Brachiopoda Siphonotretida



Siphonotreta tertis (Walcott)
a, brachial and b pedicle valves
length about 5 mm
Furongian, Alberta.
image from Moore, Lalicker and Fischer, Invertebrate Fossils, McGraw-Hill Book Company Inc, 1952, p.224

The siphonotretids are another one of the many small early lineages of inarticulate brachiopods. Both valves typically have obtuse-angle interareas and marginal apices. The pedicle opening is apical or in front of the apex of the pedicle valve (see above, right)

Characters: "Primitive thick-walled calcareous or chitinous shells with the pedicle emerging through a ventral sheath. The pedicle opening is circular, tends to be axial, and is not modified by a listrium. It may be posterior or anterior to the protegulum and may be elongate if it has migrated through the protegulum." - Twenhofel, W. H., and Shrock, R. R., Invertebrate Paleontology, 1935. McGraw- Hill Book Co., N. Y. p.287 (copyright expired)

Life posture of Schizambon. The pedicle opening is located between the apex of the pedicle valve and the shell margin.

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page uploaded 7 June 2002
checked ATW021217
(originally uploaded on Kheper site uploaded 15 May 1999)
page by M. Alan Kazlev (Creative Commons Attribution license) 1999-2002
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