worms
Cross-fertilization
some reproduce asexually by fragmentation
Closed cardiovascular system
The respiratory organ is the skin
Characteristics
16. INVERTEBRATE: Arthropoda
Evolutionary Time Frame
Soft-bodied relatives began during the Vendian
rapid evolution in Cambrian Period
Trilobites (the dominant marine group) began in
the Paleozoic
arachnids moved onto land during Devonian 385
million years ago
oldest insect fossil from the Devonian Period 400
million years ago
arthropod means “jointed feet”
exoskeleton
-made of tough compounds, chitin and protein
Paired reproductive organs (ovaries and
testes)
Movement of appendages is controlled
primarily by a complex muscular system
Open circulatory system
Organs specialized for gas exchange
Well developed sensory organs
Characteristics
18. INVERTEBRATE: Echinodermata
Evolutionary Time Frame
Fossils are not pentameral
oldest known Venedian fossil is Arkarua
soft bodied with unmineralized plates
modern Echinodermata (with mineralized skeleton)
entered the fossil record in early Cambrian
Asterozoans date back to Ordivician
crineids and blastoids are the later Paleozoic
became extinct at the end of the Permian Period
echin “spiny” derma “skin”
External fertilization
Tube feet
hydraulic water vascular system
Characteristics
20. postanal
tail notochord
hollow dorsal
nerve cord
pharyngeal
pouches
becomes brain &
spinal cord
becomes
vertebrae
becomes gills or
Eustachian tube
becomes tail or
tailbone
vertebrate embryo
CHORDATA
Vertebrates
Vertebrates have the ability to regenerate ATP
by cellular respiration
all have a closed circulatory system with
ventral, chambered heart
blood is oxygenated as it passes through
capillaries in gills or lungs
Characteristics
21. Chondrichthyes
sharks, rays
Have cartilaginous skeletons
Two kidneys
Sexually dimorphic
Jaw and muscles push food down
esophagus
Powerful swimming muscles in caudal
(tail) fin
Two chambered heart with one atrium
and one vesicle
Gills pull oxygen from the water
Central nervous system with a brain
and spinal cord
Characteristics
Evolutionary Time Frame
Appeared 450 million years ago
cartilaginous skeleton is a derived
characteristic.
22. Osteichthyes
ray-finned, lobe-finned, lungfish
Bony fishes
Two small kidneys work to excrete
wastes
Oviparous
Glands in skin secrete mucus giving
sliminess, reduces drag during
swimming
Three chambered heart
water is drawn in through pharynx and
out between gills by movement of
operculum and contraction of muscles
surrounding gill chambers
Two pairs of cranial nerves
Characteristics
Evolutionary Time Frame
500 million years ago during the Cambrian
period
23. Amphibia
salamanders, frogs, caecilians
Amphibian means “two lives”
Coelom
External fertilization
Three chambered heart
double circulation
Rely on moist skin
Characteristics
Evolutionary Time Frame
Earliest amphibia found in early Devonian period-
363 millions years ago
modern amphibia didn’t appear until Mesozoic era-
248 million years ago
24. Reptilia
snakes, lizards, crocodiles, turtles, birds
Have scales containing the protein keratin
Lay shelled amniotic eggs on land
Agile and fast-moving
Closed circulatory system
three chambered heart
Cannot obtain oxygen through their skin
which is keratinized and dry
Advanced nervous system compared to
amphibians
Characteristics
Evolutionary Time Frame
Reptilia were more numerous and diverse during the
Mesozoic era
go as far back as the late Carboniferous Period -350
million years ago
the oldest fossils were found in Kansas in the late
Carboniferous period-300 million years ago
ancestors are the Devonian amphibians
25. Mammalia
Possession of mammary glands
Four types of tissue
Kidney
separate sexes
Differentiation of teeth for different foods
four chambered heart
Diaphragm ventilates lungs
Larger brains
Characteristics
Evolutionary Time Frame
Evolved from reptilian stock during Mesozoic era,
even before birds did-180 million years ago
