WERE THE EDIACARAN FOSSILS LICHENS

Ediacaran fossils are taphonomically similar to impressions of fossil plants common in quartz sandstones, and the relief of the fossils sugg ests that they were as resistant to compaction during burial as some k inds of Pennsylvanian tree trunks. Fossils of jellyfish are known from siderite nodules and fine-grained limestone, and even in these compac tion-resistant media were more compressed during burial than were the Vendobionta. Vendobionta were constructed of materials that responded to burial compaction in a way intermediate between conifer and lycopsi d logs. This comparative taphonomic study thus falsifies the concept o f Vendobionta as thin soft-bodied creatures such as worms and jellyfis h. Lichens, with their structural chitin, present a viable model for t he observed preservational style of Vendobionta, as well as for a vari ety of other features that now can be reassessed from this new perspec tive. The diversity of Ediacaran body plans can be compared with the v ariety of form in fungi, algae, and lichens. The large size (ca. 1 m) of some Ediacaran fossils is reasonable for sessile photosynthetic sym bioses, and much bigger than associated burrows of metazoans not prese rved. Microscopic tubular structures and darkly pigmented cells in per mineralized late Precambrian fossils from Namibia and China are also c ompatible with interpretation as lichens. The presumed marine habitat of Ediacaran fossils is not crucial to interpretation as lichens, beca use fungi and lichens live in the sea as well as on land.