Homotrypa Ulrich 1882

Genus Homotrypa Ulrich, 1882 TYPE SPECIES. — Homotrypa curvata Ulrich, 1882 by original designation. Cincinnatian, Upper Ordovician; North America. DIAGNOSIS. — Ramose and frondose colonies, often flattened, sometimes encrusting and irregularly massive in initial stages. Autozooecia with polygonal, rounded or oval apertures. Walls slightly thickened in exozone, integrate, diagonally and longitudinally laminated. Cystiphragms only in exozone, diaphragms commonly in exozone. Mesozooecia from rare to abundant, sometimes clustering in maculae. Acanthostyles abundant, commonly small. OCCURRENCE. — Middle Ordovician to Lower Silurian; North America, Europe, Australia, Siberia. COMPARISON The genus Homotrypa Ulrich, 1882 differs from the genus Monticulipora d’Orbigny, 1850 by its branched erect colony instead of the encrusting or massive one in Monticulipora. Furthermore, cystiphragms in Homotrypa are usually concentrated in the inner exozone, whereas cystiphragms in Monticulipora occur throughout autozooecial chambers.
Published as part of Ernst, Andrej & Carrera, Marcelo G., 2022, A cool-water bryozoan association from the La Pola Formation (Sandbian, Ordovician) of Argentine Precordillera, pp. 563-601 in Geodiversitas 44 (20) on page 572, DOI: 10.5252/geodiversitas2022v44a20, http://zenodo.org/record/6725916
{"references":["ULRICH E. O. 1882. - American Palaeozoic Bryozoa. The Journal of the Cincinnati Society of Natural History 5: 121 - 175, 233 - 257."]}