Acanthocladiidae Zittel, 1880

Ernst, Andrej & Minwegen, Elke, 2006, Late Carboniferous bryozoans from La Hermida, Spain, Acta Palaeontologica Polonica 51 (3), pp. 569-588 : 582

Family Acanthocladiidae Zittel, 1880 Genus Penniretepora d'Orbigny, 1849

= Acanthopora Young and Young, 1875 ; = Pinnatopora Vine, 1883

Type species: Retepora pluma Phillips, 1836 , by original designation;

Lower Carboniferous, Ireland.

Diagnosis.—Fine main branch and short, regularly arranged secondary branches without dissepiments. Two rows of autozooecia on the main branch and on the secondary branches (translated after Morozova 2001).

Discussion.— Penniretepora is a polyphyletic taxon which generally includes Palaeozoic bryozoans with pinnate colony form and two rows of apertures on both the main and secondary branches. The following genera were also established on the basis of a pinnate colony form: Acanthocladia King, 1849 (three or more autozooecial rows on branches); Kalvariella Morozova, 1970 (two rows on the main branch and 3–4 rows on secondary branches) and Diploporaria Nickles and Bassler, 1900 (like Penniretepora but with rare secondary branches). This distinction is considered to be very artificial. Acanthocladia (sensu King 1849) has been revised quite recently ( Ernst 2001) and is apparently restricted to the Upper Permian Zechstein Basin. The monotypic genus Kalvariella is also known only from the Zechstein. Penniretepora and Diploporaria , as well as the remaining species assigned to Acanthocladia need to be revised using characters of the autozooecia and the presence or absence of heteromorphs.

Stratigraphic and geographic range.—Devonian to Permian; worldwide.