Evolutionary history of plants seed model is shared by basically all gymnosperms (literally: "naked seeds"), most of which encase their seeds in a woody cone or fleshy aril (the yew, for example), but none of which fully enclose their seeds. The angiosperms ("vessel seeds") are the only group to fully enclose the seed, in a carpel. Fully enclosed seeds opened up a new pathway for plants to follow: that of seed dormancy. The embryo, completely isolated from the external atmosphere and hence protected from desiccation, could survive some years of drought before germinating. Gymnosperm seeds from the Late Carboniferous have been found to contain
Archaeological sub-disciplines Archaeological sub-disciplines As with most academic disciplines, there are a number of archaeological sub-disciplines typically characterised by a focus on a specific method or type of material, geographical or chronological focus, or other thematic concern. Certain civilizations have attracted so much attention that their study has been specifically named. These sub-disciplines include "Assyriology" (Mesopotamia), "Classical archaeology" (Greece and Rome), "Etruscology" (Etruria), and "Egyptology" (Egypt). Another main division of archaeology distinguishes: In areas of semi-literacy the term A selective list of sub-disciplines distinguished by time-period or region of study might include: The following is a list of other sub-disciplines. Some of