Heterotrypa frondosa, from Digital Atlas of Ordovician Life.

Belongs within: Stenolaemata.
Contains: Trematoporidae, Dyscritellidae, Stenoporidae, Ulrichotrypellidae, Cystoporata, Cryptostomata, Halloporina.

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.

    |  `--+--CryptostomataTE04
    |     `--+--HalloporinaTE04
    |        `--MonotrypaT93 [Amplexoporidae, AmplexoporinaTE04]
    |             |--M. helenae Modzalevskaya 1953T93
    |             |--M. hsui Yang 1950T93
    |             |--M. macroporaO69
    |             `--M. paterella Owen 1969 [=M. patera Owen 1962 non M. (Dianulites) patera Vinassa de Regni 1911]O69
         |--EsthonioporaT93 [EsthonioporidaePP05]
         |    |--E. lessnikovae (Modzalevskaya 1953)T93
         |    `--E. subsphaerica (Bassler 1911)T93
         `--Dianulites [Dianulitidae]PP05
              |--D. fastigiatus Eichwald 1829T93
              |--D. glauconiticus Mannil 1959T93
              |--D. globularis Bassler 1928T93
              |--D. janishewskyi Modzalevskaya 1953T93
              |--D. multimesoporicus Modzalevskaya 1953T93
              `--D. petropolitana Dybowski 1877T93 [=Monticulipora petropolitanaR66]
Trepostomata incertae sedis:
  Annuhziopora Vinassa 1920PP05
    `--A. foordi (Nicholson 1879)PP05
  Batostoma cornulaPP05
    |--Homotrypa instabilis Ulrich 1886T93
         |--P. conoideaP98
         `--P. gotlandica Hennig 1908T93
  Dekayella praenuntiaP98
    |--*M. aequalisSG-M98
    |--M. benthallensisO69
    `--M. pulchellaO69
    |--Atactotoechus typicusBS12
    |--Cyphotrypa antiqua (Modzalevskaya 1953)T93
    |--Permopora kapitzai Romanchuk 1967T93
    `--Neoeridotrypella pulchra Morozova 1970T93
    |--Orbipora crassaG31
         |--C. densus Duncan 1939T93
         |--C. granosus Duncan 1939T93
         `--C. petoskeyensis Duncan 1939T93
    |    |--H. imperfectum (Ulrich 1890)T93
    |    `--H. whitfieldi (James 1875)T93
         |--D. annulata (Eichwald 1860)T93
         |--D. clavaeformis Dybowski 1877T93
         |--D. ramosa Modzalevskaya 1953T93
         `--D. sokolovi Modzalevskaya 1953T93
    |--Champlainopora chazyensis (Ross 1963)T93
    `--Bimuropora winchelli (Ulrich 1886)T93
  Eostenopora [Stereotoechidae]T93
    |--E. peculiaris (Bassler 1906)T93
    `--E. tumida (Girty 1911)T93
    |--Anisotrypa proavus Astrova 1970T93
    `--Anisotrypella borealis Morozova 1967T93
    |--Callocladia kaugatumensis Astrova 1970T93
    `--Tabuliporella permiana Baranova 1960T93
    |--Aisenvergia cylindrica Dunaeva 1964T93
    |--Volnovachia distincta Dunaeva 1964T93
         |--P. asphinctus Boardman 1960T93
         |--P. clausus Boardman 1960T93
         `--P. devonicus (Ulrich 1890)T93
  Nippostenopora [Nippostenoporidae]T93
    |--N. elegantula Sakagami 1960T93
    `--N. tabulata Dunaeva 1963T93
  Araxopora [Araxoporidae]T93
    |--A. araxensis (Nikiforova 1933)T93
    |--A. bifoliata Morozova 1965T93
    |--A. macrocava Morozova 1965T93
    |--A. minax (Morozova 1970)T93
    |--A. spinata Morozova 1965T93
    `--A. variana (Yang 1958)T93
  Helenopora [Helenoporidae]T93
    `--H. duncanae Ross 1988T93
  Astralochoma [Astralocomidae]T93
    `--A. helenae Ross 1988T93
    |--C. cylindrocellulaiaY92
    |--C. repensC01
    `--C. sparsaC01
    |--G. chinensisG31
    |--G. columnaris (see below for synonymy)G31
    `--G. crassaG31
  Batostomella Ulrich 1882 [Batostomellidae]O69
    |--B. cylindrica Crockford 1941F71
    |--B. granuliferaO69
    |--B. lineata Crockford 1947F71
    `--B. maniformis Owen 1869O69

Geinitzella columnaris [=Stenopora columnaris; incl. S. collunnaris var. camosa, S. collunnaris var. multigemmata, Geinitzella columnaris var. ramosasparsigemmata, G. columnaris var. tuberosa, G. columnaris var. tuberosasparsigemmata Grabau 1931]G31

*Type species of generic name indicated


[BS12] Brett, C. E., T. Smrecak, K. P. Hubbard & S. Walker. 2012. Marine sclerobiofacies: encrusting and endolithic communities on shells through time and space. In: Talent, J. A. (ed.) Earth and Life: Global biodiversity, extinction intervals and biogeographic perturbations through time pp. 129–157. Springer.

[C01] Chapman, F. 1901. On some fossils of Wenlock age from Mulde, near Klinteberg, Gotland; with notes by Prof. T. Rupert Jones and Dr. F. A. Bather. Annals and Magazine of Natural History, series 7, 7: 141–160, pl. 3.

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

[G31] Grabau, A. W. 1931. The Permian of Mongolia: A report on the Permian fauna of the Jisu Honguer limestone of Mongolia and its relations to the Permian of other parts of the world. American Museum of Natural History: New York.

[O69] Owen, D. E. 1969. Wenlockian Bryozoa from Dudley, Niagara and Gotland and their palaeogeographic implications. Palaeontology 12 (4): 621–636.

[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.

[T93] Taylor, P. D. 1993. Bryozoa. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 465–489. Chapman & Hall: London.

[TE04] Taylor, P. D., & A. Ernst. 2004. Bryozoans. In: Webby, B. D., F. Paris, M. L. Droser & I. G. Percival (eds) The Great Ordovician Biodiversification Event pp. 147–156. Columbia University Press.

[Y92] Yu W. 1992. On the occurrence of Spirina in China. Wuyi Science Journal 9: 283–285.

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