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Unformatted text preview: s Shale, Canada Burgess Shale (~505 Ma)
Preservation: thin carbon or clay films on bedding planes of shale Organisms tumbled off a reef escarpment, fell into deep anoxic waters below, buried 17 2/19/2008 Opabinia
Fossil Reconstruction 5 eyes, vertical tail fin (probably swam), central grasping organ Wiwaxia ~2 cm
Moved along seafloor; tiny scales and long spines 18 2/19/2008 Anomalocaris ? Anomalocaris ? = bodies of shrimp-like organisms? 19 2/19/2008 Anomalocaris ! Animal ~1m = 3 ft. long Anomalocaris et al. Opabinia Wiwaxia ? 20 2/19/2008 Hallucigenia 2 mm Hallucigenia, 180o 2 mm 21 2/19/2008 Chengjiang Fauna (~520 Ma)
Discovered more recently Located in Yunnan China Yunnan, Preservation: thin carbon or clay films on bedding planes of shale, subsequently oxidized Many of the same organisms g as the Burgess Shale Phylum Chordata well represented Chengjiang outcrop Yunnanozoan, Yunnanozoan, an early chordate; likely ancestral to vertebrates (our lineage) Adaptive radiation
Within a few tens of millions of years, animals diversify at the phylum, class, and order l h l l d d level l A large-scale adaptive radiation largeadaptive Most phyla had few only species This phenomenon is unique (but adaptive radiations are not) What about these new phyla? Kingdom Phylum Class Order Family Genus Species 22 2/19/2008 S.J. Gould on the Burgess Shale
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This document was uploaded on 06/04/2008.
- Spring '08