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