trilobites
- Created by: ameliacooper28
- Created on: 07-04-20 15:11
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- trilobites
- cambrian
- planktonic/ pelagic
- cephalon and pygidium are same size - aids balance
- small (< 1 cm) - floats easily
- small thorax - aids balance
- benthic
- eyes on top of head suggests sea floor dweller
- large genal spines for support on sea floor
- planktonic/ pelagic
- ordovician
- burrower
- head shield - protected head from sediment
- large genal spines - could've been used as a shovel or used to keep the trilobite in sediment
- absence of eyes - no need for them due to deep water and lack of sunlight
- living on sediment, just below surface
- small and streamlined - water would've flowed easily across it
- eyes on top of stalks that were level with sea bed - would've been able to see if covered
- burrower
- protection
- many trilobites could curl up into a ball
- some evolved a series of sharp spines projecting from the back of the trilobite
- had a chitinous exoskeleton made of calcium phosphate and calcium carbonate - hard for preservation
- sized from 1 mm to 720 mm
- nektonic
- large glabella - probably filled with fat for buoyancy
- light exoskeleton - stays afloat easier
- streamlined - moves through water easily
- closest living relatives : horseshoe crabs, evolved in ordovician (450 ma)
- devonian
- probably benthic
- three pronged tridents attached to their cephalons
- sensory/radar function?
- disguise or protection?
- horns ?
- three pronged tridents attached to their cephalons
- lived in shallow, sun lit marine conditions
- eyes on turrets with a flange on top - active during day
- eyes had 500 lenses and 360 vision
- probably benthic
- cambrian
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