Terebratulida
Encyclopedia
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".
Terebratulids typically have biconvex shells that are usually ovoid to circular in outline. They can be either smooth or have radial ribbing. The lophophore
support is loop shaped in contrast to the spiralia of similar looking spiriferids. Terebratulids are also distinguished by a very short hinge line, and the shell is punctate in microstructure. There is a circular pedicle
opening, or foramen
, located in the beak.
Terebratulids may have evolved from Atrypids during the early or Middle Silurian
. Early genera were almost circular to elongate-oval, with smooth or finely costate shells. During the Cretaceous
and Tertiary
periods, many shells became coarsely plicate.
Extinct Superfamilies
Rhynchonellida
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....
and the Thecideida
Thecideida
Thecideida is an order of cryptic articulate brachiopods characterized by their small size and habit of cementing their ventral valves to hard substrates such as shells, rocks and carbonate hardgrounds...
. Craniida and Lingulida
Lingulida
Lingulida is an order of brachiopods....
include living brachiopods, but are inarticulates
Inarticulata
Inarticulata was historically defined as one of the two classes of the phylum Brachiopoda and referred to those having no hinge. The other class was Articulata, meaning articulated – having a hinge between the dorsal and ventral valves...
. 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".
Terebratulids typically have biconvex shells that are usually ovoid to circular in outline. They can be either smooth or have radial ribbing. The lophophore
Lophophore
The lophophore is a characteristic feeding organ possessed by four major groups of animals: the Brachiopoda, Bryozoa, Entoprocta, and Phoronida. All lophophores are found in aquatic organisms.-Characteristics:...
support is loop shaped in contrast to the spiralia of similar looking spiriferids. Terebratulids are also distinguished by a very short hinge line, and the shell is punctate in microstructure. There is a circular pedicle
Pedicle (zoology)
In zoology, the pedicle refers to a fleshy line brachiopods and some bivalve mollusks use to attach and anchor to a substrate. In brachiopods, the pedicle emerges from a pedicle opening. Some brachiopods do not have a functional pedicle, and thus do not have this pedicle opening....
opening, or foramen
Foramen
In anatomy, a foramen is any opening. Foramina inside the body of humans and other animals typically allow muscles, nerves, arteries, veins, or other structures to connect one part of the body with another.-Skull:...
, located in the beak.
Terebratulids may have evolved from Atrypids during the early or Middle Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
. Early genera were almost circular to elongate-oval, with smooth or finely costate shells. During the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
and Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
periods, many shells became coarsely plicate.
Classification
- Suborder TerebratellidinaTerebratellidinaTerebratellidina is one of two existing suborders of Terebratulid brachiopods, the other being Terebratulidina.- Classification :* Superfamily Kraussinoidea* Superfamily Laqueoidea* Superfamily Megathyridoidea* Superfamily Platidioidea...
- Superfamily Kraussinoidea
- Superfamily Laqueoidea
- Superfamily Megathyridoidea
- Superfamily Platidioidea
- Superfamily Terebratelloidea
- Family Dallinidae
- Family Ecnomiosidae
- Family Terebratellidae
- Family Thaumatosiidae
- Superfamily Zeillerioidea
- Superfamily Bouchardioidea
- Superfamily Gwynioidea
- Superfamily Kingenoidea
- Superfamily Incertae sedisIncertae sedis, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
- Family Tythothyrididae
- Suborder Terebratulidina
- Superfamily Cancellothyroidea
- Family Cancellothyrididae
- Family Chlidonophoridae
- Family Cnismatocentridae
- Superfamily Dyscoloidea
- Superfamily Terebratuloidea
- Family Gryphidae
- Family Tichosidae
- Family Terebratulidae
- Superfamily Cancellothyroidea
Extinct Superfamilies
-
- Superfamily Dielasmatoidea †
- Superfamily Cryptonelloidea †
- Superfamily Loboidothyridoidea †
- Superfamily Stryingocephaloidea †