Mistaken Point - Fossil Ecosystems of North America: A Guide to the Sites and their Extraordinary Biotas - page 24

Assemblage, possessed a three-lobed body
with rounded lobes radiating from a
central rosette ( 27 ). Threefold symmetry is
rare in the animal kingdom, but does
occur in another Ediacaran genus,
Tribrachidium , first described from South
Australia. Triforillonia may be a holdfast or
a polyp-like organism, and was the first new
genus to be named from the New-
foundland Ediacaran fauna since Aspidella
in 1872; it is unknown elsewhere.

more common serial forms of curved
sausage-shaped or bead-like elements, are
similar to some described from Russia and
Ukraine and recently documented from
South Australia and Namibia. Some of the
serial forms were originally interpreted as
burrows, but are now thought by Jim
Gehling to be impressions of soft-bodied
bacterial colonies, algae, or egg masses
growing on the substrate.
First attempts to classify the Ediacaran
biota, by Sprigg (1947, 1949), Glaessner
(1961), and Glaessner and Wade (1966),
suggested a variety of extant phyla,
mainly the Cnidaria and Annelida, but
it was apparent that some Ediacaran
forms could not be placed in any
modern phylum. Later, Seilacher (1989)
removed the Ediacaran organisms from the
Metazoa altogether, preferring instead to
regard them as a separate kingdom
(Vendozoa) based on different functional
design from plants and animals. He looked
at the constructional morphology of the
organisms and suggested they may
have had internal hydrostatic skeletons,
their bodies gaining rigidity through
internal pressure, as in a car tyre.
Compartmentalization of the body

Thectardis
Another recently described endemic
taxon (Clapham et al ., 2004), this
triangular fossil has a raised rim and a
faintly segmented central depression. Its
authors consider that it was an elongate
cone up to 15 cm (6 in) tall, that may have
lived as a suspension feeding 'mat-sticker'
with its pointed base inserted into the
microbial bound sediment.

Others
Other unnamed frond-like fossils are
colloquially known as 'ostrich feathers',
'feather dusters' and 'xmas trees' and
await formal description. Rare pectinate,
network, triangular and radial forms, and

27

27 The trilobate fossil
Triforilloniafrom the
Fermeuse Formation at
Ferryland, Avalon Peninsula
GSC. Long axis 25 mm 1 in.