This early Cambrian organism was critical in the formation of the first reef systems. These
reef-builders are considered to be an extinct type of sponge that disappeared around the end
of the middle cambrian period. In this relatively short span they were very abundandant and
have been used often to date rock strata because of their consistent abundance. There are
some who believe that arcaeocyathans were a type of coral, other animal, or even algae. It is
a very interesting, if controversial, group of organisms that shaped the natural history of
the early oceans.
About this specimen
This is a group of Archaeocyatha of undetermined species from the Lower Cambrian. They were found
in Puttapa, Southern Australia. I don't know the formation yet, so if you do, please contact me!
(above) Two pictures of my Archaeocyatha fossils. The fossils are oriented so that one
can see them from the top including the inner and outer walls and the internal partitions or "septa"
connecting the two walls. (below) A diagram of two archaeocyathans, showing the two walls, septa,
and the pores connecting the internal cavities, as well as the props that attached
them to rocks on some species, shown on the right specimen.
Diagram taken from:
Rich, Patricia V. ; Rich, Thomas H. ; Fendon, Mildred A. ; Fenton, Carroll L. : The Fossil Book - A Record of Prehistoric Life
Dover Publications, Inc. Mineola, NY - 1996 pg. 114