Pelagodiscus

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Pelagodiscus
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Brachiopoda
Order: Discinida
Family: Discinidae
Genus: Pelagodiscus
Dall, 1908
Species:P. atlanticus
Binomial name
Pelagodiscus atlanticus
(King, 1868)

Pelagodiscus is a monospecific genus of discinid brachiopods. Silica tablets leave a distinctive tesselating imprint on the inner surface of its shell. [1]

Brachiopod Phylum of marine animals also known as lamp shells

Brachiopods, phylum Brachiopoda, are a group of lophotrochozoan 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 groups are recognized, articulate and inarticulate. The word "articulate" is used to describe the tooth-and-groove features of the valve-hinge which is present in the articulate group, and absent from the inarticulate group. This is the leading diagnostic feature (fossilizable), by which the two main groups can be readily distinguished. Articulate brachiopods have toothed hinges and simple opening and closing muscles, while inarticulate brachiopods have untoothed hinges and a more complex system of muscles used to keep the two valves aligned. In a typical brachiopod a stalk-like pedicle projects from an opening in one of the valves near the hinges, known as the pedicle valve, keeping the animal anchored to the seabed but clear of silt that would obstruct the opening.

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Lirae are fine lines or ridges that are a sculptural feature of the outside of the shells of various animals. The term is commonly applied to the shells of molluscs such as gastropods, bivalves and nautiloids. It can also be used to describe similar sculpture on the surface of the shells of brachiopods.

<i>Tentaculites</i>

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 both as calcitic shells with a brachiopod-like microstructure and carbonaceous 'linings'. The "tentaculites" are also referred to as the styliolinids.

Lingulata class of brachiopods

Lingulata is a class of brachiopods, among the oldest of all brachiopods having existed since the Cambrian period. They are also among the most morphologically conservative of the brachiopods, having lasted from their earliest appearance to the present with very little change in shape. Shells of living specimens found today in the waters around Japan are almost identical to ancient Cambrian fossils.

Craniata (brachiopod) class of brachiopods

Craniata is a class of brachiopods originating in the Cambrian period and still extant today. They have calcitic inarticulated shells that are subcircular in outline. This class of brachiopods has an unsupported lophophore and is always attached to a hard substrate in the fossil record. This hard substrate is usually another brachiopod. The plicae from the host brachiopod will then appear within the shell of the craniata.

Rhynchonellida order of brachiopods

The taxonomic order Rhynchonellida is one of the two main groups of living articulate brachiopods, the other being the order Terebratulida. They are recognized by their strongly ribbed wedge-shaped or nut-like shells, and the very short hinge line.

The Obolellata are a class of Rhynchonelliform brachiopods with two orders, Obolellida and Naukatida. They are essentially restricted to the lower-middle Cambrian.

Linguliformea subphylum of brachiopods

Linguliformea is a subphylum of inarticulate brachiopods. These were the earliest of brachiopods, ranging from the Cambrian into the Holocene. They rapidly diversified during the Cambrian into the Ordovician, but most families became extinct by the end of the Devonian.

Margaret Jope (1913–2004) was a Scottish biochemist, born as Henrietta Margaret Halliday in Peterhead, Scotland.

<i>Discinisca</i> genus of brachiopods

Discinisca is a genus of brachiopods with fossils dating back from the Early Devonian to the Pliocene of Africa, Europe, North America, and New Zealand.

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.

<i>Anomia</i> (bivalve) genus of molluscs

Anomia is a genus of saltwater clams, marine bivalve mollusks in the family Anomiidae. They are commonly known as jingle shells because when a handful of them are shaken they make a jingling sound, though some are also known as saddle oysters.

Rhynchonelliformea subphylum of brachiopods

Rhynchonelliformea is the name now given to the articulate brachiopods, Class Articulata, revised as a subphylum. Articulate brachiopods are those with hard, articulated shells with a simple set of opening and closing muscles.

Discinoidea is a superfamily of Discinid brachiopods. For discussion of Discinid taxonomy, see Discinidae.

Discinidae is a family in the brachiopod superfamily Discinoidea. Unlike most brachiopods, which have uniformly calcitic or phosphatic shells, modern-day discinids incorporate tablets of silica into their valves. These are covered with vesicles into which the siliceous tablets are cemented, much like a closely packed mosaic, and held together with apatite. These vesicles eventually degrade, but nevertheless still leave an imprint on the shell itself. It has been suggested that this siliceous biomineralisation might also have occurred amongst some of the earliest Paleozoic brachiopods because similar patterns of shell imprints have been observed amongst them too.

Mickwitziids are a Cambrian group of shelly fossils with originally phosphatic valves, belonging to the Brachiopod stem group, and exemplified by the genus Mickwitzia – the other genera are Heliomedusa and Setatella. The family Mickwitziidae is conceivably paraphyletic with respect to certain crown-group brachiopods.

<i>Meristella</i> genus of brachiopods

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>Strophomena</i> genus of brachiopods (fossil)

Strophomena is a genus of brachiopods belonging to the order Strophomenida family Strophomenidae, named by Rafinesque in 1824. They were stationary epifaunal suspension feeders.

<i>Argyrotheca</i> genus of brachiopods

Argyrotheca is a genus of very small to minute lampshells. All species share a large pedicel opening, one ridge on the inside of the pedunculate valve, pits in a diamond pattern on the inside of both valves, and without radial ridges that end in tubercles. It occurs in depths between 6 and 1300 m. It is known since the latest Cretaceous.

Botsfordioidea is a superfamily of Discinid brachiopods.

References

  1. Williams, A; Cusack, M; Buckman, J. O.; Stachel, T (1998). "Siliceous tablets in the larval shells of apatitic discinid brachiopods". Science. 279 (5359): 2094–6. PMID   9516107.