Cambrian Earth History

The Paleozoic Era

Cambrian Plate Tectonics

The Cambrian “Explosion”

The Burgess Shale

The Chengjiang Fauna

hp://www.cyberpiggy.com/ Copyright Greg Carter The Paleozoic

The Paleozoic is the earliest, and longest, era of the Phanerozoic Eon.

The Cambrian is the earliest period of the Paleozoic.

All animal phyla with good fossil records (including chordates) first appear during the early Paleozoic, with almost all appearing during the Cambrian. Only one such animal phylum appears aer the Cambrian (bryozoans appear in the Ordovician).

The end of the Paleozoic is punctuated by the largest mass exncon in Earth’s long history. Cambrian Proterozoic

Proterozoic-Cambrian boundary Fortune Head, SE Newfoundland Dr. G. M. Narbonne points to the earliest occurrence of Trichophycus pedum hp://www.uni-wuerzburg.de/palaeontologie/Stuff/casu11.htm Copyright (C) G. Geyer, 1997 Cambrian Plate Tectonics

The Cambrian was a relatively quiet time for Laurentia, which drifted north toward the equator.

The Avalon Island Arc, Baltica and Siberia were closing in on Laurentia, but wouldn’t arrive until later in the Paleozoic.

The Carolina Terrane was forming well to the south, near the part of Gondwana that would eventually become Namibia.

http://jan.ucc.nau.edu/~rcb7/510NAt.jpg hp://www.uky.edu/KGS/educaon/images/ca_explo.gif The Cambrian Explosion

animals without animals with skeletons skeletons

“Sudden” appearance in the fossil record and rapid diversification of animals with hard parts

http://www.palaeos.com/Paleozoic/Cambrian/Cambrian.htm The Cambrian “Explosion” in Animal Diversity Global Changes Why??? Fluctuating carbon isotopes Caused by changes in primary productivity? Difficult to interpret. Increase in oxygen Gradual increase continues, but no jump Increase ∂34S Tied to redox, complex interaction of tectonic and biochemical controls. Difficult to interpret. Increase in phosphorite production Complex causality, tied to redox. Difficult to interpret.

http://www.palaeos.com/Paleozoic/Cambrian/Cambrian.htm

Why??? Global Changes Rising sea level Increased amount of shallow water habitat Development of macro-predators Perhaps the skeletons were for protection. However, single- celled protists also develop skeletons, and not all skeletons would have worked as armor.

Dozens of theories have been proposed, but no single theory has emerged as good enough to accept. New data is constantly being collected, so stay tuned…

http://www.palaeos.com/Paleozoic/Cambrian/Cambrian.htm Early Cambrian Period Tommotian and Adtabanian Stages

small, shelly fauna (SSF)

Small calcite and apatite shells, bits, pieces, and other skeletal elements While many clearly came from known groups (e.g., mollusks), most can’t be assigned with certainty. Very abundant, global distribution.

Basic Palaeontology . Benton M.J. & Harper D. 1997 Early Cambrian Period Tommotian and Adtabanian Stages

small, shelly fauna (SSF)

Insoluble residue of limestone samples with phosphatic tubes and sclerites of so-called "small shelly fossils". Late Tommotian, Malykan, Lena River, Siberia. Copyright (c) G. Geyer, 1997 http://www.uni-wuerzburg.de/palaeontologie/Stuff/casu8.htm The Middle Cambrian World

Lagerstatten – a fossil Burgess Shale Chengjiang deposit of unusual quality, frequently “soft parts” are preserved.

Greenland Three Tropical Lagerstatten

http://www.nmnh.si.edu/paleo/ Middle Cambrian Lagerstatten

Chengjiang� Burgess Shale

http://www.palaeos.com/Paleozoic/Cambrian/Cambrian.htm Burgess Shale

Algal Reef

Occasional mudslides washed animals from oxygenated shallow water to anoxic basin

http://www.burgess-shale.bc.ca/intro.htm Burgess Shale

Animals preserved as fossils

Animals with hard parts Stephen Mountain

http://www.burgess-shale.bc.ca/ Walcott Quarry

http://www.burgess-shale.bc.ca/ http://www-crewes.geo.ucalgary.ca/ Burgess Shale Fauna

Included taxa that are obviously members of familiar groups as well as weird and wacky extinct groups

http://www.dhushara.com/book/evol/edcamb.htm Phylum Arthropoda HUGE phylum

Sidneyia

Modern Isopod

http://www.orgbio.pdx.edu/people/faculty.html http://www.nmnh.si.edu/paleo/ Canadapsis Marella Phylum Arthropoda HUGE phylum

http://nmnhgoph.si.edu/paleo/shale/pfoslidx.htm Echmatocrinus

Early crinoid

Phylum Echinodermata Big phylum Komodo National Park, Indonesia Photographer: Ken Knezick

http://www.dc.peachnet.edu/~pgore/geology/geo102/burgess/burgess.htm Phylum Brachiopoda minor phylum in modern ocean Paleozoic diversity high

Micromitra Inarticulate brachiopod

Diraphora Articulate brachiopod

http://www.biology.ualberta.ca/courses.hp/zool250/ http://imperial.park.org/Canada/Museum/burgessshale/ Sponges

Vauxia Phylum Porifera large phylum http://www.acmereef.com/ http://geo.ucalgary.ca/~macrae/Burgess_Shale/ Phylum Annelida: Class Polychaeta Very large class of worms

Candida

http://www.nmnh.si.edu/paleo/ http://www.dc.peachnet.edu/~pgore/geology/geo102/burgess/burgess.htm http://www.badmovies.org/othermovies/deeprising/

Ottoia

Phylum Priapulida tiny phylum in modern ocean (~15 species) http://classes.seattleu.edu/biology/biol235/ http://www.nmnh.si.edu/paleo/ Superclass Trilobitomorpha Very large arthropod superclass, extinct at end of Paleozoic Hyolithids Trilobites

Incerta sedis Hyolithida Small group of what might have been mollusks, extinct at end of Paleozoic

http://www.nmnh.si.edu/paleo/ The weirdest of the weird turn out to be relatives of the modern onychophorans, or velvet worms

©1997 José A. Vargas

Modern Phylum Onychophora 16 genera

Aysheaia Hallucigenia http://rbt.ots.ac.cr/onych/photos/photos.htm http://nmnhgoph.si.edu/paleo/shale/pfoslidx.htm Hallucigenia Mary Parrish Reconstruction for the Smithsonian Museum of Natural History

Hallucigenia

http://www.nmnh.si.edu/paleo/PaleoArt Other Burgess Shale taxa defy categorization

Wiwaxia

http://nmnhgoph.si.edu/paleo/shale/pfoslidx.htm Opabinia Other Burgess Shale taxa defy categorization

http://nmnhgoph.si.edu/paleo/shale/pfoslidx.htm Copyright Greg Carter Burgess Shale Melodrama

Greg Carter

Editorial illustration for Science Fiction Age magazine

http://www.cyberpiggy.com/ Opabinia Mary Parrish Reconstruction for the Smithsonian Museum of Natural History

http://www.nmnh.si.edu/paleo/PaleoArt Anomalocaris

http://members.tripod.com/~Cambrian/

http://www.astrobiology.ucla.edu/

Other Burgess Shale taxa defy categorization Anomalocaris http://nicholnl.wcp.muohio.edu/NaturalSystems/NSEvolution3.html Anomalocaris Mary Parrish Reconstruction for the Smithsonian Museum of Natural History

Anomalocaris

http://www.nmnh.si.edu/paleo/PaleoArt Phylum Chordata Big phylum including vertebrates

Amphioxus Pikaia

The Burgess Shale fauna includes this small cephalochordate, a relative of the earliest chordate. http://news-info.wustl.edu/tips/2002/science-tech/vertebrate-invertebrate.html http://www.nmnh.si.edu/paleo/ http://www.dc.peachnet.edu/~pgore/geology/geo102/burgess/burgess.htm Chorus: It's a long way from amphioxus, it's a long way to us. It's a long way from amphioxus to the meanest human cuss. It's good-bye to fins and gill slits, and welcome lungs and hair. It's a long, long way from amphioxus, but we all came from there.

Oh, a fish-like thing appeared among the annelids one day, It hadn't any parapods or setae to display. It hadn't any eyes or jaws or ventral nervous chord. But it had a lot of gill slits and it had a notochord.

It wasn't much to look at and it scarce knew how to swim. And Nories was very sure it hadn't come from him. It's a Long The Molluscs wouldn't own it and the Arthropods got sore. So the poor thing had to burrow in the sand along the shore. Way From He burrowed in the sand before a crab could nip his tail. Amphioxus And he said, "Gill slits and myotomes are all to no avail." "I've grown some metapleural folds and sport an oral hood. But all these fine new characters don't do me any good."

He sulked awhile down in the sand, without a bit of pep; Then he stiffened up his notochord and said, "I'll beat 'em yet!" "Let them laugh and show their ignorance, I don't mind their jeers." "Just wait until they see me in a hundred million years."

"My notochord shall change into a chain of vertebra, And, as fins, my metapleural folds will agitate the sea." "My tiny dorsal nervous chord shall be a mighty brain. And the vertebrates shall dominate the animal domain." http://www.panix.com/~felicia/biopoem.html The Chengjiang fauna is an earlier Burgess Shale-like fauna, predating the Burgess Shale by ~12 Ma.

http://palaeo.gly.bris.ac.uk/Palaeofiles/Lagerstatten/chngjang/ Uncertain Affiliations Eldonia eumorphia Sun & Hou, 1987. Facivermis yunnanicus Hou & Chen, 1989. The Chengjiang fauna Rotadiscus grandis Sun & Hou, 1987. added considerably to Xidazoon stephanus Shu, Conway Morris & Zhang, 1999. Dinomischus isolatus Conway Morris, 1977. the bestiary of the Cambrian Explosion Lobopodia Hallucigenia sparsa Walcott, 1911. Porifera (sponges) Cardiodictyon calenudum Hou, Ramsköld & Bergström, 1991. Crumillospongia frondosa Walcott, 1919. Hallucigenia fortis Hou & Bergstöm, 1995. Choia carteri Walcott, 1920. Luolishania conicruris Hou & Chen, 1989. Hazelia palmata Walcott, 1920. Microdictyon sinicum Chen, Hou & Lu, 1989. Leptomitus zitteli Walcott, 1886. Onychodictyon ferox Hou, Ramsköld & Bergström, 1991. Tabakkawia lineata Walcott, 1920. Paucipodia inermis Chen, Zhou & Ramsköld, 1995. Allantospongia mica Rigby & Hou, 1995. Choiaella radiata Rigby & Hou, 1995. Leptomitella metta Rigby, 1983. Leptomitus teretiusculus Chen, Hou & Lu, 1989. Paraleptomitella dictyodroma Chen, Hou & Lu, 1989. Parvulonoda dubia Rigby & Hou, 1995. Algae Quadrolaminiella diagonalis Chen, Hou & Lu, 1990. Cambrorhytium major Walcott, 1908. Saetospongia densa Mehl & Reitner, 1993. Yuknessia simplex Walcott, 1919. Triticispongia diagonata Mehl & Reitner, 1993. Cinocylindrica yunnanensis Chen & Erdtmann, 1991. Halichondrites confusus Dawson, 1889. Megaspirella houi Chen & Erdtmann, 1991.

http://palaeo.gly.bris.ac.uk/Palaeofiles/Lagerstatten/chngjang/ Yuknessia Green algae

Marpolia Cyanobacteria

http://imperial.park.org/Canada/Museum/burgessshale/ http://www.gs-rc.org/GOODS/GOOD_3e.HTM

Xidazoon What is it? It’s a “whatsit” like several Burgess Shale creatures.

http://www.dol-ex.org/HTML/p4_2.html Peytoia nathorsti Walcott, 1911. Acanthomeridion serratum Hou, Chen & Lu, 1989. Almenia spinosa Hou & Bergström, 1997. Amplectobulua symbrachiaciata Hou, Bergström & Ahlberg, 1995. Anomalocaris saron Hou, Bergström & Ahlberg, 1995. Canadaspis laevigata Hou & Bergström, 1997. Chengjiangocaris longiformis Hou & Bergström, 1991. Cindarella eucalia Chen, Ramsköld, Edgecombe & Zhou, 1997. Fortiforceps foliosa Hou & Bergström, 1997. The most amazing Fuxianhuia protensa Hou, 1987. Isoxys paradoxus Hou, 1987. discoveries were the Jianfengia multisegmentalis Hou, 1987. Kuamaia lata Hou, 1987. new arthropods (right) Kuamaia muricata Hou & Bergström, 1997. Leanchoilia illecebrosa Hou, 1987. and the incredible Misszhouia longicaudata Zhang & Hou, 1985. Naraoia longicaudata Zhang & Hou, 1985. chordates Naraoia spinosa Zhang & Hou, 1985. Odaraia? eurypetala Hou & Sun, 1988. Retfacies abnormalis Hou, Chen & Lu, 1989. Rhombicalvaria acantha Hou, 1987. Saperion glumaceum Hou, Ramskouml;ld & Bergström, 1991. Sinoburius lumaris Hou, Ramskouml;ld & Bergström, 1991. Skioldia aldna Hou & Bergström, 1997. Chordates Squamacula clypeta Hou & Bergström, 1997. Cathaymyrus diadexus Shu et al. Urokoida aequalis Hou, Chen & Lu, 1989. Cathaymyrus haikouensis Luo & Hu, 2001. Xandarella spectaculum Hou, Ramsköld & Bergström, 1991. Cheungkongella ancestralis Shu, Chen, Han & Zhang, 2001. Yunnanocephalus yunnanensis Mansuy, 1912 Haikouella lanceolata Chen, Huang & Li, 1999. Alacomenaeus cambricus Simonetta, 1970. Haikouichthys eraicunensis Luo, Hu & Shu, 1999. Chuandianella ovata Li, 1975. Myllokunmingia fengjiaoa Shu, Zhang & Han, 1999. Eoredlichia intermedia Lu, 1941. Yunnanozoon lividum Hou, Ramsköld & Bergström, 1991. Isoxys auritus Jiang. Zhongxiniscus intermedius Luo & Hu, 2001. Kuanyangia sp. Hupé, 1953. Wutingaspis tingi Kobayashi, 1944.

http://palaeo.gly.bris.ac.uk/Palaeofiles/Lagerstatten/chngjang/ Yunnanozoon Oldest known hemichordate, sister group to the chordates

http://palaeo-electronica.org/2000_1/fossils/applic.htm http://www.gs-rc.org/GOODS/GOOD_3e.HTM

Cathaymyrus Oldest known cephalochordate, perhaps an older relative of Pikaia

http://www.dol-ex.org/HTML/p4_2.html http://www.gs-rc.org/GOODS/GOOD_3e.HTM

Myllokunmingia Oldest known member of the vertebrate clade!!! The next known vertebrate appears in the fossil record 50 Ma later.

http://www.dol-ex.org/HTML/p4_2.html