Cribricyatha is an extinct class of sponge-like animals which lived in the early to mid-Cambrian Period (Tommotian to Botomian).
Description Cribricyatha were cup-shaped filter feeders similar to archaeocyathan sponges, with a skeleton composed of magnesium-rich calcite microgranules. The base is narrow, broadening upwards into a solid conical or semi-conical shell. In horizontal cross-section, the cup may be circular, elliptical, cardioid (heart-shaped), or quadrate (square-shaped).Treatise on Invertebrate Paleontology Part E, Revised. Porifera, Volumes 4 & 5: Hypercalcified Porifera, Paleozoic Stromatoporoidea & Archaeocyatha, liii + 1223 p., 665 figs., 2015, available here. .
All cribricyaths can be characterized by a series of peripterates, ribbon-like crests ringing around the outer surface of the shell. In cribricyaths of the order Cribricyathida, the peripterates may be supplemented by baculi, low ridges running parallel to the main shaft of the shell. Internally, the shell is hollow. Members of the superfamilies Pyxidocyathoidea and Akademiophylloidea have a smaller enclosed layer nested within the shell: the inner wall. When present, the inner wall is fused on one edge to the inner surface of the outer wall. The inner wall is porous and may have its own series of looping crests, known as striae. The cup develops from the outside-in, with the inner wall deposited after the outer wall.
Ecology Cribricyaths coexisted for some time with their archeocyathan relatives, but they were generally much smaller, with a maximum height of only 2 cm (0.8 inches) and a maximum diameter of only 2 mm. They were probably reef cryptobionts, meaning that they inhabited sheltered areas (such as the small crevices under or between rocks and reef-building organisms). Cribricyaths were endemic to a marine region equivalent to modern North Asia and Mongolia. Cribricyaths were usually subordinate to archaeocyathans as reef-building organisms, though they managed to be diverse or voluminous contributors for a few reef systems.
Taxonomy From the Treatise on Invertebrate Paleontology (Part E revised, Volumes 4–5, 2015):
Class Cribricyatha Vologdin, 1961 Order Cribricyathida Vologdin, 1961 Superfamily Conoidocyathoidea Vologdin, 1964 Family Conoidocyathidae Vologdin, 1964 Conoidocyathus Vologdin, 1964 [Atdabanian 1 – Botomian 3] Superfamily Pyxidocyathoidea Vologdin, 1964 Family Pyxidocyathidae Vologdin, 1964 Dolichocyathus Vologdin, 1964 [Botomian 1 – 3] Lucyathus Vologdin, 1957 [Atdabanian 1 – Botomian 3] Szecyathus Vologdin, 1957 [Atdabanian 2 – Botomian 3] Order Vologdinophyllida Radugin, 1964 Superfamily Vologdinophylloidea Radugin, 1964 Family Leibaellidae Jankauskas, 1965 Dubius Jankauskas, 1969 [Tommotian 3 – Botomian 1] Leibaella Jankauskas, 1964 [Tommotian 4 – Atdabanian 3] Ramifer Jankauskas, 1969 [Tommotian 2 – Atdabanian 4] Family Vologdinophyllidae Radugin, 1964 Manaella Jankauskas, 1964 [Atdabanian 1] Vologdinophyllum Radugin, 1962 [Atdabanian 1] Superfamily Akademiophylloidea Radugin, 1964 Family Akademiophyllidae Radugin, 1964 Akademiophyllum Radugin, 1964 [Atdabanian 1 – Botomian 1] Eriphyllum Radugin, 1966 [Atdabanian 1] Family Striatocyathidae Vologdin & Jankauskas, 1968 Achorocyathus Jankauskas, 1969 [Atdabanian 1 – 3] Rarocyathus Vologdin & Jankauskas, 1968 [Atdabanian 3 – Botomian 1] Striatocyathus Vologdin & Jankauskas, 1968 [Atdabanian 1 – Botomian 1]
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