Anabarella

Anabarella; Temporal range:
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	†Helcionelloida
Order:	†Helcionelliformes
Family:	†Helcionellidae
Genus:	†Anabarella
Species
	A. plana Vostokova, 1962 ; A. australis ;
Synonyms
	Planutenia ;

Anabarella is a species of bilaterally-flattened monoplacophoran mollusc,² with a morphological similarity to the rostroconchs.³ Its shell preserves evidence of three mineralogical textures on its outer surface: it is polygonal near the crest of the shell, subsequently changing to both spiny and stepwise.³ Its internal microstructure is calcitic and semi-nacreous.⁴ Its name reflects its provenance from Anabar, Siberia.³ It has been interpreted as ancestral to the rostroconchs,⁵ and has been aligned to the Helcionellidae.²

The genus is closely related to Watsonella, with which it bears many morphological similarities,³ including a laminar internal shell microstructure said to connect it with the early bivalves Fordilla and Pojetaia.⁶

References

Li, Luoyang; Zhang, Xingliang; Skovsted, Christian B.; Yun, Hao; Li, Guoxiang; Pan, Bing (2019). "Shell microstructures of the helcionelloid mollusc Anabarella australis from the lower Cambrian (Series 2) Xinji Formation of North China". Journal of Systematic Palaeontology. 17 (20): 1–11. Bibcode:2019JSPal..17.1699L. doi:10.1080/14772019.2018.1546236. S2CID 91387101.
Gubanov, A.; Skovsted, C.; Peel, J. (2004). "Anabarella australis (Mollusca, Helcionelloida) from the Lower Cambrian of Greenland". Geobios. 37 (6): 719–724. Bibcode:2004Geobi..37..719G. doi:10.1016/j.geobios.2003.05.009.
Kouchinsky, A. V. (1999). "Shell microstructures of the Early Cambrian Anabarella and Watsonella as new evidence on the origin of the Rostroconchia". Lethaia. 32 (2): 173–180. Bibcode:1999Letha..32..173K. doi:10.1111/j.1502-3931.1999.tb00537.x.
Vendrasco, Michael J.; Porter, Susannah M.; Kouchinsky, Artem; Li, Guoxiang; Fernandez, Christine Z. (2010). "New data on molluscs and their shell microstructures from the Middle Cambrian Gowers Formation, Australia". Palaeontology. 53 (1): 97–135. Bibcode:2010Palgy..53...97V. doi:10.1111/j.1475-4983.2009.00922.x.
Peel, J. S. (1991). "Functional Morphology of the Class Helcionelloida Nov., and the Early Evolution of the Mollusca". In Simonetta, A. M.; Conway Morris, S (eds.). The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press. pp. 157–177. ISBN 978-0-521-40242-2.
Vendrasco, M.J.; Checa, A.G.; Kouchinsky, A.V. (2011). "Shell microstructure of the early bivalve Pojetaia and the independent origin of nacre within the Mollusca". Palaeontology. 54 (4): 825–850. Bibcode:2011Palgy..54..825V. doi:10.1111/j.1475-4983.2011.01056.x.

[1] Li, Luoyang; Zhang, Xingliang; Skovsted, Christian B.; Yun, Hao; Li, Guoxiang; Pan, Bing (2019). "Shell microstructures of the helcionelloid mollusc Anabarella australis from the lower Cambrian (Series 2) Xinji Formation of North China". Journal of Systematic Palaeontology. 17 (20): 1–11. Bibcode:2019JSPal..17.1699L. doi:10.1080/14772019.2018.1546236. S2CID 91387101.

[Gubanov2004-2] Gubanov, A.; Skovsted, C.; Peel, J. (2004). "Anabarella australis (Mollusca, Helcionelloida) from the Lower Cambrian of Greenland". Geobios. 37 (6): 719–724. Bibcode:2004Geobi..37..719G. doi:10.1016/j.geobios.2003.05.009.

[Kouchinsky2007-3] Kouchinsky, A. V. (1999). "Shell microstructures of the Early Cambrian Anabarella and Watsonella as new evidence on the origin of the Rostroconchia". Lethaia. 32 (2): 173–180. Bibcode:1999Letha..32..173K. doi:10.1111/j.1502-3931.1999.tb00537.x.

[Vendrasco2010-4] Vendrasco, Michael J.; Porter, Susannah M.; Kouchinsky, Artem; Li, Guoxiang; Fernandez, Christine Z. (2010). "New data on molluscs and their shell microstructures from the Middle Cambrian Gowers Formation, Australia". Palaeontology. 53 (1): 97–135. Bibcode:2010Palgy..53...97V. doi:10.1111/j.1475-4983.2009.00922.x.

[5] Peel, J. S. (1991). "Functional Morphology of the Class Helcionelloida Nov., and the Early Evolution of the Mollusca". In Simonetta, A. M.; Conway Morris, S (eds.). The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press. pp. 157–177. ISBN 978-0-521-40242-2.

[Vendrasco2011-6] Vendrasco, M.J.; Checa, A.G.; Kouchinsky, A.V. (2011). "Shell microstructure of the early bivalve Pojetaia and the independent origin of nacre within the Mollusca". Palaeontology. 54 (4): 825–850. Bibcode:2011Palgy..54..825V. doi:10.1111/j.1475-4983.2011.01056.x.

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