Athyridida

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Athyridida
Temporal range: Lower Silurian - Early Jurassic
Uncitidae - Uncites gryphus.JPG
Fossil specimen of Uncites gryphus from Germany, Devonian age
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Brachiopoda
Class: Rhynchonellata
Order: Athyridida
Boucot, Johnson & Staton 1964
Suborders

Athyridida is an order of Paleozoic brachiopods included in the Rhynchonellata, which makes up part of the articulate brachiopods. [1] [2]

The Athyridida are the Rostrospracea of R.C Moore, 1952, [3] considered at that time to be a suborder of the Spiriferida. As with the Spiriferida, the Athyridida have outwardly directed spiral brachidia that support the lophophores on either side, but instead have non-plicate shells with rounded outlines and prominent beaks but almost no inner areas on the pedicle valve.

Athyridids began early in the Silurian, reached their greatest diversity in the following Devonian, and from then declined steadily until almost becoming extinct at the end of the Permian [3] The order rejuvenated somewhat during the Triassic, only to decline again until becoming extinct in the Early Jurassic. [4]

Athyris , Composita , and Meristella are representative genera. Three suborders have been defined.

Related Research Articles

<span class="mw-page-title-main">Jurassic</span> Second period of the Mesozoic Era 201-145 million years ago

The Jurassic is a geologic period and stratigraphic system that spanned from the end of the Triassic Period 201.4 million years ago (Mya) to the beginning of the Cretaceous Period, approximately 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified.

Zofiabaatar is a genus of extinct mammal from the Upper Jurassic period. It was a relatively early member of the extinct order Multituberculata within the suborder "Plagiaulacida". It lived in North America along with dinosaurs such as Diplodocus and Allosaurus.

<span class="mw-page-title-main">Spiriferida</span> Order of brachiopods

Spiriferida is an order of extinct articulate brachiopod fossils which are known for their long hinge-line, which is often the widest part of the shell. In some genera it is greatly elongated, giving them a wing-like appearance. They often have a deep fold down the center of the shell. The feature that gives the spiriferids their name ("spiral-bearers") is the internal support for the lophophore; this brachidium, which is often preserved in fossils, is a thin ribbon of calcite that is typically coiled tightly within the shell.

Eospirifer is a genus of extinct brachiopod in the class Rhynchonellata (Articulata) and the order Spiriferida. Their fossils occur most commonly in marine calcareous, microbialitic mudstones with extensive mudcracks or shelly packstones, generally mid-Silurian to early-Devonian in age.

<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">Terebratulida</span> Order of brachiopods

Terebratulids are one of only three living orders of articulate brachiopods, the others being the Rhynchonellida and the Thecideida. Craniida and Lingulida include living brachiopods, but are inarticulates. The name, Terebratula, may be derived from the Latin "terebra", meaning "hole-borer". The perceived resemblance of terebratulid shells to ancient Roman oil lamps gave the brachiopods their common name "lamp shell".

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

Rudists are a group of extinct box-, tube- or ring-shaped marine heterodont bivalves belonging to the order Hippuritida that arose during the Late Jurassic and became so diverse during the Cretaceous that they were major reef-building organisms in the Tethys Ocean, until their complete extinction at the close of the Cretaceous.

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

Orthida is an extinct order of brachiopods which appeared during the Early Cambrian period and became very diverse by the Ordovician, living in shallow-shelf seas. Orthids are the oldest member of the subphylum Rhynchonelliformea, and is the order from which all other brachiopods of this group stem. Physically they are usually strophic, with well-developed interareas. They also commonly have radiating ribs, sulcus, and fold structures. Typically one valve, often the brachial valve, is flatter than the other. The interior structure of the brachial valves are usually simple. In shape they are sub-circular to elliptical, with typically biconvex valves.

<span class="mw-page-title-main">Craniidae</span> Family of shelled animals

The Craniidae are a family of brachiopods, the only surviving members of the subphylum Craniiformea. They are the only members of the order Craniida, the monotypic suborder Craniidina, and the superfamily Cranioidea; consequently, the latter two taxa are at present redundant and rarely used.There are three living genera within Craniidae: Neoancistrocrania, Novocrania, and Valdiviathyris. As adults, craniids either live freely on the ocean floor or, more commonly, cement themselves onto a hard object with all or part of the ventral valve.

<span class="mw-page-title-main">Taxonomy of commonly fossilised invertebrates</span>

Taxonomy of commonly fossilised invertebrates is a complex and evolving field that combines both traditional and modern paleozoological terminology. This article provides an overview of various invertebrate taxa found in the fossil record, ranging from protists to arthropods. The taxonomy discussed is not exhaustive, but rather emphasizes invertebrates that are either frequently collected as fossils or are extinct. This includes groups that are significant in paleontological contexts, notably abundant in the fossil record, or have a high proportion of extinct species. For better understanding, special notations used in this context are explained below:

<span class="mw-page-title-main">Brachiopod</span> Phylum of marine animals also known as lamp shells

Brachiopods, phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major categories are traditionally recognized, articulate and inarticulate brachiopods. The word "articulate" is used to describe the tooth-and-groove structures of the valve-hinge which is present in the articulate group, and absent from the inarticulate group. This is the leading diagnostic skeletal feature, by which the two main groups can be readily distinguished as fossils. Articulate brachiopods have toothed hinges and simple, vertically oriented opening and closing muscles. Conversely, inarticulate brachiopods have weak, untoothed hinges and a more complex system of vertical and oblique (diagonal) muscles used to keep the two valves aligned. In many brachiopods, a stalk-like pedicle projects from an opening near the hinge of one of the valves, known as the pedicle or ventral valve. The pedicle, when present, keeps the animal anchored to the seabed but clear of sediment which would obstruct the opening.

<span class="mw-page-title-main">Rhynchonelliformea</span> Subphylum of brachiopods

Rhynchonelliformea is a major subphylum and clade of brachiopods. It is roughly equivalent to the former class Articulata, which was used previously in brachiopod taxonomy up until the 1990s. These so-called articulated brachiopods have many anatomical differences relative to "inarticulate" brachiopods of the subphyla Linguliformea and Craniformea. Articulates have hard calcium carbonate shells with tongue-and-groove hinge articulations and separate sets of simple opening and closing muscles.

<span class="mw-page-title-main">Rhynchonellata</span> Class of marine lamp shells

The Rhynchonellata is a class of Lower Cambrian to Recent articulate brachiopods that combines orders from within the Rhynchonelliformea with well developed pedicle attachment. Shell forms vary from those with wide hinge lines to beaked forms with virtually no hinge line and from generally smooth to strongly plicate. Most all are biconvex. Lophophores vary and include both looped and spiraled forms. Although morphologically distinct, included orders follow a consistent phylogenetic sequence.

<span class="mw-page-title-main">Pentamerida</span> Extinct order of shelled animals

Pentamerida is an order of biconvex, impunctate shelled, articulate brachiopods that are found in marine sedimentary rocks that range from the Middle Cambrian through the Devonian.

<i>Athyris</i> Genus of brachiopods

Athyris is a brachiopod genus with a subequally biconvex shell that is generally wider than long and a range that extends from the Silurian into the Triassic. Athyris is the type genus for the Athyrididae, which belongs to the articulate order Athyridida. R.C. Moore (1952) gives a shorter range, from the Mid Devonian to the Lower Mississippian.

<i>Meristella</i>

Meristella is an extinct genus of brachiopods found from the Late Silurian to the Late Devonian. They are characterized by a smooth oval shell and a prominent incurved beak on the pedicle valve. Meristella is placed in the family Meristellidae of the articulate brachiopod order Athyridida.

<i>Cyrtospirifer</i>

Cyrtospirifer is an extinct genus of brachiopods. The fossils are present in the Middle and Upper Devonian.

<span class="mw-page-title-main">Strophomenata</span> Extinct class of marine lamp shells

Strophomenata is an extinct class of brachiopods in the subphylum Rhynchonelliformea.

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

Productida is an extinct order of brachiopods in the extinct class Strophomenata. Members of Productida first appeared during the Silurian. They represented the most abundant group of brachiopods during the Permian period, accounting for 45-70% of all species. The vast majority of species went extinct during the Permian-Triassic extinction event, though a handful survived into the Early Triassic. Many productids are covered in hollow tubular spines, which are characteristic of the group. A number of functions for the spines have been proposed, including as a defensive mechanism against predators.

<span class="mw-page-title-main">Orthotetida</span> Extinct order of marine lamp shells

The orthotetides (Orthotetida) are an extinct order of brachiopods in the class Strophomenata. Though not particularly diverse or abundant relative to strophomenides (Strophomenida) or productides (Productida), orthotetides were nevertheless the longest-lasting order of strophomenates, surviving from the Middle Ordovician (“Llanvirn”) up until the Late Permian. Externally, many orthotetides are difficult to distinguish from strophomenides. Most fundamental differences between the two orders are internal: orthotetides have more elaborate cardinal processes and a greater diversity of shell microstructure.

References

  1. Classification des Brachiopoda
  2. Athyridida-Paleodb
  3. 1 2 Moore, Lalcker and Fischer, 1952, Invertebrate Fossils, McGraw-Hill
  4. Vörös, Attila; Kocsis, Ádám; Pálfy, József (1 September 2016). "Demise of the last two spire-bearing brachiopod orders (Spiriferinida and Athyridida) at the Toarcian (Early Jurassic) extinction event" (PDF). Palaeogeography, Palaeoclimatology, Palaeoecology. 457: 233–241. doi:10.1016/j.palaeo.2016.06.022 . Retrieved 29 October 2022.