BIOL360 Lecture 9: Lecture 9 notes
26 Mar 2018
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Molluscs: most common marine animals today, occupy the deepest ocean depths to intertidal zones to terrestrial forests, lakes and rivers. Halkieria cambrian, denmark; discovered in 1980s: worm-like, but has shells on both ends and the rest was covered in sclerites (hard; like scacles, has a foot, early type of mollusc. Shell grows logarithmically through golden spiral series with various twists and turns: fibonacci spiral or golden spiral logarithmic spiral whose growth factor is , gets wider further from its origin every twist. Shell is calcium carbonate calcite: aragonite (cid:523)crystal structure produces (cid:498)mother of pearl(cid:499)(cid:524, pearl production was primarily a defense mechanism formed from parasite and layering of aragonite. Rudist: weird bivalve that was common in mesozoic, late jurassic to late cretaceous, around tethys ocean; lived for a short period of time colonial, forming long tubes and has one large shell and one small one, produced reefs.
