Fossil Gallery

Home > Fossil Gallery > Dictyophycus

Dictyophycus gracilis

A possible algal frond with a delicate net-like structure

Image of Dictyophycus gracilis.

Get Adobe Flash player

Dictyophycus gracilis (USNM 83483e) – Syntype. Fragment associated with several other organisms including a couple of specimens of the arthropod Marrella splendens. Specimen length = 28 mm. Specimen dry – polarized light (left), wet – direct light (middle), wet – polarized light (right). Walcott Quarry.

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

Media 1 of 2 for Dictyophycus gracilis Photo
Media 2 of 2 for Dictyophycus gracilis Photo



Plantae (algae)?




Non applicable


No revisions to the affinities of this possible alga have been published since its original description.

Species name:

Dictyophycus gracilis

Described by:


Description date:



Dictyophycus – from the Greek diktyon, “net,” and phykos, “sea weed.”

gracilis – from the Latin gracil, “thin, slender or simple.” The genus and species names refer to the shape and structure of the organism.

Type Specimens:

Syntypes –USNM83483a-d in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.

Other species:

Burgess Shale and vicinity: none.

Other deposits: none.

Back to top



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

Back to top


Principal localities:

The Walcott Quarry on Fossil Ridge.

Back to top

History of Research

Brief history of research:

Dictyophycus was briefly described by Ruedemann (1931) as a possible alga. However, like all the other putative algae from the Burgess Shale, it awaits a formal redescription.

Back to top



Dictyophycus has a frond-like shape, with a delicate net composed of smooth fibers forming irregular to regular meshes. No organic material is preserved between fibers. The attachment structure is also rarely preserved and may have been broken during burial.


Dictyophycus is only known in the Walcott Quarry where it is relatively common in some layers representing 0.59% of the total counts of specimens (Caron and Jackson, 2008).

Maximum size:

50 mm

Back to top


Life habits:

Epibenthic, sessile

Feeding strategies:

Primary producer

Ecological Interpretations:

Dictyophycus probably lived attached to the sea floor within the photic zone.

Back to top



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

RUEDEMANN, R. 1931. Some new Middle Cambrian fossils from British Columbia. Proceedings of the United States National Museum. 79: 1-18.

Other links:


Back to top