Chancelloria
eros
Cambrian rocks frequently produce some of the
oddest-looking organisms anywhere in the fossil record. One distinctive
group of fossil organisms long known from Cambrian rocks is the
chancelloriids. Chancelloriids have bag-shaped bodies covered with
multirayed sclerites. They are often perceived as representing fossil
sponges (Porifera), but ultrastructural studies on chancelloriid skeletal
components show that they are a separate group.
Chancelloria eros scleritome (7.1 cm tall) - this is a commercially
prepared, complete scleritome of Chancelloria eros Walcott, 1920
(Animalia, Coeloscleritophora, Chancelloriidae) in hard, gray, slightly
calcareous mudshale. It comes from the “deep Wheeler Lagerstätte” (sensu
Robison, 1991 in The Early Evolution of Metazoa and the Significance
of Problematic Taxa), one of several famous soft-bodied fossil deposits in
Utah. Most chancelloriid fossils are isolated sclerites, typically
collected from acid residues of Cambrian limestones.
Stratigraphy: Wheeler Formation, upper Ptychagnostus atavus Interval-zone (=
lower Bolaspidella Assemblage-zone), upper Middle Cambrian.
Locality:
House Range, northern Millard County, western Utah, USA.