ERTH305 Midterm 1

What are fossils, and where does the name come from?(3)

• Fossils are vestiges of ancient life

• Comes from latin for “to be dug out from the Earth”

• According to early definition, minerals were also considered fossils

What is the most basic classification for vestiges of ancient life forms, and where do they differ?(2)

• Fossils: older than 11700 years

• Subfossils: younger than 11700 years; not all younger vestiges of life are considered fossils

What are the three classifications of fossils according to their nature?(3)

• Body Fossils: preserve a part of the organism, or are structures that reflect a part of the organism; hard and soft body parts

• Trace Fossils: preserve a certain activity of an organism

• Chemical Fossils: only small components of the original organism are preserved(DNA, fossil fuels etc)

Body or Trace fossil?

Body; Stony coral

Body or Trace fossil?

Body; Cephalopod shells

Body or Trace fossil?

Body; Trilobite

Body or Trace fossil?

Body; Cephalopod

Body or Trace fossil?

Body; Mollusc

Body or Trace fossil?

Body; Insect

Body or Trace fossil?

Trace; movement of an unknown organism

Body or Trace fossil?

Trace; vertical galleries dug by an unknown organism

Body or Trace fossil?

Trace; moving traces left by a belemnite on the sea floor

Body or Trace fossil?

Trace; moving traces left by a polychaete worm

Body or Trace fossil?

Both; moving traces and the organism that left them, a horseshoe crab

What is the process of fossilization?(2)

• A highly destructive process that transforms a dead organism into a fossil

• Not all living organisms, or organisms that once lived on Earth, will be fossilized

What are the conditions of fossilization?(2)

• The organism must be buried rapidly(eg landslide), or there is a high rate of sedimentation within the basin

• Anoxic conditions at the bottom of the basic increases the fossilization potential

Explain Petrification, and if it is casual or high-quality fossilization(3)

• Casual

• Occurs in the case of fossils that present a porous internal structure

• Both lithification and permineralization

Explain Lithification, and if it is casual or high-quality fossilization(3)

• Casual

• Occurs in the case of fossils that present a porous internal structure

• The transformation of the hard body parts into stony material

Explain Permineralization, and if it is casual or high-quality fossilization(3)

• Casual

• Occurs in the case of fossils that present a porous internal structure

• Pore filling with different minerals

Explain Recrystallization, and if it is casual or high-quality fossilization(3)

• Casual

• Transformation of one mineral of the hard body parts into another

• Most frequent is calcification, where aragonite transforms into calcite

Explain Carbonization, and if it is casual or high-quality fossilization(3)

• Casual

• Life forms on Earth are dominated by CHON SP

• Elements are expelled during burial and transformed into carbon

Explain Moldic Fossilization, and if it is casual or high-quality fossilization(4)

• Casual

• Complete or partial removal or hard body parts

• Forms an empty space inside sedimentary rocks, leaving lithified sediment

• Driving process is dissolution

Explain Replacement, and if it is casual or high-quality fossilization(3)

• Casual

• Empty space from moldic fossilization is filled with a newly precipitated mineral

• One example is pyritization

Explain Impression, and if it is casual or high-quality fossilization(2)

• Casual

• Fossils that are produced by the weight of a dead fossil imprinted on a soft sediment

Explain Fossilization in Amber, and if it is casual or high-quality fossilization(2)

• High-quality

• Amber is a natural resin with high viscosity

Explain Fossilization in Tar Pits, and if it is casual or high-quality fossilization(2)

• High-quality

• Happens in tar swamps, where hydrocarbons from Earth’s interior reach the surface

Explain Congealment, and if it is casual or high-quality fossilization

• Trick question, do not need to know. If it is an answer, it is incorrect

Explain Desiccation, and if it is casual or high-quality fossilization

• Trick question, do not need to know. If it is an answer, it is incorrect

What is a Fossil Lagerstätten?(3)

• “Fossil Ores”

• Fossils where soft body parts are preserved

• Approximately 100 known, including the Burgess Shale and Chengjiang Fauna

What kind of fossilization is this?

Permineralization

What kind of fossilization is this?

Permineralization

What kind of fossilization is this?

Petrification; Lithification, and Permineralization

What kind of fossilization is this?

Petrification; Lithification, and Permineralization

What kind of fossilization is this?

Recrystallization

What kind of fossilization is this?

Carbonization

What kind of fossilization is this?

Moldic Fossilization

What kind of fossilization is this?

Moldic Fossilization

What kind of fossilization is this?

Replacement (pyritization)

What kind of fossilization is this?

Impressions

What kind of fossilization is this?

Fossilization in amber

What kind of fossilization is this?

Fossilization in tar pits

What kind of fossilization is this?

Fossil Lagerstätten - Burgess Shale

What kind of fossilization is this?

Fossil Lagerstätten - Chengjiang Fauna

What is the difference between relative and absolute time?(2)

• Relative: no numbers

• Absolute: numbers

What are Steno’s Principles of Stratigraphy?(4/5)

1. Principle of Layer Superposition

2. Principle of Layer Successive Formation(fake)

3. Principle of Original Layer Horizontality(actually 2)

4. Principle of Lateral Layer Continuity(actually 3)

5. Principle of Cross-Cutting Relationships(actually 4)

What is the principle of layer superposition?

• In a sequence of undisturbed layers, the oldest layer is at the bottom

What is the principle of successive layer formation?

• At a layer’s formation time, only fluid existed above it

What is the principle of original layer horizontality?(2)

• Layers should all have been horizontal, and if they are not, they have been disturbed

• However, layers at the sea floor may be irregular, because the sea floor itself is not flat

What is the principle of lateral layer continuity?

• Strata extend in all directions until they terminate by thinning at the margins of the basin

What is the principle of cross-cutting relationships?

Any feature, such as a fault, fracture or intrusion, is younger than the rock that it disturbs.

What are the two steps of calculating geological time?(2)

1. Development of the relative geological time scale

2. Development of a method to calculate the age of a mineral formation

Explain the development of the geological time scale(3)

• Started in 1665, is still ongoing

• Involves the arrangement of layers of rocks into order by age

• Was first done for sedimentary, then expanded to metamorphic and igneous

When did people start calculating the age of mineral formations?(2)

• Started in 1912, still ongoing

• First consistent results produced in 1970

Main points of the hadean eon(2)

• No rock record

• Earth was mostly molten

Main points of archean eon(2)

• Start: Oldest rocks

• End: Formation of convection currents, modern plate tectonics

Main points of proterozoic eon(2)

• First animals

• Start of modern plate tectonics

Main points of phanerozoic eon

• Lots of rocks with large fossils

How long was each eon?(4)

• Hadean: ~600 million years

• Archean: ~1.5 billion years

• Proterozoic: ~ 2 billion years

• Phanerozoic: ~500 million years

Paleozoic/Mesozoic boundary(3)

• Ocean conveyor collapse

• Great dying

• Raised temperatures

Mesozoic/Cenozoic boundary

• Asteroid that killed the dinosaurs

What are the 4 major events on Earth?(4)

• Asteroid Bombardment: Hadean → Archean

• Atmosphere Character Shift: Archean → Proterozoic

• Extensive Glaciations: Neoproterozoic

• Ocean Conveyor Collapse: Paleozoic → Mesozoic

What was the hadean asteroid bombardment?

During the Hadean eon, multiple asteroids struck the Earth, causing the surface to never solidify, and oceans to vaporize

What was the atmosphere character shift?(2)

• Cyanobacteria evolved to produce oxygen as a byproduct

• Volcanic outgassing transitioned to a more oxidizing state

What were the extensive glaciations?(3)

• Snowball Earth

• Due to dimmer Sun

• Due to dramatic drop in atmospheric carbon dioxide

What was the ocean conveyor collapse?(3)

• Wiped out 90% of marine life, 70% of terrestrial life

• The great dying

• Volcanic eruptions pumped greenhouse gases carbon dioxide and sulfur dioxide into the atmosphere

What is paleontology?(2)

• A subdiscipline of geology that studies the vestiges of ancient life forms

• Close connection with biology, distant connection with genetics

What is paleobiology?

• Basically a fake science that does not offer enough data integration with geology as paleontology does.

What are the 6 subdivisions of paleontology?(6)

• Micropaleontology: the study of microscopical fossils

• Paleoalgology: the study of fossil algae

• Paleobotany: the study of fossil plants

• Palynology: the study of fossilized reproduction structures of higher plants

• Invertebrate paleontology: the study of invertebrate animals

• Vertebrate paleontology: the study of animals with an axial skeleton

What are the 4 related sciences of paleontology?(4)

• Paleoecology

• Paleobiogeography

• Biostratigraphy

• Evolutionary paleontology

Who wrote the initial Linnaean hierarchy, and what was it called?(4)

• Carl Linnaeus

• “Systema Naturae”

• Current edition is 10th edition

• It did not become important or used until after Linnaeus’ death

What is the original Linnaean hierarchy?(5)

• Kingdom

  • Class

    • Order

      • Genus

        • Species

What is the improved Linnaean hierarchy?(7)

• Kingdom

  • Phylum

    • Class

      • Order

        • Family

          • Genus

            • Species

What is the modern Linnaean hierarchy(8)

• Kingdom

  • Phylum → Subphylum

    • Superclass → Class → Subclass → Infraclass

      • Superorder → Order → Suborder → Infraorder

        • Superfamily → Family → Subfamily

          • Tribe → Subtribe

            • Genus → Subgenus

              • Species → Subspecies

What are the 5 main kingdoms in paleontology?(5)

• Bacteria

• Protista

• Fungi

• Plantae

• Animalia

What are the kingdom bacteria?(4)

• Includes primitive organisms that do not have a well-differentiated nucleus and cytoplasm

• Includes bacteria and cyanobacteria

• Oldest known organisms from the fossil record

• Occur mostly as stromatolites

What is the kingdom protista?(3)

• Have a well-differentiated nucleus that can be simple or multiple

• Includes plant-like protistans(Algae)

• Includes animal-like protistans(Protistans)

What is the kingdom plantae?(3)

• Includes the land plants, which evolved as a result of the invasion of land in the Late Silurian

• They are autotrophic photosynthetic organisms

• Includes bryophytes, seedless plants, and plants with seeds

What are bryophytes?

• Small, non-vascular land plants

• Mosses

What is the kingdom animalia?(4)

• Multicellular eukaryotes

• Includes both invertebrate and vertebrate animals

• Have the highest rate of evolution among the five kingdoms, as evidenced by the fossil record

• Often have high movement capabilities and evolved high levels of intelligence

What kingdom does this belong to?(2)

Kingdom bacteria: stromatolites

What kingdom does this belong to?(2)

Kingdom protista: algae

What kingdom does this belong to?(2)

Kingdom protista: algae

What kingdom does this belong to?(2)

Kingdom protista: algae

What kingdom does this belong to?(2)

Kingdom protista: algae

What kingdom does this belong to?(2)

Kingdom protista: algae

What kingdom does this belong to?(2)

Kingdom protista: protistans

What kingdom does this belong to?(2)

Kingdom protista: protistans

What kingdom does this belong to?(2)

Kingdom protista: protistans

What kingdom does this belong to?(2)

Kingdom protista: protistans

What kingdom does this belong to?(2)

Kingdom protista: protistans

What kingdom does this belong to?(2)

Kingdom protista: protistans

What kingdom does this belong to?(2)

Kingdom protista: protistans

What kingdom does this belong to?(2)

Kingdom plantae: seedless plants

What kingdom does this belong to?(2)

Kingdom plantae: seedless plants

What kingdom does this belong to?(2)

Kingdom plantae: seedless plants

What kingdom does this belong to?(2)

Kingdom plantae: seeded plants

What kingdom does this belong to?(2)

Kingdom plantae: seeded plants

What kingdom does this belong to?(2)

Kingdom plantae: seeded plants

What kingdom does this belong to?(2)

Kingdom plantae: seeded plants

What kingdom does this belong to?(2)

Kingdom animalia: invertebrate animals