The first archaeocyath fossils appear roughly 530 million years ago at the base
stage of the Lower Cambrian. During the subsequent 10
million years, the archaeocyaths were incredibly successful, diversifying into
an amazing array of forms and playing a dominant role in the construction of
the Earth's first reefs. As fantastic as their diversification was, there demise
was just as dramatic. By the end of that 10 million year period, these reef builders
had all but disappeared. The last recorded archaeocyath is a single species
from the Upper Cambrian of Antarctica.
Note that the illustrated number of archaeocyathan families present during the Lower Cambrian is roughly one half of the actual number known (an astonishing 120) due to space limitations.
Debrenne, F., A. Rozanov and A. Zhuravlev. 1990. Regular Archaeocyaths: Morpholggy, Ontogeny, Systematics, Biostratigraphy, Paleoecolgy, CNRS Editions, Paris. 218 p. + pl. XXXII.
Debrenne, F. and J. Vacelet. 1984. Archaeocyatha: Is the sponge model consistent with their structural organization? Palaeontographica Americana, 54: 358-369
Debrenne, F. and A. Zhuravlev. 1992. Irregular Archaeocyaths: Morpholggy, Ontogeny, Systematics, Biostratigraphy, Paleoecolgy, CNRS Editions, Paris. 212 p.+ pl. I-XXXVIII.
Debrenne, F. and A. Zhuravlev. 1996. Archaeocyatha, palaeoecology: a Cambrian sessile fauna. In A. Cherchi (ed.), Autecology of Selected Fossil Organisms: Achievements and Problems. Pp. 77-85. Boll. Soc. Paleont. Ital., Modena.
Kruse, P. D. 1990. Are archaeocyaths sponges, or are sponges archaeocyaths? Geological Society of Australia Special Publication, 16: 311-323.
Rowland, S. M. and R. A. Gangloff. 1988. Structure and Paleoecology of Lower Cambrian Reefs. Palaios, 3: 111-135.
Savarese, M. 1992. Functional analysis of archaeocyathan skeletal morphology and its paleobiological implications. Paleobiology 18(4): 464-480.