BISC 102 Lecture Notes - Lecture 7: Burgess Shale, Cambrian Explosion, Pikaia

• School: Simon Fraser University
• Department: Biological Sciences
• Course: BISC 102
• Professor: Erin Barley

Document Summary

Biological change slow for first 3. 5 billion years (3. 5 bya to 2. 1 bya for stromatolites to eukaryotes), more dramatic the last billion years (550 mya to ?? for ediacaran biota to ??) Animals = multicellular eukaryotes, chemoheterotrophs (ingests their food for energy and carbon), monophyletic. Cambrian explosion sudden dramatic appearance of diverse and complex animals in the fossil record. Cambrian fauna appearance of modern animal phyla, bilateral symmetry, diverse animal body plans (fossils in burgess shale, chengjian site) Burgess shale in b. c near lillooet; chengjian site in yunnan, china, predates burgess. Diversity of animal features: eyes, gills, hard exoskeletons, sensory appendages (antennae, tenta(cid:272)les(cid:895), jointed appendages, et(cid:272) . Pikaia: phylum chordata (like humans) because of notochord. Problematica: taxon phylum (cid:862)(cid:449)e don"t kno(cid:449) (cid:449)here to put this(cid:863) (cid:894)hallucigenia) Marble canyon (2014) 55 animal species, including 12 new taxa. Metaspriggina: phylum chordata; has notochord, paired eyes, post anal tail closer relative than pikaia.