Biology:Phthipodochiton
| Phthipodochiton | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Polyplacophora |
| Order: | †Paleoloricata |
| Genus: | †Phthipodochiton Sutton and Sigwart, 2012[1] |
| Species: | †P. thraivensis
|
| Binomial name | |
| †Phthipodochiton thraivensis Sutton and Sigwart, 2012
| |
Phthipodochiton is an extinct genus of molluscs, known from several fossils from the upper Ordovician fauna of the Lady Burn Starfish beds of Girvan, Scotland.[1] It shows a mixture of aplacophoran body plan and polyplacophoran-like valves, and it is an informative fossil in the evolution of aculiferan mollusks.[1]
It was previously classified under the genus Helminthochiton,[2] but it has been reassigned to its own genus in 2012.[1]
Morphology
Phthipodochiton body is worm-like, with eight polyplacophoran-like valves but no true foot.[3] Head and tail valves are slightly smaller than the intermediate ones.[1] The only ornaments on the valves appear to be growth lines.[1] The body is also covered by a sheet of spicules ; no radula has been preserved.[1]
Life habits
Phthipodochiton was carnivorous, feeding on crinoids,[3] as shown by a fossil preserved with gut contents.[4] In contrast with modern chitons, Phthipodochiton probably did not creep on its foot but had a locomotion style similar to that of solenogastres.[1]
Taxonomy
Phthipodochiton shares similarities with genera as Alastega, Robustum and Septemchiton.[1] but it is sufficiently distinct from all of them to be considered a separate species. It is considered to belong to the aplacophoran stem lineage, along with Acaenoplax,[5] and it has also been placed close to Matthevia and the shelled aplacophoran Kulindroplax in phylogenetic analyses.[6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Sutton, M. D.; Sigwart, J. D. (2012). "A chiton without a foot". Palaeontology 55 (2): 401. doi:10.1111/j.1475-4983.2011.01126.x. Bibcode: 2012Palgy..55..401S.
- ↑ van Belle, R. A. (1981). Catalogue of Fossil Chitons. ISBN 90 6279 018 6.
- ↑ 3.0 3.1 "Aculifera". Palaeos. Palaeos. http://palaeos.com/metazoa/mollusca/aculifera/aculifera.html.
- ↑ Donovan, S. K.; Sutton, M. D.; Sigwart, J. D. (2010). "The last meal of the Late Ordovician mollusc 'Helminthochiton' thraivensis Reed, 1911, from the Lady Burn Starfish Beds, southwest Scotland". Geological Journal: n/a. doi:10.1002/gj.1286. https://pure.qub.ac.uk/ws/files/759573/Donovanetal_2010b.pdf.
- ↑ Sigwart, J. D.; Sutton, M. D. (Oct 2007). "Deep molluscan phylogeny: synthesis of palaeontological and neontological data". Proceedings of the Royal Society B: Biological Sciences 274 (1624): 2413–2419. doi:10.1098/rspb.2007.0701. PMID 17652065. For a summary, see "The Mollusca". University of California Museum of Paleontology. http://www.ucmp.berkeley.edu/taxa/inverts/mollusca/mollusca.php.
- ↑ Sutton, M. D.; Briggs, D. E. G.; Siveter, D. J.; Siveter, D. J.; Sigwart, J. D. (2012). "A Silurian armoured aplacophoran and implications for molluscan phylogeny". Nature 490 (7418): 94–97. doi:10.1038/nature11328. PMID 23038472. Bibcode: 2012Natur.490...94S.
Wikidata ☰ Q7188221 entry
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