ESC 241 All Slide Content

What is evolution?

Change in populations over time

Difference between microevolution and macroevolution?

Microevolution = new species; Macroevolution = higher taxa (families, orders, etc.)

What causes genetic variation in evolution?

Mutations, crossing over, genetic recombination, gene flow

What is natural selection?

Individuals with advantageous traits survive and reproduce more

Basic formula of evolution?

Variation + selection + time

What is a transitional fossil?

Fossil showing intermediate traits between groups

Example of transitional fossil mentioned in class?

Ambulocetus (early whale ancestor)

What is stratigraphy?

Study of layered sedimentary rocks

Principle of original horizontality?

Sediments are deposited flat

Principle of superposition?

Oldest layers are at bottom, youngest at top

What is an unconformity?

Missing time in the rock record due to erosion or no deposition

Types of stratigraphy?

Lithostratigraphy, biostratigraphy, magnetostratigraphy, chronostratigraphy, chemostratigraphy, sequence stratigraphy

What is biostratigraphy?

Using fossils to date and correlate rock layers

What is faunal succession?

Fossils appear in a predictable order through time

What is FAD?

First Appearance Datum

What is LAD?

Last Appearance Datum

What is an index fossil?

Fossil that is widespread, abundant, short-lived, and used for dating rocks

What is a biozone?

Rock layer defined by fossil content

Types of biozones?

Range zone, interval zone, concurrent range zone, assemblage zone

What is biofacies?

Fossil assemblages reflecting environment rather than age

What are microfossils?

Microscopic fossils used for dating and environmental reconstruction

Main microfossil groups?

Foraminifera, radiolaria, diatoms, ostracods, conodonts, pollen, spores

What are foraminifera?

Single-celled protists with shells (tests)

Types of foraminiferal tests?

Agglutinated, calcareous (porcelaneous, hyaline), organic

Foraminifera chamber arrangement types?

Planispiral, trochospiral, biserial, uniserial

Where do foraminifera live?

Marine environments (planktonic and benthic)

Why are planktonic forams important?

Global correlation and climate reconstruction

What are diatoms?

Single-celled algae with silica frustules

Why are diatoms important?

Climate and environmental indicators

Age range of diatoms?

Jurassic to Recent

What are ostracods?

Small crustaceans with two calcareous valves

Ostracod ecology?

Freshwater and marine, mostly benthic

What are conodonts?

Phosphatic microfossils from early vertebrates

What are pollen and spores used for?

Terrestrial environmental reconstruction and dating

What are bryozoans?

Colonial filter-feeding marine animals with lophophores

Bryozoan colony forms?

Encrusting, erect, free-living

Bryozoan skeletal composition?

Calcareous or non-calcareous

Bryozoan ecology?

Mostly shallow marine, subtidal filter feeders

What are graptolites?

Extinct planktonic hemichordates used as index fossils

Graptolite lifestyle?

Planktonic filter feeders with colonial structures

Why are graptolites important?

Excellent index fossils with short stratigraphic ranges

What are brachiopods?

Marine filter-feeding animals with two shells (valves)

Brachiopod symmetry?

Symmetry divides the valves, not the body left-right

Brachiopod feeding structure?

Lophophore

Brachiopod lifestyle?

Mostly sessile, attached by pedicle

Brachiopod evolution trend?

High diversity in Paleozoic, decline after Permian

What are cephalopods?

Molluscs including nautiloids, ammonoids, and coleoids

Cephalopod lifestyle?

Active swimmers, predators

Cephalopod buoyancy mechanism?

Chambered shell with gas and siphuncle

Nautiloid characteristics?

Simple sutures, external chambered shell

Ammonoid characteristics?

Complex sutures, external coiled shell

Coleoid characteristics?

Internal or reduced shell

What is suture complexity trend?

Becomes more complex from Paleozoic to Mesozoic

What are echinoderms?

Marine animals with radial symmetry and water vascular system

Echinoderm symmetry?

Pentaradial (fivefold symmetry)

Echinoderm skeleton?

Calcareous ossicles forming internal skeleton

Water vascular system function?

Movement, feeding, respiration

Echinoderm classes?

Asteroidea, Ophiuroidea, Echinoidea, Holothuroidea, Crinoidea

What are crinoids?

Sessile echinoderms (sea lilies), filter feeders

What are echinoids?

Sea urchins and sand dollars

Echinoid types?

Regular (epifaunal) and irregular (burrowing)

What are trilobites?

Extinct arthropods with segmented exoskeletons

Trilobite growth method?

Molting (ecdysis)

Trilobite eyes?

Calcite compound eyes

Trilobite ecological types?

Benthic walkers and active swimmers

What are trace fossils?

Preserved evidence of organism activity (tracks, burrows, etc.)

Types of trace fossils?

Resting, crawling, feeding, dwelling, grazing, farming, escape, predation, equilibrium

What is ichnofacies?

Trace fossil assemblages reflecting environment

Why are trace fossils important?

Show behavior, environment, and sediment conditions