From Wikipedia, the free encyclopedia

Coeloscleritophora
Temporal range: Cambrian- Ordovician
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: incertae sedis
Class: Coeloscleritophora
Groups included

The Coelosclerithophorans are a polyphyletic group of organisms bearing hollow sclerites made of aragonite, and with a supposedly distinctive microstructure. [1]

Their skeletons may be homologous to those of the molluscs, [2] and Halkieria looks very much like a polyplacophoran. The shells of this group and the molluscs appear to have originated in the same fashion. [2] However, there are several reasons to doubt this relationship, [3] many of which may not pass muster. [4]

There are two groups within the coeloscleritophorans: the Sachitids, to which Halkieria and Wiwaxia belong, and the Chancellorids. The Ediacaran fossil Ausia has been touted as an ancestral 'intermediate' between both of these groups. [5]

These are common constituents of Lower Cambrian small shelly fossil assemblages.

References

  1. ^ Porter, S. M. (2008). "Skeletal Microstructure Indicates Chancelloriids and Halkieriids Are Closely Related". Palaeontology. 51 (4): 865–879. doi: 10.1111/j.1475-4983.2008.00792.x.
  2. ^ a b Bengtson, S. (1992). "The cap-shaped Cambrian fossil Maikhanella and the relationship between coeloscleritophorans and molluscs". Lethaia. 25 (4): 401–420. doi: 10.1111/j.1502-3931.1992.tb01644.x.
  3. ^ Yochelson, E. L. (1993). "Molluscan affinity of coeloscleritophorans". Lethaia. 26 (1): 47–48. doi: 10.1111/j.1502-3931.1993.tb01509.x.
  4. ^ Bengtson, S. (1993). "Molluscan affinity of coeloscleritophorans — reply". Lethaia. 26 (1): 48. doi: 10.1111/j.1502-3931.1993.tb01510.x.
  5. ^ Dzik, Jerzy (August 2009). "Possible Ediacaran Ancestry of the Halkieriids" (PDF). In Smith, Martin R.; O'Brien, Lorna J.; Caron, Jean-Bernard (eds.). Abstract Volume. International Conference on the Cambrian Explosion (Walcott 2009). Toronto, Ontario, Canada: The Burgess Shale Consortium (published 31 July 2009). ISBN  978-0-9812885-1-2.
From Wikipedia, the free encyclopedia

Coeloscleritophora
Temporal range: Cambrian- Ordovician
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: incertae sedis
Class: Coeloscleritophora
Groups included

The Coelosclerithophorans are a polyphyletic group of organisms bearing hollow sclerites made of aragonite, and with a supposedly distinctive microstructure. [1]

Their skeletons may be homologous to those of the molluscs, [2] and Halkieria looks very much like a polyplacophoran. The shells of this group and the molluscs appear to have originated in the same fashion. [2] However, there are several reasons to doubt this relationship, [3] many of which may not pass muster. [4]

There are two groups within the coeloscleritophorans: the Sachitids, to which Halkieria and Wiwaxia belong, and the Chancellorids. The Ediacaran fossil Ausia has been touted as an ancestral 'intermediate' between both of these groups. [5]

These are common constituents of Lower Cambrian small shelly fossil assemblages.

References

  1. ^ Porter, S. M. (2008). "Skeletal Microstructure Indicates Chancelloriids and Halkieriids Are Closely Related". Palaeontology. 51 (4): 865–879. doi: 10.1111/j.1475-4983.2008.00792.x.
  2. ^ a b Bengtson, S. (1992). "The cap-shaped Cambrian fossil Maikhanella and the relationship between coeloscleritophorans and molluscs". Lethaia. 25 (4): 401–420. doi: 10.1111/j.1502-3931.1992.tb01644.x.
  3. ^ Yochelson, E. L. (1993). "Molluscan affinity of coeloscleritophorans". Lethaia. 26 (1): 47–48. doi: 10.1111/j.1502-3931.1993.tb01509.x.
  4. ^ Bengtson, S. (1993). "Molluscan affinity of coeloscleritophorans — reply". Lethaia. 26 (1): 48. doi: 10.1111/j.1502-3931.1993.tb01510.x.
  5. ^ Dzik, Jerzy (August 2009). "Possible Ediacaran Ancestry of the Halkieriids" (PDF). In Smith, Martin R.; O'Brien, Lorna J.; Caron, Jean-Bernard (eds.). Abstract Volume. International Conference on the Cambrian Explosion (Walcott 2009). Toronto, Ontario, Canada: The Burgess Shale Consortium (published 31 July 2009). ISBN  978-0-9812885-1-2.

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