Phylum Brachiopoda

Tree of Life
 

Phylum Brachiopoda

Kingdon Animalia

From the first dawn of life, all organic beings are found to resemble each other in descending degrees, so they can be classed in groups under groups. Charles Darwin, Origin of Species, Chapter 13


BrachiopodBrachiopods are marine organisms commonly called lamp shells that live on continental shelves and the upper parts of continental slopes. The soft parts of brachiopods are covered with a shell made of two valves that vary in size and chracteristics. The two valves are held together in two distinct ways that led to differentiation of brachiopods into two major groups: (1) In Articulate brachiopods, the valves are joined at the posterior end by means of teeth and sockets; and, (2) The Inarticulates, muscles join the two halves.

The brachiopods made their first unambiguous appearance in Early Cambrian, though Neoproterozoic forms are still ambiguous. Lingulids were the most common animals in Late Cambrian followed by Pentamerids. Ordovician brachiopods became Lingulella, an Ancient Brachiopod from Chengjiang Biotamore widespread in the Ordovician, as Orthids diversified into Strophomenids and Pentamenids into Rhynchonellids. Terebratulids appeared by the end of Silurian. Then began the phase of disappearance of Articulate brachipods. Many genera of Pentamerids, Strophomenids and Terebratulids disappeared in the Devonian.

Living brochiopodsAfter most brachiopods faced extinction in Permian, with only a few non-articulates, some Rhynchonellids, some Spiriferids and some Terebratulids continuing into the Mesozoic Era. Thereafter, brachiopods were represented only by Terebratulids and four non-articulate Orders.

The Brachiopods have left a prodigious and diverse fossil record. Compared with some 12,000 fossil species that are known, only 350 species exist today. Thus, they are much declined from their Paleozoic prominence, and yet the classification of these animals is a continuing challenge, requiring that modern genomics be used to unravel their evolutionary mysteries.

Phylum Brachiopoda Taxonomy
Subphylum
Class
Order
Extinct
Linguiliformea
Lingulata
Linguilida
no
Siphonotretida
Devonian
Acrotretida
Ordovician
Paterinata
Paterinida
no
Craniformea
Craniforma
Craniida
no
Craniopsida
Carboniferous
Trimerellida
Silurian
Rhychonelliformea
Chileata
Chileida
Cambrian
Dictyonellidina
Permian
Obolellata
Obolellida
Cambrian
Kutorginata
Kutorginida
Cambrian
Strophomenata
Orthotetidina
Permian
Triplesiidina
Silurian
Billingselloidea
Ordovician
Clitambonitidina
Ordivician
Strophomenida
Carboniferous
Productida
Permian
Rhynchonellata
Protorthida
Cambrian
Orthida
Carboniferous
Pentamerida
Devonian
Rhynchonellida
no
Atrypida
Devonian
Spiriferida
Jurassic
Thecideida no
Athyridida Cretaceous
Terebratulida no