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.