''Protospongia'' is a genus of

Porifera Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a Basal (phylogenetics) , basal clade and a sister taxon of the Eumetazoa , diploblasts. They are sessility (motility) , sessile ...

described originally from the Middle

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

Menevia Formation of Porth-y-rhaw, St David’s,

Pembrokeshire Pembrokeshire ( ; ) is a Principal areas of Wales, county in the South West Wales, south-west of Wales. It is bordered by Carmarthenshire to the east, Ceredigion to the northeast, and otherwise by the sea. Haverfordwest is the largest town and ...

, SW Wales. ''Protospongia fenestrata'' Salter (1864) is the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

and, although based on only small fragments of the sponge skeleton, the arrangement of at least 3 orders of cross-shaped spicules (arranged in quadrules) is clearly evident (see Rushton & Phillips 1973, text fig. 2 for graphic). Six orders of spicule size were identified in the largest known example of ''Protospongia'' - a specimen of ''P. hicksi'' - from

Clare Island Clare Island ( or ''Oileán Chliara''), also historically Inishcleer, is a mountainous island guarding the entrance to Clew Bay in County Mayo, Ireland. Historically part of the kingdom of Umhaill, it is famous as the home of the 16th century p ...

, Co. Mayo,

Republic of Ireland Ireland ( ), also known as the Republic of Ireland (), is a country in Northwestern Europe, north-western Europe consisting of 26 of the 32 Counties of Ireland, counties of the island of Ireland, with a population of about 5.4 million. ...

(Rushton & Phillips,'' op. cit''.).

Remarks

''Protospongia hicksi'' is probably the only member of this genus of hexactinellid sponge to occur within the Burgess Shale and is rare in the Walcott Quarry where it represents about 0.24% of the community within the Greater

Phyllopod bed 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 later named Walcott Quarry), and was ...

(Caron and Jackson, 2008).. ''"Protospongia" rhenana'' Schlüter, 1892 from the Lower

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

(

Emsian The Emsian is one of three faunal stages in the Early Devonian Epoch. It lasted from 410.62 ±1.95 million years ago to 393.47 ±0.99 million years ago. It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after ...

)

Hunsrück Slate The Hunsrück () is a long, triangular, pronounced upland in Rhineland-Palatinate, Germany. It is bounded by the valleys of the Moselle-Saar (north-to-west), the Nahe (south), and the Rhine (east). It is continued by the Taunus mountains, past ...

of Germany, had previously been included in the genus due to the architecture of its spicules resembling that of ''P. hicksi''. Mehl (1996), however, has since transferred Schlüter's species to the genus ''Cyathophycus'' Walcott, 1879. Burgess Shale fossils of ''P. hicksi'' consist entirely of fragments and isolated, cruciform spicules, so the living animal's average to maximum size and growth habitus cannot be determined. If those ''"Protospongia"'' fossils outside of the Burgess Shale are of or closely related to ''P. hicksi'', then the growth habitus of various species would have been globular, such as ''P. tetranema'', to cup-shaped, like ''Cyathophycus rhenana''. The generic

homonym In linguistics, homonyms are words which are either; '' homographs''—words that mean different things, but have the same spelling (regardless of pronunciation), or '' homophones''—words that mean different things, but have the same pronunciat ...

''Protospongia''

Kent Kent is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Essex across the Thames Estuary to the north, the Strait of Dover to the south-east, East Sussex to the south-west, Surrey to the west, and Gr ...

, 1880, is a '' nom. illeg.'' because taxonomically the type species, ''Protospongia haeckelii'' Kent, is now regarded as belonging to '' Proterospongia'' Kent, 1881Kent, W. S. 1881. ''A manual of the Infusoria'': including a description of all known flagellate, ciliate and tentaculiferous Protozoa, British and foreign, and an account of the organisation and affinities of the sponges. Vol. 2(5) pp. 576-914, 11 figures, plates 33-40. London: D. Bogue. ''Proterospongia'' is a genus of single-celled aquatic organisms which form

colonies A colony is a territory subject to a form of foreign rule, which rules the territory and its indigenous peoples separated from the foreign rulers, the colonizer, and their '' metropole'' (or "mother country"). This separated rule was often or ...

. It belongs to the

choanoflagellate Choanoflagellates are a group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of animals. The name refers to the characteristic funnel-shaped "collar" of interconnected microvilli and ...

class and, interestingly, Choanoflagellates are a group of free-living unicellular and colonial

flagellate A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and the ...

eukaryotes The eukaryotes ( ) constitute the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of ...

considered to be the closest living relatives of

animals Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia (). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a ...

References

External links

Burgess Shale species 108
Hexactinellida genera Prehistoric sponge genera Burgess Shale sponges Paleozoic life of the Northwest Territories Hexactinellida {{paleo-sponge-stub