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New Ediacaran quilted organism? (OT)



Not dinosaurs, but I was wondering if anyone would like to comment on this
out today:

Xiao, S., B. Shen, C. Zhou, G. Xie & X. Yuan. 2005. A uniquely preserved
Ediacaran fossil with direct evidence for a quilted bodyplan. Proceedings of
the National Academy of Sciences of the USA 102: 10227-10232.

"Ediacara fossils are among the oldest known macroscopic and complex life
forms. Their bodyplan, ecology, and phylogenetic affinities have been
controversial. On the basis of taphonomic observations, Seilacher
[Seilacher, A. (1989) Lethaia 22, 229­239] proposed that the core elements
of the Ediacara biota, the vendobionts, were constructed with serially or
fractally arranged quilts or tube-like units. However, anatomy of quilt
walls has been rarely reported, because most Ediacara fossils are preserved
as casts and molds in siliciclastic rocks with inadequate morphological
resolution. Here, we report an Ediacara form, uniquely preserved in situ and
in three dimensions with its organic walls cast by early diagenetic calcite,
from bituminous limestone of the 551- to 542-mega-annum Dengying Formation
of South China. Despite diagenetic tampering, serial sections show that the
Dengying form consists of biserially arranged, tube-like quilts, each with
two vertical side walls, a floor, a roof, and an open distal end.
Three-dimensional morphological complexity of the Dengying form excludes a
microbial interpretation but is broadly consistent with vendobionts. Unlike
classic frondose vendobionts sensu Seilacher, however, the Dengying form
probably lacked a smooth margin and had distally open quilts. It probably
lived procumbently at or near the water­sediment interface and shows
evidence for substrate utilization. Despite its uncertain phylogeny,
ontogeny, and functional biology, the Dengying form adds to Ediacaran
biodiversity, places key constraints on the ecology and extinction of
Ediacara organisms, and points to the need to explore an alternative
taphonomic window for Ediacara biology."

It's those 'open distal ends' that are bothering me. The 'quilts' are filled
with exactly the same sediment as the surrounding matrix, and the authors
interpret them to be hollow, with just the 'struts' comprising the actual
organism. To be honest, the figures look a heck of a lot like inorganic
structures to me, but the authors argue against it on the basis of their not
overlapping, and adjacent branches not encroaching on one another.
Any thoughts?