Research Article| April 01, 2007 THE ROTALIPORIDS, A POLYPHYLETIC GROUP OF ALBIAN-CENOMANIAN PLANKTONIC FORAMINIFERA: EMENDATION OF GENERA José María González-Donoso; José María González-Donoso 3 1Departamento de Ecología y Geología de la Universidad de Málaga, 27071 Málaga, Spain. 3Correspondence author. E-mail: jmgd@uma.es Search for other works by this author on: GSW Google Scholar Dolores Linares; Dolores Linares 1Departamento de Ecología y Geología de la Universidad de Málaga, 27071 Málaga, Spain. Search for other works by this author on: GSW Google Scholar Francis Robaszynski Francis Robaszynski 2Faculté Polytechnique, 9 rue de Houdain, 7000 Mons, Belgium. Search for other works by this author on: GSW Google Scholar Author and Article Information José María González-Donoso 3 1Departamento de Ecología y Geología de la Universidad de Málaga, 27071 Málaga, Spain. Dolores Linares 1Departamento de Ecología y Geología de la Universidad de Málaga, 27071 Málaga, Spain. Francis Robaszynski 2Faculté Polytechnique, 9 rue de Houdain, 7000 Mons, Belgium. 3Correspondence author. E-mail: jmgd@uma.es Publisher: Cushman Foundation for Foraminiferal Research Received: 09 Nov 2005 Accepted: 18 Dec 2006 First Online: 03 Mar 2017 Online ISSN: 1943-264X Print ISSN: 0096-1191 © 2007 Journal of Foraminiferal Research Journal of Foraminiferal Research (2007) 37 (2): 175–186. https://doi.org/10.2113/gsjfr.37.2.175 Article history Received: 09 Nov 2005 Accepted: 18 Dec 2006 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation José María González-Donoso, Dolores Linares, Francis Robaszynski; THE ROTALIPORIDS, A POLYPHYLETIC GROUP OF ALBIAN-CENOMANIAN PLANKTONIC FORAMINIFERA: EMENDATION OF GENERA. Journal of Foraminiferal Research 2007;; 37 (2): 175–186. doi: https://doi.org/10.2113/gsjfr.37.2.175 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyJournal of Foraminiferal Research Search Advanced Search Abstract The rotaliporids are a group of mid-Cretaceous planktonic foraminifera that have gained increasing stratigraphic importance in the last few decades. Six genera are presently described: Rotalipora, Thalmanninella, Anaticinella, Pseudoticinella, Pseudothalmanninella and Pseudorotalipora. All are identified on the basis of their morphological characters. Recent systematic studies of planktonic foraminifera have, however, highlighted the importance of an approach based on lineage affinities rather than simple morphological differences. Using this philosophy, we propose a revision of the rotaliporids according to their polyphyletic origin. In particular, we emend and redescribe the three genera Thalmanninella, Pseudothalmanninella and Rotalipora, including species previously attributed to Anaticinella, Pseudoticinella and Pseudorotalipora. We include Anaticinella (senior synonym of Pseudoticinella) in the genus Thalmanninella and Pseudorotalipora in Rotalipora. The retained genera are as follows.Pseudothalmanninella, which became extinct during the earliest Cenomanian, shows (a) a progressive development of a peripheral single keel and raised spiral sutures and (b) the development of periumbilical ridges and raised umbilical sutures.Thalmanninella, which became extinct in the latest Cenomanian, is characterized by progressive evolution (in several stages) that may be summarized as follows: (a) a progressive development of a peripheral single keel and spiral sutural ridges; (b) the appearance of periumbilical ridges and raised umbilical sutures on the umbilical side; and (c) the disappearance of these previously acquired characters in almost the reverse order during the final evolutionary stage. This includes the loss of umbilical sutural ridges followed by weakening and loss of the peripheral keel and spiral sutural ridges. This genus also shows a continuous variability in other features that are normally used for morphological definition of species: e.g., relative convexity of both sides, number of chambers, whorl expansion rate, shape of the equatorial periphery and other characters. This variability is the reason why, in the past, many species have been described and attributed to Thalmanninella.Rotalipora, which became extinct in the latest Cenomanian, shows (a) a progressive development of a peripheral single keel; (b) a development of raised spiral sutures; and (c) a development of a triradial ridge in the middle part of chambers on both the umbilical and dorsal sides. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.