Camenellan Temporal range:
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Reconstruction and life restoration of the camenellan Wufengella | |
Scientific classification
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Domain: | Eukaryota |
Kingdom: | Animalia |
Order: | † "Tommotiida" |
Informal group: | † Camenellans |
Genera | |
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The camenellans, consisting of the genera Camenalla, Dailyatia, Kennardia, Kelanella, Wufengella and Lapworthella, are a (probably monophyletic) group of Tommotiid invertebrates from the Cambrian period, reconstructed as sister to all others[ clarification needed] (plus brachiopods and phoronids). They are primarily known from isolated sclerites, but are believed to have a scleritomous, Halkieria-like construction. [2] [3] This was confirmed by the discovery of Wufengella, known from articulated remains, which showed camenellans to be mobile, worm-like animals. [4]
Dailyatia and Camenella have distinct dorsal (symmetrical) and lateral (asymmetric) sclerite morphologies. The same has been asserted for Lapworthella [5] even though that has not always been the common perception. [3]
It has been argued that Camenella, Kelanella and Lapworthella, assuming a slug-like anatomy, had an anterior 'head valve' followed by pairs of asymmetric valves running in pairs along their dorsal surface. [5]
The 'head valve' in Lapworthella - that is the bilaterally symmetric Morph A valve - is thought to have fused from two ontogenetically separate sclerites. [5] Dailyatia has a similar double-mounded structure at the tip of its A type sclerites. [2]
Growth rings in all are marked out by prominent external ridges. [2] [5]
Two families: [2]
Kennardiidae Laurie, 1986: three sclerite morphs, one of which (conventionally termed the A morph) is bilaterally symmetrical, the other two occurring in sinistral and dextral variants. Includes Kennardia and Dailyatia, and questionably Shetlandia
Lapworthellidae: sclerites occur in something of a morphological continuum, but essentially form a single type with a sinistral and dextral version, possibly with the anterior-most pair of sclerites fusing into a single bilaterally-symmetrical, dual-tipped sclerite.
Dailyatia species: [2]
Camenellan Temporal range:
| |
---|---|
![]() | |
Reconstruction and life restoration of the camenellan Wufengella | |
Scientific classification
![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Order: | † "Tommotiida" |
Informal group: | † Camenellans |
Genera | |
|
The camenellans, consisting of the genera Camenalla, Dailyatia, Kennardia, Kelanella, Wufengella and Lapworthella, are a (probably monophyletic) group of Tommotiid invertebrates from the Cambrian period, reconstructed as sister to all others[ clarification needed] (plus brachiopods and phoronids). They are primarily known from isolated sclerites, but are believed to have a scleritomous, Halkieria-like construction. [2] [3] This was confirmed by the discovery of Wufengella, known from articulated remains, which showed camenellans to be mobile, worm-like animals. [4]
Dailyatia and Camenella have distinct dorsal (symmetrical) and lateral (asymmetric) sclerite morphologies. The same has been asserted for Lapworthella [5] even though that has not always been the common perception. [3]
It has been argued that Camenella, Kelanella and Lapworthella, assuming a slug-like anatomy, had an anterior 'head valve' followed by pairs of asymmetric valves running in pairs along their dorsal surface. [5]
The 'head valve' in Lapworthella - that is the bilaterally symmetric Morph A valve - is thought to have fused from two ontogenetically separate sclerites. [5] Dailyatia has a similar double-mounded structure at the tip of its A type sclerites. [2]
Growth rings in all are marked out by prominent external ridges. [2] [5]
Two families: [2]
Kennardiidae Laurie, 1986: three sclerite morphs, one of which (conventionally termed the A morph) is bilaterally symmetrical, the other two occurring in sinistral and dextral variants. Includes Kennardia and Dailyatia, and questionably Shetlandia
Lapworthellidae: sclerites occur in something of a morphological continuum, but essentially form a single type with a sinistral and dextral version, possibly with the anterior-most pair of sclerites fusing into a single bilaterally-symmetrical, dual-tipped sclerite.
Dailyatia species: [2]