Open Earth Systems: An
Earth Science Course
For Maryland Teacher
Professional Development
EARTH HISTORY AND THE FOSSIL RECORD
DAY 1 - Weds. July 8
AM Instruction: Solar System Origin
Activity 1: Period of planetary orbits
Activity 2: Planets on your birthday
Instruction: Early Earth & Habitability
-lunchtimePM Instruction: Major Events in Earth History
Activity 3: Exploring Geologic Time with TS-Creator
Instruction: Concepts in Radioisotope-dating
Activity 4: Simulating Radioactive Decay
DAY 2 - Thurs. July 9
AM Instruction: Climates of the Past
Activity 5: JHU Soil Profile
Instruction: Fossil Record of Life
-lunchtimePM Instruction: Conversation with Steven Stanley
Activity 6: Fossil Identification
LINDA HINNOV, Instructor
OUTLINE
Origin of Moon
Late Heavy Bombardment
Plate Tectonics
Great Oxidation Event
Eukaryotes
Snowball Earths
Macrofossils
Cambrian Explosion
Plants on Land
Tetrapods
Dinosaurs
Mammals
Introduction
Earth history highlights
J. Valley, Wisconsin
Geologic TIme Scale
The Geologic Time Scale
Chaotian/
Hadean
Origin of Moon
Canup, 2013
Late Heavy Bombardment
Late heavy bombardment
Ocean vaporizing event
Earth craters (filled boxes)
Chiron (future)
From 4.0 to 3.8 Ga,
the Late Heavy
Bombardment
occurred, which
would have
vaporized the
ocean and
exterminated any
pre-existing life;
accordingly, we
name the upper
Neohadean period
Promethean.
Moon craters (open boxes)
Kasting and Catling, 2003
Apex Chert Fossils (Bacteria)
BUT DEBUNKED
IN 2011 AS
HEMATITE-FILLED
FRACTURES
Schopf Locality
3 of 11
discoveries
Schopf, 1993
Plate Tectonics
(maybe early as Mesoarchaen)
http://www.lithosphere.info/
“Faint young sun paradox”
“Faint young sun paradox”
One solution:
Kasting, 1987
Another solutions:
Earth was closer to Sun
Sun wasn’t as faint as assumed
Great Oxidation Event
• Stromatolites
– 3.5 Ga
– Suggest photosynthesis
• Biomarkers for
cyanobacteria
– 2.7 Ga
– free
maybe
later
(1.7atmosphere
Ga)
Release of
oxygen
into the
GOE
Great Oxidation Event
Great Oxidation Event
Supercontinent cycles
With the assembly
of continents, there
is increase in
erosion, and more
nutrients fluxing to
the oceans,
leading to blooms
of photosynthesizing
organisms (cyanobacteria, algae),
increasing O2.
Campell and Allen, 2008
First eukaryotes
Single-celled eukaryote acritarchs,
appear at 2.1 Ga. Acritarchs are
the most common fossils of the late
Proterozoic. May be resting stages,
or cysts, of dinoflagellates, which
are one of the most prominent
groups of planktonic algae today.
The large size of many acritarchs
(60 to 200 microns or larger)
indicates they were eukaryotes.
Multi-cellular vendotaenid algae from
Namibia. Image from D. Erwin, NMNH.
http://paleobiology.si.edu/geotime/main/htmlversion/evidence/pro_01.html
The boring billion
Secular variation in marine d¹³C from 2.5 Ga to present indicate
unusual stability of the Earth’s carbon cycle.
Note extreme Neoproterozoic isotopic variability and correlation
of negative excursions with glaciations.
boring billion
glaciation
http://www.geol.umd.edu/~kaufman/iceages.html
Snowball Earths
boring billion
Hoffman and Schrag, 2000
Macrofossils
Ediacaran biota
mya
Elevated atmospheric oxygen
The Neoproterozoic Oxygenation Event (NOE)
GOE
NOE
Wiese and Reitner (2011)
Cambrian (and Ordovician) explosions of marine life
Cambrian explosion – shelly faunas
Worm tubes?
conodontomorph
Tommotian fauna –
oldest known diverse skeletonized fauna
Primitive mollusk
Sponge
spicule
C-E: unknown forms
http://www.palaeos.com/
Millimeter-sized shelly fossils from
China, Siberia (actually end-Vendian)
Ordovician explosion – diversification
ALL SPECIMENS ONLY A FEW MM!
A-Nautiloid (mollusk)
B-Spiny trilobite
C-Smooth trilobite
D-Gastropod (mollusk)
E, F-Brachiopods
G-Bivalve (mollusk)
H-Bryozoan colony
I-Tabulate coral colony
J-Stromatoporoid colony
K-Rugose coral (tetracoral)
Stanley (2005)
Silurian land invasions
Vascular plants – innovations to capture water and nutrients
Cross section of
stem showing
vascular structure
• Invaded land in the Late Silurian by
developing rigid stem and root system
• Vascular plants
– Tubes deliver water and nutrients
– Rhynia
– swampy habitat
Stanley (2005)
Animals - millipedes, wingless insects, and scorpions
Fossil scorpion (Palæophoneus nuncius) found
in the Silurian rocks of the Island of Gotland of
Sweden.
Devonian greening of continents; fish radiation
Seed and spore plants, gymnosperms
• Gymnosperms
–Upland habitat
–Cordaites
• Lycopods (spore plants)
–Swamp habitat
–Lepidodendron (up to 30 m tall!)
Fish radiation
• Seed ferns
–Abundant
–Small bushy plants
–Large and treelike
– Glossopteris (‘tongue leaf’)
ANCESTORS
OF ALL
TERRESTRIAL
VERTEBRATES!
Stanley (2005)
Carboniferous tetrapods
Amphibians and reptiles
Dimetrodon
Eryops
• Amphibians
-aquatic, semi-aquatic
-first onto land
–Eryops
• Reptiles
–amniote egg
–Protect embryo
–Not aquatic
–Ectothermic
–Dimetrodon
Dimetrodon
predator of
Eryops?
Winged insects
•Winged insects
–Dragonflies
–Mayflies
By Late Carboniferous
foldable wings had evolved.
Stanley (2005)
Permian life
Divergence of reptiles
[Dinosaurs-Triassic]
Thecodonts
Archosaurs
[Mammals-Triassic]
Therapsids
Pelycosaurs
(Most dominant)
Diapsids
Synapsids
Anapsids
increase in jaw musculature
In the Late Carboniferous two major clades of reptiles diverged from the original Anapsid
reptiles (A), the Synapsids (B; ‘fused arch'-one temporal fenestra) and the Diapsids (C;
‘twin-arched’-two temporal fenestrae). Both groups are extremely important: the synapsids
led to the evolution of mammals; the diapsids gave rise to the dinosaurs.
http://www.ucmp.berkeley.edu/diapsids/
http://faculty.plattsburgh.edu/thomas.wolosz/pre-dino.htm
Triassic tetrapod evolution
Dinosaurs
Bird-hipped
Note: birds evolved
from reptile-hipped
Reptile-hipped
Pelvic structure
different
Dinosauromorphs
Lagosuchus
mammal
Stanley 2005
Mammals
First mammal was Megazostrodon, a small shrew-like insectivore
from the Late Triassic. It had cheek teeth differentiated into
premolars (which are replaced once) and molars (which erupt as
permanent teeth). Absence of molar teeth from the “milk set” is
indication that Megazostrodon (like recent mammals) provided
milk for their young.
Jurassic dinosaurs; marine primary producers
Dinosaurs
By Late Jurassic, bird-hipped herbivores, and lizard-hipped carnivores and herbivores
were diverse and abundant. LARGEST group were sauropods, lizard-hipped herbivores.
Late Jurassic sauropods
Camarasaurus
Diplodicus
Stanley 2005
Stegosaurus
Allosaurus
Pterosaurs
Marine phytoplankton
Calcareous nannoplankton
Dinoflagellates
Diatoms
Cretaceous dinosaurs; rise of angiosperms
Pterosaurs
Social Maiasaurs
Corythosaurus
Tyrannosaur
Chasmosaurs
Kritosuarus
Monoclonius
Edmontonia
Angiosperms
Pollen
Leaves
Stanley 2005
• Greek word “angion” meaning container
• monocts (25%; seeds have 1 cotyledon;
orchids, lilies, grasses, palms); dicots (2
cotyledons; 75%; oaks, maples, roses, peas)
• double fertilization
• flowers attract pollenators; produce fruits
• oldest ~125 Ma (but could be >200 Ma)
Double fertilization explained here:
https://www.youtube.com/watch?v=dgFY7WUTASQ
Cenozoic mammal radiation; grass evolution
Stanley (2005)
Mass Extinctions
1. Short event (~1 Myrs)
2. Disappearance of > 60%
Glaciation
of species (> 10% families)
Bolide
impact 3. Global in scale
End-Ordovician
Volcanism
(Siberian Traps)
Permian/Triassic
80-96% marine loss
Glaciation?
Devonian
Cretaceous/Tertiary
60-75% marine loss
Volcanism
(CAMP*)
End-Triassic
Shaded band indicates the
normal range of extinction
rates, known as "background
extinction." The peaks show
the "Big Five" mass
extinction events at the end
Ordovician, Late Devonian,
Permian/Triassic (P/Tr)
boundary, the end Triassic,
and Cretaceous/Tertiary (K/T)
boundary.
* CAMP=Central Atlantic Magmatic Province)
http://www.pbs.org/wgbh/evolution/library/03/2/l_032_01.html
Phanerozoic History Summary