The Burgess Shale

Crumillospongia frondosa

A large, purse-shaped sponge peppered with wide openings

Crumillospongia frondosa (USNM 35399) – Holotype. Incomplete specimen showing the large openings (ostia). Specimen diameter = 115 mm. Specimen wet – polarized light. Walcott Quarry.

© Smithsonian Institution – National Museum of Natural History. Photo: Jean-Bernard Caron


Kingdom: Animalia
Phylum: Porifera
Higher Taxonomic assignment: Demospongea (Order: Monaxonida)
Species name: Crumillospongia frondosa

A Hazeliid demosponge closely related to Hazelia (Rigby, 1986). Demosponges, the same group that are harvested as bath sponges, represent the largest class of sponges today.

Described by: Walcott
Description date: 1919

Crumillospongia – from the Latin crumilla, “money purse,” and spongia, “sponge,” thus, “purse-like sponge.”

frondosa – from the Latin frons, “leaf,” thus “leaf-like.”

Type Specimens: Holotypes –USNM35399 (C. frondosa),USNM66778 (C. biporosa), in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: C. biporosa Rigby, 1986 from the Walcott Quarry on Fossil Ridge.

Other deposits: An unidentified species from the Middle Cambrian Chengjiang biota (Chen et al., 1996).

Age & Localities:

Middle Cambrian, Bathyuriscus-Elrathina Zone (approximately 505 million years ago).
Principal localities:

Burgess Shale and vicinity: The Walcott Quarry on Fossil Ridge.

Other deposits: C. biporosa Rigby, 1986 from the Early Cambrian Niutitang biota in Guizhou Province (Wang et al., 2005).

History of Research:

Brief history of research:

Originally described from a single specimen as a member of the cyanobacteria genus Morania by Walcott (1919), Rigby (1986) re-described the organism as a sponge. Rigby also recognizing an additional species C. biporosa within the specimens described by Walcott as Hazelia delicatula in 1920. Additional material collected by the Royal Ontario Museum allowed the descriptions to be further refined (Rigby and Collins, 2004).



The sac-shaped body of the sponge resembles a leather purse, perforated by a regular-looking pattern of large and small holes. It anchored itself to the sea floor with a rounded base. Its spicules are straight and sometimes tufty, and approximately line up with one another to form a thatch-like skeleton. The walls of the sponge are peppered with millimeter-scale circular-to-elliptical canals of three distinct sizes terminating in pores (ostia). C. biporosa is much smaller than C. frondosa, and only has two size-classes of canal, which are also much smaller than the canals in C. frondosa.


Crumillospongia is rare in the Walcott Quarry where it represents less than 0.1% of the Walcott Quarry community (Caron and Jackson, 2008).

Maximum Size:
115 mm


Life habits: Epibenthic, Sessile
Feeding strategies: Suspension feeder
Ecological Interpretations:

Crumillospongia lived attached to or resting on the sea floor. Particles of organic matter were extracted from the water as they passed through canals in the sponge’s wall.


CARON, J.-B. AND D. A. JACKSON. 2008. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology, 258: 222-256.

CHEN, J. Y., G. Q. ZHOU, M. Y. ZHU AND K. Y. YEH. 1996. The Chengjiang biota a unique window of the Cambrian explosion. National Museum of Natural Science Taiwan, Taichung, 230 p.

RIGBY, J. K. 1986. Sponges of the Burgess Shale (Middle Cambrian), British Columbia. Palaeontographica Canadiana, 2: 1-105.

RIGBY, J. K. AND D. COLLINS. 2004. Sponges of the Middle Cambrian Burgess Shale and Stephen Formations, British Columbia. Royal Ontario Museum Contributions in Science, 1: 1-155.

WALCOTT, C. D. 1919. Cambrian Geology and Paleontology. IV. No. 5, Middle Cambrian Algae. Smithsonian Miscellaneous Collections, 67: 217-260.

WALCOTT, C. D. 1920. Middle Cambrian Spongiae. Smithsonian Miscellaneous Collections, 67: 261-364.

WANG, P.-L., Y.-L. ZHAO, X.-L. YANG AND R.-J. YANG. 2005. Crumillospongia biporosa (sponge) from the early Cambrian Niutitang biota in Guizhou Province. Acta Micropalaeontologica Sinica, 22: 196-201.

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