Fluvial Environments - Trace Fossils as Indicators of Sedimentary Environments - page 346

FIGURE 7 Core expression of the Taenidium ichnofabric in fluvial channels of subaerial delta-
plain deposits, Oligocene-Middle Miocene, Guafita Formation, Apure, Venezuela. (A) and (B)
Meniscate trace fossils in floodplain siltstone. (C) Crevasse-splay sandstone (lower interval) and
floodplain siltstone (upper interval), displaying colonization from the top of the sandstone layer into
the crevasse-splay deposit and totally reworked floodplain deposits.
burrows, arthropod trackways, horizontal burrows, simple vertical burrows,
simple horizontal trails, J-, U-, or Y-shaped burrows, rhizoliths, bipedal tri-
or tetradactyl footprints with thick digits, bilobed burrows/trails, and trough-
like reliefs ( Fig. 8 A). It is not clear if the dominance of invertebrate trace fossils
is a consequence of a bias in observation or if it reflects actual differences in
biodiversity or abundance of tracemakers and/or contrasting preservation of
invertebrate and vertebrate trace fossils. The major differences between the ana-
lyzed assemblages from channel-belt and floodplain settings are in abundance