chapter 21

psilotophyta

lack true leaves and roots

dichotomously branching stems

whisk ferns

rhizoids

especially mosses and liverworts

underside of thallus

to anchor plant and conduct water

outgrowth or root hair

ground pines

club mosses

branching stems

undivided leaves

low growing green plant resembles moss

relatives were first to colonize land

flowered eurasion plant

mint family

small and yellow

resembles pine appearance and smell

spores

microspores

megaspores

produced by seed plants

some fern allies

smaller of 2 kinds

developing in to male gametophyte

alternation of generation

life cycles of many lower plants

some invertebrates

a pattern of reproduction

alternation between two distinct forms

fossil

fossil compression

undergone physical compression

uncommon to find animals this way

preserved in sedimentary rock

very common to find plants this way

fossil imprint

as opposed to physical remains

soft sediment and include surface tracks

fossil w/ imprint or mark left by organism

later decay and subsurface burrows

fossil cast

bones deteriorate due to chemical reactions

minerals enter in to cavity

after a plant or animal dies

results in cast or mold fossil

fossil mold

flesh decays and bones deteriorate

cavity remains below the ground surface

when plant or animal dies, covered by sediment