UNIVERSITY OF SOUTH ALABAMA · Primitive jawed fish . Plated, bony jawed fish . Bony jawed fish ....

GY 112: Earth History

Lectures 22, 23: Paleozoic Overview & the

Cambrian Explosion

Instructor: Dr. Douglas W. Haywick

UNIVERSITY OF SOUTH ALABAMA

Last time (before Spring Break)…

Proterozoic Fossils 1) Eukaryotes (Acritarchs) 2) Metazoans (Ediacarin Fauna)

(web notes 21)

Proterozoic Fossils

During the Archean, we saw the rise of the prokaryotes: •Small •No nucleus •DNA spread throughout the cell •Asexual reproduction •Could only be single-celled

Proterozoic Fossils

During the Proterozoic, something wonderful happens: the rise of the eukaryotes: •Larger (>0.06 mm) •A nucleus and organelles •DNA contained within the nucleus •Sexual reproduction •Could be multi-celled (metazoans)

Proterozoic Fossils

The first eukaryotes appeared around 2 GA. Acritarchs were small, single celled silica beasties that floated in the oceans (pelagic). They peaked in abundance at 750 MA and then went away…

0.1mm

Proterozoic Fossils

They are known as the Ediacarin Fauna And they are found around the world

http://www.cartage.org.lb/en/themes/Sciences

http://www.snowballearth.org/end.html

Proterozoic Fossils

More likely, severe environmental changes drives evolutionary adaptation. We need bad things to happen in order to evolve.

Today’s Agenda Paleozoic Overview

1) Time Frame 2) World Paleogeography

3) Key Tectonic events

(web notes 22, 23)

The Cambrian Explosion 1) Why a Cambrian “explosion”

2) Introducing our ancestors (GY 112 lab stuff)

Phanerozoic Time Frame

Eon Time Phanerozoic 550 MA to 0 MA Proterozoic 2.5 GA to 550 MA Archean 4.1 GA to 2.5 GA Hadean 4.6 GA to 4.1 GA

Phan

eroz

oic

Era Years Cenozoic (0 to 65 MA)

Mesozoic (65 to 245 MA)

Paleozoic (245 to 550 MA)

Phan

eroz

oic

Phanerozoic Time Frame

Paleozoic Time Frame Era Period

Paleozoic

Permian (245 to 286 MA)

Pennsylvanian (286 to 320 MA)

Mississippian (320 to 362 MA)

Devonian (362 to 418 MA)

Silurian (418 to 441 MA)

Ordovician (441 to 505 MA)

Cambrian (505 to 550 MA)

Neo- Proterozoic

American System


Paleozoic








Neo- Proterozoic

American System

Era Period

Paleozoic


Carboniferous

(286 to 362 MA)





Neo- Proterozoic

World System


Paleozoic








Neo- Proterozoic

Ediacaran (600 to 550 Ma)

American System

Era Period

Paleozoic


Carboniferous

(286 to 362 MA)





Neo- Proterozoic

Ediacaran (600 to 550 Ma)

World System

Paleozoic Paleogeography


Laurentia


Paleozoic video insert

Period North America Europe Asia/Gondwanna

Permian Alleghenian Orogeny* (SE)

Hercynian Orogeny Ural Orogeny

Pensylvannian

Mississippian Ouachita Orogeny (S) Ouachita equivalent (South America)

Devonian Acadian Orogeny* (E) Antler Orogeny (W)

Caledonian Orogeny

Silurian

Ordovician Taconic Orogeny* (NE)

Cambrian Broad deformation (Southern Gondwanna)

Paleozoic Tectonics (Key World Events)

The Cambrian Explosion

Not so much an explosion…


Not so much an explosion… …more of a shift…


Not so much an explosion… …more of a shift… to hard body parts

http://arjournals.annualreviews.org/na101/home/literatum/publisher/



What we know about the early development of all of the current phyla is limited to sites where we have lots of beasties preserved



What we know about the early development of all of the current phyla is limited to sites where we have lots of beasties preserved

Burgess Shale Fauna

Chengjiang Fauna

The Burgess Shale

The Burgess Shale

Burgess Shale Site

The Burgess Shale

The Burgess Shale

Pikaia gracilens (phylum: Chordata)

http://www.hao.ucar.edu/Public/models/pikaia/pikaia.gif

The Burgess Shale

Hallucigenia sparsa (phylum: Arthropoda)

http://www.karencarr.com/Images/Gallery/2004_gallery_hallucigenia.jpg

http://www.hrw.com/science/si-science/biology/animals/burgess/phallu.html

The Burgess Shale

Anomalocaris canadensis (phylum: Arthropoda?)

(Proto-Arthropod; Problematica) http://www.search4dinosaurs.com/burgess_shale.jpg

Limb

The Burgess Shale

Anomalocaris canadensis (phylum: Arthropoda?)

(Proto-Arthropod; Problematica) http://www.search4dinosaurs.com/burgess_shale.jpg

Jaws http://www.hrw.com/science/si-science

http://home.earthlink.net/~airdpacoima/sitebuildercontent/sitebuilderpictures/burgess__s.jpg

The Burgess Shale

Paleozoic Life Forms

Your Responsibilities

Reminder: You are going to have to become familiar with some of the major fossil groups (AKA Taxonomy).

Your Responsibilities

Know the stuff in bold text for the lab test This chart is on line (there is no need to write everything down!)

Phylum Sub-divisions Common names Age Ranges

Porifera Sponges Cambrian-Recent

Cnidaria Class: Anthozoa Subclass: Zoantharia Subclass: Tabulata Subclass: Rugosa

Corals & Anemones Scleratinian corals Tabulate corals Rugose (horn) corals

Triassic-Recent Cambrian-Permian Ordovician-Permian

Bryozoa Bryozoans Ordovician-Recent

Brachiopoda Class: Inarticulata Class: Articulata

Inarticulate brachiopods Articulate brachiopods

Cambrian-Recent Cambrian-Recent

Arthropoda Subphylum: Trilobita Subphylum: Crustacea Subphylum: Unirama Class: Myriapoda Class: Hexapoda Class: Arachnidea

Trilobite crabs, lobsters etc. millipedes, centipedes Insects Spiders

Cambrian-Permian Cambrian-Recent Mississippian-Recent Devonian-Recent Devonian-Recent

Know the stuff in bold text for the Final lab test

Phylum Sub-divisions Common names Age Ranges

Mollusca Class: Amphineura Class: Scaphopoda Class: Gastropoda Class: Bivalvia Class: Cephalopoda Order: Nautiloidea Order: Ammonoidea Order: Belemnoidea Order: Octopoda

chitons tusk shells snails bivalves (clam shells) Nautiloids Ammonites Belemnites Octopi

Cambrian-Recent Cambrian-Recent Cambrian-Recent Cambrian-Recent Cambrian-Recent Cambrian-Recent Dev.-Cretaceous Miss.-Early Tertiary

Echinodermata Class: Asteroidea Class: Echinoidea Class: Crinoidea Class: Blastoidea Class: Cystoidea

Starfish Urchin, biscuit, dollar crinoids blastoids cystoids

Ordovician-Recent Ordovician-Recent Cambrian-Recent Silurian-Permian Cambrian-Devonian

Hemichordata Class: Graptolithina Order: Graptoloidea Order: Dendroidea

graptolites dendroids

Cambrian-M. Ordovician-Silurian Cambrian-M.

Chordata Subphylum: Vertebrata Class: Agnatha Class: Acanthodii Class Placodermi Class: Osteichthyes Class: Chondrichthyes Class: Amphibia Class: Reptilia Subclass: Anapsida Subclass: Synapsida Subclass: Lepidosauria Subclass: Archosauria Class: Aves Class: Mammalia

(Chordates with bones) jawless fish Primitive jawed fish Plated, bony jawed fish Bony jawed fish Sharks and rays Amphibians Reptiles includes turtles mammal-like reptiles Lizards and snakes dinosaurs & crocodiles Birds mammals

Cambrian-Recent Silurian-Permian Silurian-Devonian Silurian-Recent Devonian-Recent Devonian-Recent Mississippian-Recent Mississippian-Recent Penn.-Jurassic Permian-Recent Triassic-Recent Jurassic-Recent Triassic-Recent

Today’s Homework 1. Study!

Next Time Lecture Test 2

GY 112: Earth History

Lectures 22, 23: Paleozoic Overview/ Cambrian Explosion

Instructor: Dr. Doug Haywick

[email protected]

This is a free open access lecture, but not for commercial purposes. For personal use only.

UNIVERSITY OF SOUTH ALABAMA · Primitive jawed fish . Plated, bony jawed fish . Bony jawed fish ....

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