{{Short description|Extinct genus of invertebrates}} {{Automatic taxobox | fossil_range = {{fossil range | Early Ordovician | Late Devonian | ref=<ref name="Traverse2007">{{Cite book | last1 = Traverse | first1 = A. | chapter = What Paleopalynology Is and Is Not | title = Paleopalynology | series = Topics in Geobiology | volume = 28 | pages = 1–43 | year = 2007 | isbn = 978-1-4020-6684-9 | doi = 10.1007/978-1-4020-5610-9_1}}</ref> }} | image = Tentaculites bellulus.jpg | image_caption = ''Tentaculites bellulus'' from the Middle Devonian of Wisconsin | taxon = Tentaculites | authority = von Schlotheim, 1820 | subdivision_ranks = Species | subdivision = * ''T. bellulus'' <small>Hall, 1876</small> * ''T. exaltatus'' <small>Talent, 1963</small> * ''T. grandis'' <small>Roemer, 1870</small> * ''T. oswegoensis'' <small>F.B. Meek & A.H. Worthen, 1865</small> }}
'''''Tentaculites''''' is an extinct genus of conical fossils of uncertain affinity, class Tentaculita, although it is not the only member of the class. It is known from Lower Ordovician to Upper Devonian deposits<ref name="Traverse2007" /> both as calcitic shells with a brachiopod-like microstructure<ref name="Towe1978">{{Cite journal | last1 = Towe | first1 = K. M. | title = Tentaculites: Evidence for a Brachiopod Affinity? | journal = Science | volume = 201 | issue = 4356 | pages = 626–628 | year = 1978 | pmid = 17794124 | doi = 10.1126/science.201.4356.626| bibcode = 1978Sci...201..626T | s2cid = 22806221 }}</ref> and carbonaceous 'linings'.<ref>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.</ref><ref name="Filipiak2009">{{Cite journal | last1 = Filipiak | first1 = P. | last2 = Jarzynka | first2 = A. | title = Organic Remains of Tentaculitids: New Evidence from Upper Devonian of Poland | journal = Acta Palaeontologica Polonica | volume = 54 | pages = 111–116 | year = 2009 | doi = 10.4202/app.2009.0111| doi-access = free }}</ref>
== Affinity== The taxonomic classification of tentaculitids is uncertain. Some grouped them with pteropods, but there is no modern support and only superficial similarity.{{who|<!--mentioned in following reference but basis for relationship not specified-->|date=December 2015}}<ref>Ager, 1963, Principles of Palaeontology</ref> They may also be related to other conical shells of uncertain affinity including cornulitids, ''Anticalyptraea'', microconchids and trypanoporids.<ref name='Vinn2010'>{{cite journal |author=Vinn, O. |title=Adaptive strategies in the evolution of encrusting tentaculitoid tubeworms |journal= Palaeogeography, Palaeoclimatology, Palaeoecology |year=2010 |volume=292 |issue=1–2 |pages=211–221 |url=https://www.researchgate.net/publication/222285765 |access-date = 2014-01-11 |doi=10.1016/j.palaeo.2010.03.046 |bibcode=2010PPP...292..211V }}</ref> Their shell microstructure has warranted their comparison with the brachiopods and phoronids,<ref name="Towe1978" /><ref name='VinnZaton2008'>{{cite journal | doi = 10.1080/11035897.2012.669788 | title = Phenetic phylogenetics of tentaculitoids — extinct problematic calcareous tube-forming organisms | year = 2012 | author = Vinn, O. | author2 = Zatoń, M. | journal = GFF | volume = 134 | issue = 2 | pages = 145–156 | s2cid = 83591938 | url = https://www.researchgate.net/publication/234023270 | access-date = 2014-06-11}}</ref> and the possible Ediacaran lophophorate ''Namacalathus''.<ref>1. Zhuravlev, A.Y., Wood, R.A., and Penny, A.M. (2015). Ediacaran skeletal metazoan interpreted as a lophophorate. Proc. R. Soc. B 282, 20151860. Available at: http://rspb.royalsocietypublishing.org/lookup/doi/10.1098/rspb.2015.1860.</ref>
== Morphology == thumb|right|Sketch of a ''Tentaculites ornatus'', Silurian. [[File:Tentaculitid041011.jpg|thumb|right|Tentaculitid from the New Creek Limestone (Lochkovian, Early Devonian) of New Creek, West Virginia.]] 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.<ref name="Filipiak2009" />
==Ecology== Some species are inferred to have been planktonic.<ref>{{cite journal|author=LARSSON K. |year=1979 |title=Silurian tentaculitids from Gotland and Scania|journal=Fossils and Strata |volume=11 |pages=180}}</ref>
== See also == *Mari Mari Group, fossil formation in the state of Amazonas of northwestern Brazil
== References == {{Reflist}}
==Further reading== {{Commons category|Tentaculites}} * Treatise on Invertebrate Paleontology, Part W - Miscellanea. ''Geological Society of America and University of Kansas Press'', 1962. LCCN 53012913
{{Taxonbar|from=Q4130259}} {{Authority control}}
Category:Devonian animals Category:Late Devonian animals Category:Tentaculita Category:Early Ordovician first appearances Category:Late Devonian genus extinctions Category:Silurian animals of North America Category:Paleozoic life of Ontario Category:Paleozoic life of Alberta Category:Paleozoic life of the Northwest Territories Category:Paleozoic life of Nova Scotia Category:Paleozoic life of Quebec Category:Paleozoic life of Yukon Category:Prehistoric animal genera