Palaeos: Palaeos Linguliformea
Brachiopoda Siphonotretida


Siphonotretida

(Furongian-Ordovician)


Siphonotreta
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.






Brachiopod main page
Brachiopoda main page



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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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