Operculina and Neoassilina: A Revision of Recent Nummulitid Genera Based on Molecular and Morphological Data Reveals a New Genus

Abstract The genus Operculina , a large symbiont-bearing benthic foraminifer, is characterized by high morphological variability showing thick involute to intermediate semi-involute flat evolute tests. Different morphotypes are either considered as ecophenotypes or distinct species. In order test the hypothesis of versus different species, single cell throughput sequencing approach was applied assess interspecific diversity . This results in two groups ribotypes, one corresponding ammonoides / discoidalis other containing complanata elegans These can also be separated morphologically. Therefore, O. and represent species latter regarded junior synonym complanata. form which makes Because generic differences manifested morphology molecular genetics, Neoassilina with designated installed. Additional analysis ribosomal SSU rDNA data eight recent nummulitid genera confirms obtained troughput further shows that Palaeonummulites venosus builds clade branches at base Nummulitidae Planostegina Planoperculina Cycloclypeus Heterostegina Operculinella