20c 9918 (CONT.) becomes brownner or more Carbonaceous, shows rooting, or sometimes limonite stained pels, CUTANS (?) and often has a mat of plant matter (ferns dominate in lower 3 levels Sap. belyederensis at 9918 c) and angios dominate the mat at 9918d) that appears to represent the plant community at its time of burial by the succeeding loff. what does the increase in angio content upward signify? Evolutionary replacement of a-terus ferns early successional ferns by angios, or st. different ecological conditions, or increasing maturity (90s) the plant community.