Choia is a genus of extinct demosponge ranging from the Cambrian until the Lower Ordovician periods. Fossils of Choia have been found in the Burgess Shale in British Columbia; the Maotianshan shales of China; the Wheeler Shale in Utah; and the Lower Ordovician Fezouata formation. It was first described in 1920 by Charles Doolittle Walcott.
Helmetia is an extinct genus of arthropod from the middle Cambrian. Its fossils have been found in the Burgess Shale of Canada and the Jince Formation of the Czech Republic.
Chancelloria is a genus of early animals known from the Middle Cambrian Burgess Shale, the Comley limestone, the Wheeler Shale, the Bright Angel Shale and elsewhere. It is named after Chancellor Peak. It was first described in 1920 by Charles Doolittle Walcott, who regarded them as one of the most primitive groups of sponges. However, they are currently thought to be member of the group Chancelloriidae. 178 specimens of Chancelloria are known from the Greater Phyllopod bed, where they comprise 0.34% of the community.
Yuknessia is an early pterobranch, known from the Burgess shale, the Chengjiang and the Wheeler shale. Long, unbranched fronds emerge from a central holdfast-like body covered in small conical plates. 23 specimens of Yuknessia are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. The genus contains two species: the type species Y. simplex and Y. stephenensis. It was originally interpreted as a green alga, and has since been reinterpreted it as a colonial pterobranch.
Dalyia is a pterobranch known from the middle Cambrian Burgess shale. It was previously interpreted as a red alga. It has smooth or faintly lineated stems, which branch into up to four equal branches at branching points. 37 specimens of Dalyia are known from the Greater Phyllopod bed, where they comprise 0.07% of the community.
Waputikia is a possible red alga of the middle Cambrian Burgess shale. It comprises a main stem about 1 cm across, with the longest recovered fossil 6 cm in length. Branches of a similar diameter emerge from the side of the main branch, then rapidly bifurcate to much finer widths. The fossils are smooth and shiny; no internal structure can be recognised. 10 specimens of Waputikia are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community.
Dictyophycus is a putative red alga of the middle Cambrian Burgess shale. While alive, it formed leaf-like lobes about 25mm across. The fossils do not preserve the leaf-like membrane, so only the sturdier "skeleton" is known; these are usually broken and detached from their holdfast. 308 specimens of Dictyophycus are known from the Greater Phyllopod bed, where they comprise 0.59% of the community.
Crumillospongia is a genus of middle Cambrian sponges known from the Burgess Shale and other localities from the Lower and Middle Cambrian. Its name is derived from the Latin crumilla and spongia ("sponge"), a reflection of its similarity to a small leathery money purse. That is, it has a saclike shape, and its wall has holes of two sizes, with a well-developed internal canal system. 49 specimens of Crumillospongia are known from the Greater Phyllopod bed, where they comprise 0.1% of the community.
Morania is a genus of cyanobacterium preserved as carbonaceous films in the Middle Cambrian Burgess Shale. it is present throughout the shale; 2580 specimens of Morania are known from the Greater Phyllopod bed, where they comprise 4.90% of the community. It is filamentous, forms sheets, and resembles the modern cyanobacterium Nostoc. It would have had a role in binding the sediment, and would have been a food source for such organisms as Odontogriphus and Wiwaxia.
Takakkawia is a genus of sponge in the order Protomonaxonida and the family Takakkawiidae. It is known from the Middle Cambrian Burgess Shale that reached around 4 cm in height. Its structure comprises four columns of multi-rayed, organic spicules that align to form flanges. The spicules form blade-like structures, ornamented with concentric rings.
The Phyllopod bed, designated by USNM locality number 35k, is the most famous fossil-bearing member of the Burgess Shale fossil Lagerstätte. It was quarried by Charles Walcott from 1911–1917, and was the source of 95% of the fossils he collected during this time; tens of thousands of soft-bodied fossils representing over 150 genera have been recovered from the Phyllopod bed alone.
Eiffelia is an extinct genus of sponges known from the Middle Cambrian Burgess Shale as well as several Early Cambrian small shelly fossil deposits. It is named after Eiffel Peak, which was itself named after the Eiffel Tower. It was first described in 1920 by Charles Doolittle Walcott. It belongs in the Hexactinellid stem group. 60 specimens of Eiffelia are known from the Greater Phyllopod bed, where they comprise 0.11% of the community.
Falospongia is a genus of sponge made up of radiating fronds, known from the Middle Cambrian Burgess Shale. Its name is derived from the Latin fala ("scaffold") and spongia ("sponge"), referring to the open framework of the skeleton. It superficially resembles Haplistion but is monaxial. 5 specimens of Falospongia are known from the Greater Phyllopod bed, where they comprise under 0.1% of the community.
Mackenzia is an elongated bag-like animal known from the Middle Cambrian Burgess Shale. It attached directly to hard surfaces, such as brachiopod shells. 14 specimens of Mackenzia are known from the Greater Phyllopod bed, where they comprise <0.1% of the community. Mackenzia was originally described by Charles Walcott in 1911 as a holothurian echinoderm. Later, Mackenzia is thought to be a cnidarian and appears most similar to modern sea anemones.
Micromitra is a genus of brachiopods known from the Middle Cambrian Burgess Shale. 160 specimens of Micromitra are known from the Greater Phyllopod bed, where they comprise 0.3% of the community.
Louisella is a genus of worm known from the Middle Cambrian Burgess Shale. It was originally described by Charles Walcott in 1911 as a holothurian echinoderm, and represents a senior synonym of Miskoia, which was originally described as an annelid. 48 specimens of Louisella are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. It has been stated to have palaeoscolecid-like sclerites, though this is not in fact the case.
Peronochaeta is a genus of annelid known from the Middle Cambrian Burgess Shale. 19 specimens of Peronochaeta are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. The genus was described by Conway Morris (1979) and re-examined by Eibye-Jacobsen (2004).
Pirania is an extinct genus of sea sponge known from the Middle Cambrian Burgess Shale and the Ordovician Fezouata formation. It is named after Mount St. Piran, a mountain situated in the Bow River Valley in Banff National Park, Alberta. It was first described in 1920 by Charles Doolittle Walcott. 198 specimens of Pirania are known from the Greater Phyllopod bed, where they comprise 0.38% of the community.
Selkirkia is a genus of predatory, tubicolous priapulid worms known from the Middle Cambrian Burgess Shale, Ogygopsis Shale and Puncoviscana Formation. 142 specimens of Selkirkia are known from the Greater Phyllopod bed, where they comprise 0.27% of the community. In the Burgess Shale, 20% of the tapering, organic-walled tubes are preserved with the worm inside them, whereas the other 80% are empty. Whilst alive, the tubes were probably vertical, whereas trilobite-occupied tubes are horizontal.
Wapkia is an extinct genus of sea sponge with radial sclerites, known from the Middle Cambrian Burgess Shale. It was first described in 1920 by Charles Doolittle Walcott. 32 specimens of Wapkia are known from the Greater Phyllopod bed, where they comprise 0.06% of the community.
