Tobolocella levinae n. gen., n. sp., a cheilostome bryozoan from the late Maastrichtian of northern Kazakhstan: scanning electronmicroscope and micro-CT study

A cheilostome bryozoan Tobolocella levinae gen. et sp. nov. is described from a late Maastrichtian outcrop located on the right bank of the Tobol River in northern Kazakhstan. Its morphology is investigated in detail using combined scanning electron microscopy and X-ray micro-CT data. These studies reveal that colonies of this new genus generally consist of regularly arranged but morphologically different zooids: autozooids, T-zooids, and vicarious avicularia. The T-zooids first established in T. levinae gen. et sp. nov. are zooids with a modified cystid and can be interpreted as autozooidal polymorphs, if its polypide was identical to that of regular autozooids, or heterozooids, if its polypide was modified. The T-zooids probably can increase the distance between autozooidal polypides to improve their feeding efficiency.