Trepostomata

Heterotrypa frondosa, from Digital Atlas of Ordovician Life.

Belongs within: Cystoporata.

The Trepostomata are a group of bryozoans known from the Ordovician to the Triassic, being particularly abundant during the Ordovician. Massive trepostome colonies form a dominant component of some Ordovician limestones (Prothero 1998).

Characters (from Prothero 1998): Zoarium including three different forms of zooecia: autopores, with large diameter, rounded cross section, short horizontal dividing walls (diaphragms); mesopores located adjacent to autopores, with smaller diameter, more angular cross section, many diaphragms; acanthopores located at junctions between two or more autopores or mesopores, tiny, thick-walled, supporting a small spine.

<==Trepostomata
    |  i. s.: Annuhziopora Vinassa 1920 PP05
    |           `--A. foordi (Nicholson 1879) PP05
    |         Batostoma cornula PP05
    |         Prasopora conoidea P98
    |         Dekayella praenuntia P98
    |         *Monotrypella aequalis SG-M98
    |--Esthonioporina P98
    |    |--Esthonioporidae PP05
    |    `--Dianulites [Dianulitidae] PP05
    |         `--D. petropolitanus PP05 [=Monticulipora petropolitana R66]
    `--+--Amplexoporina P98
       `--Halloporina P98
            |  i. s.: Hallopora H75
            |           `--‘Oldhamia’ pedemontana H75
            |--Mesotrypidae PP05
            |--Hexaporites Pander 1830 [Halloporidae] PP05
            |    `--*H. fungiformis Eichwald 1860 (see below for synonymy) PP05
            `--Heterotrypidae PP05
                 |--Eichwaldopora Pushkin & Popov 2005 PP05
                 |    `--*E. ovulum Pushkin & Popov 2005 [=Monticulipora ovulum] PP05
                 `--Heterotrypa EB03
                      |--H. frondosa EB03
                      `--H. humensis Ross 1961 F71

*Hexaporites fungiformis Eichwald 1860 [=Dianulites petropolitanus var. hexaporites Dybowski 1877, H. hexaporites] PP05

*Type species of generic name indicated

REFERENCES

[EB03] Erickson, J. M., & T. D. Bouchard. 2003. Description and interpretation of Sanctum laurentiensis, new ichnogenus and ichnospecies, a domichnium mined into Late Ordovician (Cincinnatian) ramose bryozoan colonies. Journal of Paleontology 77 (5): 1002–1010.

[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1–167.

[H75] Häntzschel, W. 1975. Treatise on Invertebrate Paleontology pt W. Miscellanea. Suppl. 1. Trace Fossils and Problematica 2^nd ed. The Geological Society of America: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[P98] Prothero, D. R. 1998. Bringing Fossils to Life: An introduction to paleobiology. WCB McGraw-Hill: Boston.

[PP05] Pushkin, V. I., & L. E. Popov. 2005. Two enigmatic bryozoans from the Middle Ordovician of the East Baltic. Palaeontology 48 (5): 1065–1074.

[R66] Regnéll, G. 1966. Edrioasteroids. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 1 pp. U136–U173. The Geological Society of America, Inc., and The University of Kansas Press.

[SG-M98] Schäfer, P., & J. A. Grant-Mackie. 1998. Revised systematics and palaeobiogeography of some Late Triassic colonial invertebrates from the Pacific region. Alcheringa 22 (2): 87–122.