Lecture 4

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Published on 26 May 2011
School
Simon Fraser University
Department
Biological Sciences
Course
BISC 316
May 25/11 – Lecture 4 – Bisc 316 Vertebrate Biology
Geological time Scale
- earth 4.5 by
- verterbrates
-Phanerozoic Eon (last 10-20%)
- Precambrian
1. Hadean 4.5 bya - formation of earth
2. Archean 3.8 bya - oldest recognized rocks
- oldest fossil is 3.5 bya
- origin of life - 4 bya
3. Proterozoic - 2.5 bya
- fossils of organisms - more complex than bacteria
- 2.2 bya - eukaryotic organisms, O2 producing organisms -> changes oceans
and atmosphere
- multicelllular organisms 1 bya
- large continental blocks
- end of Proterozoic - soft bodied organissms that were capable of secreting
articulating skeletal parts
Phanerozoic Eon
- 570 mya
- 99% of all described fossils
- Paleozoic, Mesozoic, Cenozoic Eras
- each era -> number of periods
- each period -> number of epochs
Late Cambrian
- Laurentia, Baltica, Kazakhstania, Siberia, China, Gondwana
- the first vertebrates -> early cambrian
- radiation of metazoan life
-many did not survive or leave descendants
Ordovician - jawless fish (Ostracoderms)
- vertebrates diversification
- radiation of marine animals
- no new phyla but 3X as many families
- many groups that dominated the rest of Paleozoic
www.notesolution.com
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Document Summary

May 25/11 lecture 4 bisc 316 vertebrate biology. Fossils of organisms - more complex than bacteria. 2. 2 bya - eukaryotic organisms, o2 producing organisms -> changes oceans and atmosphere. End of proterozoic - soft bodied organissms that were capable of secreting articulating skeletal parts. No new phyla but 3x as many families. Many groups that dominated the rest of paleozoic www. notesolution. com. Plants, fungi, small anthropods (detritors - millipedes), large anthropods (predators. Deep rooted plants -> chemical weathering of soils -> decrease co2. Late c. highly differentiated - glaciations and regional floral differences. 95% of all marine species, including 12 families of fishes (acanthodii) 49% of tetrapods (27 families) - mammal-like reptiles have heavy losses. Pangea breaks up (jurassic and cretaceous) => diversification of flora and fauna. End of cretaceous - extinction of 40% of tetrapod families (dinosaurs, pterosaurs, marine reptiles, some mammals and birds)