Tentaculites

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Tentaculites
Temporal range: Early Ordovician – Late Devonian [1]
TentaculitidDevonian.jpg
Tentaculitids from the Devonian of Maryland.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Class: Tentaculita
Order: Tentaculitida
Family: Tentaculitidae
Genus: Tentaculites
von Schlotheim, 1820
Species
  • T. bellulusHall, 1876
  • T. exaltatusTalent, 1963
  • T. grandisRoemer, 1870
  • T. oswegoensis F.B. Meek & A.H. Worthen, 1865

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 [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.

Contents

Affinity

Tentaculites bellulus from the Middle Devonian of Wisconsin. Tentaculites bellulus.jpg
Tentaculites bellulus from the Middle Devonian of Wisconsin.

The taxonomic classification of tentaculitids is uncertain. Some grouped them with pteropods, but there is no modern support and only superficial similarity.[ who? ] [5] They may also be related to other conical shells of uncertain affinity including cornulitids, Anticalyptraea , microconchids and trypanoporids. [6] Their shell microstructure has warranted their comparison with the brachiopods and phoronids, [2] [7] and the possible Ediacaran lophophorate Namacalathus . [8]

Morphology

Sketch of a Tentaculites ornatus, Silurian. Tentaculites 2.jpg
Sketch of a Tentaculites ornatus, Silurian.
Tentaculitid from the New Creek Limestone (Lochkovian, Early Devonian) of New Creek, West Virginia. Tentaculitid041011.jpg
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. [4]

Ecology

Some species are inferred to have been planktonic. [9]

See also

Related Research Articles

The cloudinids, an early metazoan family containing the genera Acuticocloudina, Cloudina and Conotubus, lived in the late Ediacaran period about 550 million years ago. and became extinct at the base of the Cambrian. They formed millimetre-scale conical fossils consisting of calcareous cones nested within one another; the appearance of the organism itself remains unknown. The name Cloudina honors the 20th-century geologist and paleontologist Preston Cloud.

<span class="mw-page-title-main">Hyolitha</span> Palaeozoic lophophorates with small conical shells

Hyoliths are animals with small conical shells, known from fossils from the Palaeozoic era. They are at least considered as being lophotrochozoan, and possibly being lophophorates, a group which includes the brachiopods, while others consider them as being basal lophotrochozoans, or even molluscs.

<span class="mw-page-title-main">Tabulata</span> Order of extinct forms of coral

Tabulata, commonly known as tabulate corals, are an order of extinct forms of coral. They are almost always colonial, forming colonies of individual hexagonal cells known as corallites defined by a skeleton of calcite, similar in appearance to a honeycomb. Adjacent cells are joined by small pores. Their distinguishing feature is their well-developed horizontal internal partitions (tabulae) within each cell, but reduced or absent vertical internal partitions. They are usually smaller than rugose corals, but vary considerably in shape, from flat to conical to spherical.

<span class="mw-page-title-main">Hederellid</span> Superfamily of lophotrochs

Hederellids are extinct colonial animals with calcitic tubular branching exoskeletons. They range from the Silurian to the Permian and were most common in the Devonian period. They are more properly known as hederelloids because they were originally defined as a suborder by Bassler, who described about 130 species. Although they have traditionally been considered bryozoans, they are clearly not because of their branching patterns, lack of an astogenetic gradient, skeletal microstructure, and wide range in tube diameters. Work continues on assessing the true affinities of hederelloids, but they appear to be most closely related to phoronids and other lophophorates.

<i>Haplophrentis</i> Extinct genus of Cambrian organisms

Haplophrentis is a genus of tiny shelled hyolithid which lived in the Cambrian Period. Its shell was long and conical, with the open end protected by an operculum, from which two fleshy arms called helens protruded at the sides. These arms served to elevate the opening of the shells above the sea floor, acting like stilts.

<span class="mw-page-title-main">Conulariida</span> Order of cnidarians (fossil)

Conulariida are an extinct group of medusozoan cnidarians known from fossils spanning from the latest Ediacaran up until the Late Triassic. They are almost exclusively known from their hard external structures, which were pyramidal in shape and made up of numerous lamellae.

<i>Tentaculites oswegoensis</i> Extinct species of worm-like animal

Tentaculites oswegoensis is a small animal of unresolved phylogenetic affinities that has often been classified with molluscs or even with marine worms and has recently been interpreted as a lophophorate based on shell microstructure. The genus Tentaculites was named in 1820 by von Schlotheim. Tentaculites oswegoensis was named by 1877 and is known from the Upper Ordovician rocks of the Maquoketa Group. It ranged from Oswego, IL to possibly Kankakee River State Park (KRSP) in Will County, Illinois. At KRSP it appears in the basal Silurian of the Kankakee Formation but has not been found in the underlying Ordovician rocks.

The small shelly fauna, small shelly fossils (SSF), or early skeletal fossils (ESF) are mineralized fossils, many only a few millimetres long, with a nearly continuous record from the latest stages of the Ediacaran to the end of the Early Cambrian Period. They are very diverse, and there is no formal definition of "small shelly fauna" or "small shelly fossils". Almost all are from earlier rocks than more familiar fossils such as trilobites. Since most SSFs were preserved by being covered quickly with phosphate and this method of preservation is mainly limited to the late Ediacaran and early Cambrian periods, the animals that made them may actually have arisen earlier and persisted after this time span.

<span class="mw-page-title-main">Phoronid</span> Phylum of marine animals

Phoronids are a small phylum of marine animals that filter-feed with a lophophore, and build upright tubes of chitin to support and protect their soft bodies. They live in most of the oceans and seas, including the Arctic Ocean but excluding the Antarctic Ocean, and between the intertidal zone and about 400 meters down. Most adult phoronids are 2 cm long and about 1.5 mm wide, although the largest are 50 cm long.

<span class="mw-page-title-main">Cornulitida</span> Extinct order of Devonian organisms

Cornulitida is an extinct order of encrusting animals from class Tentaculita, which were common around the globe in the Ordovician to Devonian oceans, and survived until the Carboniferous. Organisms that may be the oldest cornulitids have been found in Cambrian sediments of Jordan.

<span class="mw-page-title-main">Tommotiid</span> Extinct order of brachiopods

Tommotiids are an extinct group of Cambrian invertebrates thought to be early lophophorates.

<span class="mw-page-title-main">Evolution of brachiopods</span> The origin and diversification of brachiopods through geologic time

The origin of the brachiopods is uncertain; they either arose from reduction of a multi-plated tubular organism, or from the folding of a slug-like organism with a protective shell on either end. Since their Cambrian origin, the phylum rose to a Palaeozoic dominance, but dwindled during the Mesozoic.

The cephalopods have a long geological history, with the first nautiloids found in late Cambrian strata.

<span class="mw-page-title-main">Microconchida</span> Extinct order of molluscs

The order Microconchida is a group of small, spirally-coiled, encrusting fossil "worm" tubes from the class Tentaculita found from the Upper Ordovician to the Middle Jurassic (Bathonian) around the world. They have lamellar calcitic shells, usually with pseudopunctae or punctae and a bulb-like origin. Many were long misidentified as the polychaete annelid Spirorbis until studies of shell microstructure and formation showed significant differences. All pre-Cretaceous "Spirorbis" fossils are now known to be microconchids. Their classification at the phylum level is still debated. Most likely they are some form of lophophorate, a group which includes phoronids, bryozoans and brachiopods. Microconchids may be closely related to the other encrusting tentaculitoid tubeworms, such as Anticalyptraea, trypanoporids and cornulitids.

<span class="mw-page-title-main">Tentaculita</span> Extinct class of uncertain affiliation

Tentaculita is an extinct class of uncertain placement ranging from the Early Ordovician to the Middle Jurassic. They were suspension feeders with a near worldwide distribution. For a more thorough discussion, see Tentaculites.

Trypanoporida is an extinct order of encrusting animals within Class Tentaculita, which were common in Devonian oceans. Their affinity is unknown; they have been placed among worms and corals. They appear to be closely related to other taxa of uncertain affinity, including the microconchids, cornulitids, and tentaculitids. Spirally coiled trypanoporids (Devonian) were most likely derived from the geologically older microconchids.

<i>Anticalyptraea</i>

Anticalyptraea is a fossil genus of encrusting tentaculitoid tubeworms from the Silurian to Devonian of Europe and North America . Anticalyptraea commonly encrust various invertebrate fossils such as stromatoporoids, rugose corals, bryozoans, brachiopods and crinoids, but they can also be common on the hardgrounds.

<i>Cornulites</i> Genus of cornulitid tubeworms

Cornulites is a genus of cornulitid tubeworms. Their shells have vesicular wall structure, and are both externally and internally annulated. They usually occur as encrusters on various shelly fossils. Their fossils are known from the Middle Ordovician to the Carboniferous.

Burrinjuckia is an ichnogenus of bioclaustrations. Burrinjuckia includes outgrowths of the brachiopod's secondary shell with a hollow interior in the mantle cavity of a brachiopod. Burrinjuckia was probably a parasite. They have a stratigraphic range from the Late Ordovician to the Devonian. The earliest Burrinjuckia species B. clitambonitofilia Vinn, Wilson and Toom, 2014 occurs in brachiopod Clitambonites squamatus from the Late Ordovician oilshale of Estonia.

<span class="mw-page-title-main">Olev Vinn</span> Estonian paleontologist (born 1971)

Olev Vinn is an Estonian paleobiologist and paleontologist.

References

  1. 1 2 Traverse, A. (2007). "What Paleopalynology Is and Is Not". Paleopalynology. Topics in Geobiology. Vol. 28. pp. 1–43. doi:10.1007/978-1-4020-5610-9_1. ISBN   978-1-4020-6684-9.
  2. 1 2 Towe, K. M. (1978). "Tentaculites: Evidence for a Brachiopod Affinity?". Science. 201 (4356): 626–628. Bibcode:1978Sci...201..626T. doi:10.1126/science.201.4356.626. PMID   17794124. S2CID   22806221.
  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. 1 2 Filipiak, P.; Jarzynka, A. (2009). "Organic Remains of Tentaculitids: New Evidence from Upper Devonian of Poland". Acta Palaeontologica Polonica. 54: 111–116. doi: 10.4202/app.2009.0111 .
  5. Ager, 1963, Principles of Palaeontology
  6. Vinn, O. (2010). "Adaptive strategies in the evolution of encrusting tentaculitoid tubeworms". Palaeogeography, Palaeoclimatology, Palaeoecology. 292 (1–2): 211–221. Bibcode:2010PPP...292..211V. doi:10.1016/j.palaeo.2010.03.046 . Retrieved 2014-01-11.
  7. Vinn, O.; Zatoń, M. (2012). "Phenetic phylogenetics of tentaculitoids — extinct problematic calcareous tube-forming organisms". GFF. 134 (2): 145–156. doi:10.1080/11035897.2012.669788. S2CID   83591938 . Retrieved 2014-06-11.
  8. 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.
  9. LARSSON K. (1979). "Silurian tentaculitids from Gotland and Scania". Fossils and Strata. 11: 180.

Further reading