Marrella is an extinct genus of marrellomorph arthropod known from the middle Cambrian Burgess Shale of British Columbia. It is the most common animal represented in the Burgess Shale, with tens of thousands of specimens collected. Much rarer remains are also known from deposits in China.
Sidneyia is an extinct arthropod known from fossils found from the Early to the Mid Cambrian of China and the Mid Cambrian Burgess Shale of British Columbia, Canada.
Kootenia is a genus of trilobites of the family Dorypygidae. 118 specimens of Kootenia are known from the Greater Phyllopod bed, where they comprise 0.22% of the community. Its major characteristics are that of the closely related Olenoides, including medium size, a large glabella, and a medium-sized pygidium, but also a lack of the strong interpleural furrows on the pygidium that Olenoides has.
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.
Olenoides was a trilobite from the Cambrian period. Its fossils are found well-preserved in the Burgess Shale in Canada. It grew up to 10 cm long.
Elrathia is a genus of trilobite belonging to Ptychopariacea known from the mid-Cambrian of Laurentia. E. kingii is one of the most common trilobite fossils in the USA locally found in extremely high concentrations within the Wheeler Formation in the U.S. state of Utah. E. kingii has been considered the most recognizable trilobite. Commercial quarries extract E. kingii in prolific numbers, with just one commercial collector estimating 1.5 million specimens extracted in a 20-year career. 1950 specimens of Elrathia are known from the Greater Phyllopod bed, where they comprise 3.7% of the community.
"...trilobite occupied the exaerobic zone, at the boundary of anoxic and dysoxic bottom waters. E. kingii consistently occur in settings below the oxygen levels required by other contemporaneous epifaunal and infaunal benthic biota and may have derived energy from a food web that existed independently of phototrophic primary productivity. Although other fossil organisms are known to have preferred such environments, E. kingii is the earliest-known inhabitant of them, extending the documented range of the exaerobic ecological strategy into the Cambrian Period."
Ogygopsis is a genus of trilobite from the Cambrian of Antarctica and North America, specifically the Burgess Shale. It is the most common fossil in the Mt. Stephen fossil beds there, but rare in other Cambrian faunas. Its major characteristics are a prominent glabella with eye ridges, lack of pleural spines, a large spineless pygidium about as long as the thorax or cephalon, and its length: up to 12 cm.
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.
Ehmaniella is a genus of trilobite known from the Middle Cambrian Burgess Shale. 392 specimens of Ehmaniella are known from the Greater Phyllopod bed, where they comprise 0.74% 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.
Emeraldella is a genus of arthropod known from the Middle Cambrian of North America. The type species E. brocki was described in 1912 from the Burgess Shale. 21 specimens of Emeraldella are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. A re-study on the species was done in 2012. A second species E. brutoni is known from the Wheeler Shale, which was described in 2011. An additional specimen of E. brutoni was described in 2019, which revealed more of the anatomy. It has been placed as a basal member of the clade Vicissicaudata within Artiopoda, a group of arthropods containing trilobites and their relatives.
Hanburia gloriosa is a corynexochid trilobite known from the Middle Cambrian Burgess Shale. Four specimens of Hanburia gloriosa are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community.
Molaria is a genus of Cambrian arthropod, the type species M. spinifera is known from the Middle Cambrian Burgess Shale. 144 specimens of Molaria are known from the Greater Phyllopod bed, where they comprise 0.27% of the community. A second species M. steini was described from the Sirius Passet in Greenland in 2017.
Pagetia is a genus of small trilobite, assigned to the Eodiscinid family Pagetiidae and which had global distribution during the Middle Cambrian. The genus contains 55 currently recognized species, each with limited spatial and temporal ranges.
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.
Ptychagnostus is a member of the agnostida that lived during the Cambrian period. Ptychagnostidae generally do not exceed one centimetre in length. Their remains are rarely found in empty tubes of the polychaete worm Selkirkia. The genus probably ranged throughout the water column. It has two glabellar lobes, and three pygidial lobes.
Alokistocaridae is a family of ptychopariid trilobites that lived from the Botomian epoch of the Early Cambrian until the Late Cambrian. Alokistocarids were particle feeders and left small furrows which are occasionally preserved. Their remains are found worldwide. Elrathia kingii, one of the most collected trilobites in the world, is a typical alokistocarid.
Chancia is an extinct genus of Cambrian trilobite. It was a "fast-moving epifaunal detritivore" from Canada and the United States. Chancia was a particle feeder. Its major characteristics are a normal glabella but an enlarged cephalon due to a pre-glabellar field in front of the glabella, as well as developed eye ridges, medium-sized genal spines, and an extremely small pygidium.
Zacanthoides is an extinct Cambrian genus of corynexochid trilobite. It was a nektobenthic predatory carnivore. Its remains have been found in Canada, Greenland, Mexico, and the United States. Its major characteristics are a slender exoskeleton with 9 thoracic segments, pleurae with long spines, additional spines on the axial rings, and a pygidium that is considerably smaller than its cephalon.
Bathyuriscus is an extinct genus of Cambrian trilobite. It was a nektobenthic predatory carnivore. The genus Bathyuriscus is endemic to the shallow seas that surrounded Laurentia. Its major characteristics are a large forward-reaching glabella, pointed pleurae or pleurae with very short spines, and a medium pygidium with well-impressed furrows. Complete specimens have never reached the size of 7 cm predicted by the largest pygidium found. Bathyuriscus is often found with the free cheeks shed, indicating a moulted exoskeleton. An average specimen will in addition have a furrowed glabella, crescent-shaped eyes, be semi-circular in overall body shape, have 7 to 9 thoracic segments, and a length of about 1.5 inches.
