''Capsospongia'', formerly known as ''Corralia'' or ''Corralio'', is a middle Cambrian

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throug ...

genus known from 3 specimens in the

Burgess shale The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fos ...

. Its type and only species is ''Capsospongia undulata''. It has a narrow base, and consists of bulging rings which get wider further up the sponge, resulting in a conical shape. Its open top was presumably used to expel water that had passed through the sponge cells and been filtered for nutrients. Like most sponges, ''Capsospoingia'' had a spicular skeleton; long spicules parallel to the growth direction formed columns which were connected by shorter lateral spicules.

History

''Capsospongia undulata'' was named in 1920 by Charles Walcott as ''Corralia undulata''. However, the name was preoccupied by ''Corralia'' Roewer, 1913, a member of Opiliones. In 1955, de Laubenfels renamed the genus ''Corralio'', adopting an incorrect spelling of ''Corralia'' Walcott had used. In 1986 Keith Rigby established the new genus ''Capsospongia'' for it. In 2004, he and Desmond Collins described a third specimen. ''C. undulata'' intersects with the complicated taxonomic history of the

anomalocarids Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. They may be referred to as radiodonts, radiodontans, radiodontids, anomalocarids, or anomalocaridids, although the last two origina ...

. In 1911, Walcott had named two taxa, ''

Peytoia ''Peytoia'' is a genus of hurdiid radiodont that lived in the Cambrian period, containing two species, ''Peytoia nathorsti'' from the Miaolingian of Canada and '' Peytoia infercambriensis'' from Poland, dating to Cambrian Stage 3. Its two fron ...

'' and ''Laggania'', which he interpreted as a

jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...

and a

sea cucumber Sea cucumbers are echinoderms from the class Holothuroidea (). They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothu ...

respectively. In 1978,

Simon Conway Morris Simon Conway Morris (born 1951) is an English palaeontologist, evolutionary biologist, and astrobiologist known for his study of the fossils of the Burgess Shale and the Cambrian explosion. The results of these discoveries were celebrated ...

recognized that the mouthparts of ''Laggania'' closely resembled ''Peytoia'', but erroneously concluded that this was because ''Laggania'' was a composite fossil of a ''Peytoia'' and another organism, which he concluded was a sponge and suggested was probably a specimen of ''C. undulata''. However, it was subsequently determined that ''Laggania'' and ''Peytoia'' were partial specimens of a larger animal, a

radiodont Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. They may be referred to as radiodonts, radiodontans, radiodontids, anomalocarids, or anomalocaridids, although the last two original ...

, which now bears the name ''Peytoia''.

References

External links

* Tetractinomorpha Burgess Shale sponges Prehistoric sponge genera Fossil taxa described in 1920 Cambrian genus extinctions {{demosponge-stub