Halichondrites Temporal range: [1] | |
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Fossil detail of a Halichondrites elissa, on display at the Naturhistorisches Museum, Vienna. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Porifera |
Class: | Demospongiae |
Order: | † Protomonaxonida |
Family: | † Halichondritidae |
Genus: | † Halichondrites Dawson, 1889 |
Species | |
Halichondrites, sometimes mis-spelt Halicondrites [4] is an extinct genus of sea sponge known from the Middle Cambrian Burgess Shale. 7 specimens of Halichondrites are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. [5]
The genus Halichondrites was erected by John William Dawson in 1889, who described the species Halichondrites confusus from the Ordovician of Quebec at Little Métis.
In 1920, Charles Doolittle Walcott, considering H. confusus to be inadequately described, himself described Halichondrites elissa from the Middle Cambrian Burgess Shale, placing it as the type species of the genus. [2]
In 1936, Howell & Landes described and provisionally placed in the genus two further species from the Lower Ordovician of Wisconsin, Halichondrites? actiniformis and Halichondrites? robustus. [3]
Another species, "Halichondrites graphitiferus", was described by George Frederick Matthew in 1890 from the Precambrian of Saint John, New Brunswick. However, the organic nature of this species has been questioned; according to Miller (1987), who examined the holotype, the "spicules" described by Matthew are more likely a combination of scratches and cleavage on graphite. [6]
Vauxia is an extinct genus of demosponge that had a distinctive branching mode of growth. Each branch consisted of a network of strands. Vauxia also had a skeleton of spongin common to modern day sponges. Much like Choia and other sponges, Vauxia fed by extracting nutrients from the water.
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.
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.
Eldonia is an extinct soft-bodied cambroernid animal of unknown affinity, best known from the Fossil Ridge outcrops of the Burgess Shale, particularly in the 'Great Eldonia layer' in the Walcott Quarry. In addition to the 550 collected by Walcott, 224 specimens of Eldonia are known from the Greater Phyllopod bed, where they comprise 0.43% of the community. Species also occur in the Chengjiang biota, Siberia, and in Upper Ordovician strata of Morocco.
Hazelia is a genus of spicular Cambrian demosponge known from the Burgess Shale, the Marjum formation of Utah, and possibly Chengjiang. It was described by Charles Walcott in 1920.
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.
Cambrorhytium is an enigmatic fossil genus known from the Latham Shale (California), and the Chengjiang (China) and Burgess Shale lagerstätte. 350 specimens of Cambrorhytium are known from the Greater Phyllopod bed, where they comprise 0.7% of the community.
Acrothyra gregaria is a species of gregarious brachiopod known from the Middle Cambrian Burgess Shale. 253 specimens of Acrothyra are known from the Greater Phyllopod bed, where they comprise 0.5% of the community.
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.
Fieldospongia is a genus of sea sponge known from the Middle Cambrian Burgess Shale. Just five specimens of Fieldospongia are known from the Greater Phyllopod bed, where they comprise less than 0.1% of the community.
Hamptonia is an extinct genus of sea sponge known from the Middle Cambrian Burgess Shale and the Lower Ordovician Fezouata formation. It was first described in 1920 by Charles Doolittle Walcott. 48 specimens of Hamptonia are known from the Greater Phyllopod bed, where they comprise < 0.1% 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.
Mollisonia is an extinct genus of Cambrian arthropod. Species are known from the Burgess Shale, Langston Formation, and Wheeler Shale of North America, as well as the Chengjiang Biota of China. Twenty-one specimens of Mollisonia are known from the Greater Phyllopod bed, where they comprise less than 0.1% of the community. Remains possibly attributable to the genus are also known from the Ordovician Fezouata Formation of Morocco and Bøggild Fjord Formation in Greenland. An observation published in 2019 suggests this genus is a basal chelicerate, closer to crown group Chelicerata than members of Habeliida. It is suggested to be closely related to Corcorania, Urokodia, and Thelxiope, which together form the clade Mollisoniida, which are thought to be closely related to Chelicerata.
Leptomitus is a genus of demosponge known from the Middle Cambrian Burgess Shale. Its name is derived from the Greek lept ("slender") and mitos ("thread"), referring to the overall shape of the sponge. 138 specimens of Leptomitus are known from the Greater Phyllopod bed, where they comprise 0.26% of the community.
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.
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.
Protospongia is a genus of Porifera known from the Middle Cambrian Burgess Shale. 102 specimens of Protospongia are known from the Greater Phyllopod bed, where they comprise 0.19% of the community.
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.
Hazeliidae is an extinct family of spicular Cambrian sea sponges known from the Burgess Shale, the Marjum Formation of Utah, and possibly Chengjiang. It was described by Charles Walcott in 1920.
Diagoniella is a genus of sponge known from the Middle Cambrian Burgess Shale. 128 specimens of Diagoniella are known from the Greater Phyllopod bed, where they comprise 0.24% of the community.