The Burgess Shale

Capsospongia undulata

A conical sponge with a coral-like appearance

Capsospongia undulata (ROM 53601). Individual missing the top section. Specimen length = 50 mm. Specimen wet – direct light. Walcott Quarry talus.

© Royal Ontario Museum. Photo: Jean-Bernard Caron

Taxonomy:

Kingdom: Animalia
Phylum: Porifera
Class: Demospongea (Order: Lithistida)
Remarks:

Capsospongia is interpreted to be an early orchoclad anthaspidellid at the base of the demosponges (Rigby, 1986). Demosponges, the same group that are harvested as bath sponges, represent the largest class of sponges today.

Species name: Capsospongia undulata
Described by: Walcott
Description date: 1920
Etymology:

Capsospongia – from the Latin capsa, “boxed” or “encapsulated,” and spongia, “sponge.”

undulata – from the Latin undulatus, “wavy,” after its undulating edges.

Type Specimens: Lectotype –USNM66480 in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
Other species:

Burgess Shale and vicinity: none.

Other deposits: none.

Age & Localities:

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

The Walcott Quarry on Fossil Ridge.

History of Research:

Brief history of research:

Originally described as Corralia undulata by Charles Walcott (1920) based on two specimens, Capsospongia was later redescribed as a separate genus (Rigby, 1986). A third specimen collected by a Royal Ontario Museum expedition was described in 2004 by Rigby and Collins.

Description:

Morphology:

Capsospongia is 35-75 mm tall and tapering up to around 20 mm in maximum width. Attached to the substrate by a narrow (3-4 mm wide) base, it has a curving, conical form with a wide open top (osculum) through which water would have been expelled. Combined with its annulated surface, which is ornamented by a series of low, length-parallel ridges and grooves, the organism somewhat resembles a rugose coral (Shapiro and Rigby, 2009). Major canals run parallel to the ridges, connected by a less ordered network of smaller channels within its thin walls, terminating into small pores (ostia) through which water would have been inhaled.

Abundance:

Capsospongia is known from a handful of specimens (Rigby and Collins, 2004).

Maximum Size:
75 mm

Ecology:

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

Capsospongia stood anchored to the sea floor. Particles of organic matter were extracted from the water as they passed through canals in the sponge’s wall.

References:

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.

SHAPIRO, R. S. AND J. K. RIGBY. 2009. First occurrence of an in situ anthaspidellid sponge in a dendrolite mound (Upper Cambrian; Great Basin, USA). Journal of Paleontology, 78(4): 645-650.

WALCOTT, C. D. 1920. Middle Cambrian Spongiae. Smithsonian Miscellaneous Collections, 67(6): 261-364.

Other Links:

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