originally described as a sponge, some scientists have proposed
a new Class Coeloscleritophora for Chancelloria. This Class includes
Wiwaxiidae and other Cambrian sclerite-bearing animals.
is a very unusual specimen in that it has two carpoids attached
to it. The Chacelloria is small for the species, but is still a
very interesting piece. The Chancelloria from Utah were identified
pentacta, but are essentially identical to Chancelloria
eros, like those found in the Burgess Shale.
J.K. 1978 Porifera of the Middle Cambrian Wheeler Shale, from the
Wheeler Amphitheater, House Range, in western Utah. Journal of Paleontology
sponges: When people think of fossils, they normally think first
of dinosaurs, of trilobites, of ammonites - but usually not sponges,
yet they should. The humble sponge during modern times is represented
by some 9000 species spread across the globe and occupying essentially
all aquatic environments. Despite their ubiquitous dispersion, they
are of truly ancient origin. Indeed, sponges may well be the "Lucy"
of all of the Kingdom Animalia, since they were likely to have been
the first animals on Earth with cooperative cells. More accurately,
based on phylogenetic data from sponges and other creatures of ancient
origin, we can conjecture that sponges occupy the oldest and lowest
branch on the animal family tree. Because the higher branches have
introduced additional innovations that account for animals' rich
diversity, the common ancestor of all animals likely resembled modern
sponges much more closely than any other living animals. Sponges'
ability to grow different cell types performing different and cooperative
functions was an innovation that underlies virtually all subsequent
advances in the animal kingdom. While their cell signally pathways
are simplistic compared to most modern animals, it obviously was
robust enough for them to survive the numerous mass extinctions
on Earth since the origin of sponges in Precambrian time.
See: Utah Cambrian Explosion