Tentaculites

Tentaculites
Temporal range: Early Ordovician – Late Devonian[1]
Tentaculitids from the Devonian of Maryland.
Scientific classification
Kingdom: Animalia
Phylum: Mollusca (?)
Class: Tentaculita
Order: Tentaculitida
Family: Tentaculitidae
Genus: Tentaculites
von Schlotheim 1820

Tentaculites is an extinct genus conical fossil of uncertain affinity, known from Lower Ordovician to Upper Devonian deposits[1] both as calcitic shells with a brachiopod-like microstructure[2] and carbonaceous 'linings'.[3][4] The "tentaculites" (i.e. tentaculita) are also referred to as the styliolinids.

Affinity

The taxonomic classification of tentaculitids is uncertain, but some group them with pteropods. They may also be related to other conical shells of uncertain affinity including cornulitids, microconchids and trypanoporids.[5] Their shell microstructure has warranted their comparison with the brachiopods and phoronids.[2][6]

Morphology

Tentaculitids have ribbed, cone-shaped shells which range in length from 5 to 20 mm. Some species septate; their embryonic shell, which is retained, forms a small, sometimes spherical, chamber.[4]

Ecology

Some species are inferred to have been planktonic.[7]

References

  1. 1.0 1.1 Traverse, A. (2007). "What Paleopalynology Is and Is Not". Paleopalynology. Topics in Geobiology 28. pp. 1–1. doi:10.1007/978-1-4020-5610-9_1. ISBN 978-1-4020-6684-9.
  2. 2.0 2.1 Towe, K. M. (1978). "Tentaculites: Evidence for a Brachiopod Affinity?". Science 201 (4356): 626–628. doi:10.1126/science.201.4356.626. PMID 17794124.
  3. Wood, G.D., Miller, M.A., and Bergstrom, S.M. 2004. Late Devonian (Frasnian) tentaculite organic remains in palynological preparations, Radom−Lublin region, Poland. Memoirs of the Association of Australian Palaeontologists 29: 253–258.
  4. 4.0 4.1 Filipiak, P.; Jarzynka, A. (2009). "Organic Remains of Tentaculitids: New Evidence from Upper Devonian of Poland". Acta Palaeontologica Polonica 54: 111. doi:10.4202/app.2009.0111.
  5. Vinn, O. (2010). "Adaptive strategies in the evolution of encrusting tentaculitoid tubeworms". Palaeogeography Palaeoclimatology Palaeoecology 292: 211–221. doi:10.1016/j.palaeo.2010.03.046. Retrieved 2014-01-11.
  6. Vinn, O.; Zatoń, M. (2012). "Phenetic phylogenetics of tentaculitoids — extinct problematic calcareous tube-forming organisms". GFF 134: 145–156. doi:10.1080/11035897.2012.669788. Retrieved 2014-06-11.
  7. LARSSON K. (1979). "Silurian tentaculitids from Gotland and Scania". Fossils and Strata, Oslo, vol. 11, 180 p.

Further reading

Tentaculitid from the New Creek Limestone (Lochkovian, Early Devonian) of New Creek, West Virginia.
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