TAPHONOMY OF AN EDIACARAN FROND: CHARNIA FROM THE MISTAKEN POINT BIOTA OF NEWFOUNDLAND

The cosmopolitan Ediacaran frond Charnia represents one of the oldest, longest-ranging, and most familiar representatives of the Ediacara Biota. Charnia consisted of a leaf-like frond, composed of alternating primary branches, each made-up of multiple semi-rectangular secondary modular elements, tethered to the seafloor by a basal attachment bulb. In contrast with the younger and mainly fragmentary material known elsewhere, Mistaken Point Newfoundland is unique in preserving hundreds of complete Charnia fronds that represent the oldest specimens of this genus known anywhere (575-560 Ma). The original 3D morphology of Charnia can be understood through morphological and both landmark and traditional morphometric analyses of specimens in different preservational modes. These studies imply that Charnia cannot be regarded as a sheet-like organism, and Charnia is reinterpreted as being composed of several overlapping primary branches which are supported by an internal, possibly fluid-filled, organic skeleton. Morphologic, taphonomic, and ecologic studies at Mistaken Point imply that Charnia was a sessile, epibenthic frond that fed from suspension in this deep-water volcaniclastic setting.