Conularida
indet
Phylum
Cnidaria (?), Conulariidae
Geological
Time: Mississippian (~320 m.y.a.)
Size (25.4
mm = 1 inch): Fossil is 80 mm long by 35 mm across (maximum)
Matrix: 110 mm by 145 mm
Fossil Site:
Heath Shale Formation,
Bear Gulch Limestone, Fergus County, Montana
Code: BGF325
Price: Sold
Description:
The Bear Gulch Limestone is a deposit of some 70 square km in extent
and 30 m in depth that has been a source of one of the most diverse
assemblages of fossil fish with some 110 species having been described
over the past 30 years. Most were new to science, and provided a
unique view of the marine environment of Mississippian times. Fine
preservation of both fish and invertebrates is a hallmark of these
deposits, presumably due to an anoxic depositional environment.
This specimen is a Conularid. Conulariids have been a subject of
speculation for over a century and a half. They ranged from the
Middle Ordovician to the Triassic. Exactly what they were is still
not settled. Because of their fourfold symmetry, they have often
been placed in the Cnidaria. However, their skeleton was very different
from anything known in the Cnidaria, and they may represent a separate,
extinct phylum The Conulariids had elongated, pyramidal exoskeletons,
made up of rows of calcium phosphate rods. Most were square or rectangular
in cross section, with prominent grooves at the corners. They lived
attached to hard objects by a flexible stalk, and often lived in
groups. They are thought to have been filter feeders; how they reproduced
is not known.
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