TL;DR: The new calcisponges Regispongia fluegeli n.
Abstract: The new calcisponges Regispongia fluegeli n. sp., and Iranospongia circulara n. gen. n. sp., are described from central Iran. These are the first heteractinid sponges reported from the Permian of the region. These wewokellid sponges are large, irregularly cylindrical forms with a distinct axial spongocoel. The calcareous spicular skeletons of both taxa have been overgrown and are recrystallized. However, the preserved skeleton of Regispongia fluegeli does include large polyactines in the main endosomal layer and small octactines and possibly other polyactine spicules in both the relatively massive dermal layer and the distinct, delicately spiculed, gastral layer. Iranospongia is characterized by a discontinuous ring of vertical exhalant canals interior to the dense dermal layer, and by an interior skeleton net that includes common coarse vertical fibers. Individual spicules in Iranospongia are commonly obscured, but locally some remnants of possible polyactines occur in outer parts of the skeleton.
TL;DR: This work focuses on the diversity and evolution of sponge nutrition systems and the amazing adaptation to carnivory.
Abstract: Sponges are an ancient basal life form, so understanding their evolution is key to understanding all metazoan evolution. Sponges have very unusual feeding mechanisms, with an intricate network of progressively optimized filtration units: from the simple choanocyte lining of a central cavity, or spongocoel, to more complex chambers and canals. Furthermore, in a single evolutionary event, a group of sponges transitioned to carnivory. This major evolutionary transition involved replacing the filter-feeding apparatus with mobile phagocytic cells that migrate collectively towards the trapped prey. Here, we focus on the diversity and evolution of sponge nutrition systems and the amazing adaptation to carnivory.