Futuyma Kirkpatrick Evolution, 4e
Sinauer Associates
Troutt Visual Services
Evolution4e_Back_EndPaper_Fig_v1.ai Date 03-01-20174500 Mya
2.58 Mya23 Mya66 Mya4000 Mya3000 Mya2000 Mya419
Mya145
Mya201
Mya252
Mya299 Mya1000 Mya541(^485) Mya Mya
443
Mya
359
Mya
HolocenePleistocene
Pilocene
Miocene
Oligocene
Eocene
Paleocene
Tr
ias
sic
Ju
ra
ss
ic
Cr
et
ac
eo
us
Pa
leo
gen
e
Neog
ene
Quaterna
ry
Cen
ozo
ic
M
es
o
zo
ic
Pa
leo
zoic
Pr
ec
am
rb
nia
De
vo
nia
n
Carboni
ferous
Si
lu
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Ordo
vician
Cambrian
Permia
n
The Geological Time Scale
The Cenozoic era embraces seven epochs, Paleocene through Holocene. The older literature refers to the first five epochs (66–2.58
Mya) as the Tertiary period, and to the Pleistocene and Holocene (or Recent) (2.58 Mya–present) as the Quaternary period. Geol-
ogists now recognize, instead, the Paleogene (Paleocene through Oligocene, 66–23 Mya), Neogene (Miocene through Pliocene,
23–2.58 Mya), and Quaternary periods.
Era
Period
(abbreviation) Epoch
Millions of
years from
start to present Major events
Quaternary (Q) Holocene 0.012 Continents in modern positions; repeated glaciations and changes of
sea level; shifts of geographic distributions; extinctions of large mammals
and birds; evolution of Homo sapiens, spread out of Africa; rise
of agriculture and civilizations
Pleistocene 2.58
Neogene (Ng) Pliocene 5.33 Continents nearing modern positions; increasingly cool, dry climate;
Miocene 23.03 grasslands spread; modern families of mammals and birds; first apes
Paleogene (Pg) Oligocene 33.9 Radiation of mammals, birds, snakes, angiosperms, pollinating insects,
Eocene 56.0 bony fishes
Paleocene 66.0
Cretaceous (K) 145 Most continents separated; continued radiation of dinosaurs; increasing
diversity of angiosperms, mammals, birds; mass extinction at end of
period, including last ammonoids and nonavian dinosaurs
Jurassic (J) 201 Continents separating; diverse dinosaurs and other reptiles; first birds;
diverse mammals; gymnosperms dominant; evolution of angiosperms;
ammonoid radiation; Mesozoic marine revolution
Triassic (Tr) 252 Continents begin to separate; marine diversity increases; gymnosperms
become dominant; diversification of reptiles, including first dinosaurs;
transitional mammal-like forms; modern corals, teleost fishes
Permian (P) 299 Continents aggregated into Pangaea; glaciations; low sea level; increasingly
“advanced” fishes; diverse orders of insects; amphibians decline; reptiles,
including early mammal-like forms, diversify; major mass extinctions,
especially of marine life, at end of period
Carboniferous (C) 359 Gondwana and small northern continents form; extensive forests of early
vascular plants, especially lycopsids, sphenopsids, ferns; early orders of
winged insects; diverse amphibians; first reptiles
Devonian (D) 419 Diversification of bony fishes; trilobites diverse; origin of ammonoids,
tetrapods, insects, ferns, seed plants; mass extinction late in period
Silurian (S) 443 Diversification of agnathans; origin of jawed fishes (acanthodians, placo-
derms, Osteichthyes); earliest terrestrial vascular plants, arthropods
Ordovician (O) 485 Diversification of echinoderms, other invertebrate phyla, agnathan verte-
brates; mass extinction at end of period
Cambrian (–C) 541 Marine animals diversify; first appearance of most animal phyla and many
classes within relatively short interval; earliest agnathan vertebrates;
diverse algae
Ediacaran 635 Animal fossils (Ediacaran fauna); inferred lineages of sponges, cnidarians,
bilaterians
Cryogenian 720 Inferred (from DNA) animal lineages
(others) 2500 Earliest eukaryotes (ca. 1900–1700 Mya)
4000
Origin of life in remote past (first fossil evidence at ca. 3500 Mya); diver-
sification of prokaryotes (bacteria and archaea); photosynthesis gener-
ates oxygen, replacing oxygen-poor atmosphere; evolution of aerobic
respiration
Source: Geological names and dates are from the International Commission on Stratigraphy, http://www.stratigraphy.org
CENOZOIC
MESOZOIC
PALEOZOIC
PROTEROZOIC
ARCHEAN
Evolution4e_BackEndpapers2.indd 2 3/6/17 8:56 AM