Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography Author Koromyslova, Anna V. 852422E7-8592-4209-AE5F-AD0554D11E7D Borissiak Paleontological Institute of the Russian Academy of Science, Profsoyuznaya st. 123, Moscow, 117997, Russian Federation. Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW 7 5 BD, UK. Senckenberg Forschungsinstitute und Naturmuseun, Sektion Marine Evertebraten III (Bryozoologie), Senckenberganlage 25, 60325 Frankfurt am Main, Germany. The Sedgwick Museum of Earth Sciences, Department of Earth Sciences, University of Cambridge, UK. koromyslova.anna@mail.ru Author Taylor, Paul D. 7AFF2929-DF5B-46B2-94E6-B26B396CC2C8 p.taylor@nhm.ac.uk Author Martha, Silviu O. C926B3E7-2C56-450E-9C81-B00793465CE0 silviu.martha@senckenberg.de Author Riley, Matthew 8E9D3DB4-6D14-4895-AD34-77C51022DA05 mlr44@cam.ac.uk text European Journal of Taxonomy 2018 2018-12-26 490 1 66 journal article 22081 10.5852/ejt.2018.490 52356089-4633-4477-99c9-45f18606f5b9 3830845 BE023137-CC5E-4DC5-94F6-B549BB140361 Key to species of Rhagasostoma described in this paper 1. Avicularia interzooidal, peripheral caverns usually present ............................................................. 2 – Avicularia vicarious, ovicells immersed, peripheral caverns lacking ............................................... 3 2. Avicularia longer than autozooids, ovicells endozooidal or immersed ............................................ 4 – Avicularia about ½ the autozooid size or less, ovicells endozooidal ................................................ 5 3. Opesia of autozooids with opesiular indentations ..................................... R. rowei ( Brydone, 1906 ) – Opesia of autozooids with opesiules ...................................................... R. mimosa ( Brydone, 1930 ) 4. Avicularian rostrum conical in outline, ovicells endozooidal ........................................................... 6 – Avicularian rostrum spade-shaped, ovicells immersed or not observed ........................................... 7 – Avicularian rostrum falciform, ovicells endozooidal ....................................................................... 8 5. Avicularian rostrum short and tilted to the right or left, gymnocyst present .................................... 9 – Avicularian rostrum long and straight, gymnocyst lacking ............ R. tchvanovi ( Favorskaya, 1992 ) 6. Avicularian rostrum asymmetrical .................................................................................................. 10 – Avicularian rostrum symmetrical .....................................................................................................11 7. Avicularian rostrum narrowed at the base, enlarged centrally and ended with top, ovicells immersed ............................................................................................................. R. brydonei sp. nov. – Avicularian rostrum almost the same width along the whole of its length and with pointed or rounded top, ovicells not observed ............................................................................. R. operculatum sp. nov. 8. Avicularian rostrum with one side of rostrum almost straight and other side curved near top .......... .................................................................................................................. R. minuens Brydone, 1936 9. Autozooidal cryptocyst with slightly convex border; gymnocyst very rarely observed .................... ............................................................................................................. R. gibbosum ( Marsson, 1887 ) – Autozooidal cryptocyst with convex border; gymnocyst well developed .......................................... ............................................................................................................. R. gibbosulum Brydone, 1936 10. Avicularian opesia large, roundish or oval with thickened distolateral edge and with thin articular ridges bearing two short teeth proximally and a short or long, slit-like opesiular indentation between the teeth; opesiules lacking ................................................................. R. inelegans ( Lonsdale, 1850 ) – Avicularian opesia distal, small, subcircular; two lateral parallel slit-like opesiules formed by long teeth of articular ridges and a long, slit-like opesiular indentation between the teeth proximally below opesia .............................................................................................. R. angliae Brydone, 1936 11. Avicularian opesia egg-shaped, with thin articular ridges bearing two short teeth proximally and a short or long slit-like opesiular indentation between the teeth; opesiules lacking ............................. ............................................................................................................................. R. aralense sp. nov.