ACTA PALAEONTOLOGICA ROMANIAE V. 4 (2004), P. 403-421 CONTRIBUTIONS TO THE KNOWLEDGE OF THE CALCAREOUS UNICAMERAL FORAMINIFERA FROM THE MIDDLE MIOCENE OF ROMANIA 1 2 GHEORGHE POPESCU & ILEANA-MONICA CRIHAN Abstract. This paper deals with a very diversified group of foraminifera, systematically considered to belong to more suprageneric taxa of the order Lagenida. They are revised according to the newly published nomenclature in the recent literature. We accept here the subdivision of the unilocular foraminifera into two families made by Loeblich & Tappan (1988): family Lagenidae, with the genera Hyalinonetrion Patt. & Rich., Lagena Walker & Jacob, Obliquina Seg., Procerolagena Puri, Pymaeoseistron Patt. & Rich., Reussoolina Colom, Rimulinoides Saidova and Tetragonulina Seg., and the family Ellipsolagenidae, with 4 subfamilies (Oolininae, Ellipsolageninae, Parafissurininae, Sipholageninae). A new genus (Fissurinella) is proposed, as well as five new species (Fissurina buchneri, Cursina porocostata, Paliolatella grossecarinata, Parafissurina spinulata and Geminiella caudata). Keywords: Unicameral foraminifera, Middle Miocene, Romania INTRODUCTION • Family Lagenidae with the genera The two families of foraminifera which make the Hyalinonetrion PATTERSON & RICHARDSON, subject of this paper include single chambered 1987, Lagena WALKER & JACOB, 1798, Obliquina species (unicameral). SEGUENZA, 1862, Procerolagena PURI 1954, Most of the Badenian unicameral foraminifera Pymaeoseistron PATTERSON & RICHARDSON, come from pelitic deposits accumulated in 1987, Reussoolina COLOM, 1956, Rimulinoides sedimentary basins with depths greater than 200 m, SAIDOVA, 1975 and Tetragonulina SEGUENZA, in outer neritic or bathial facies. The richest samples 1862. Characteristic for these genera is the in foraminifera from this group were colected from unilocular test and the circular terminal aperture, outcrops on the western border of the Pannonian which can also be at the end of a neck. Depression and Transylvania (for the Lower • Family Ellipsolagenidae which includes Badenian = Langhian) and from western Oltenia, monothalamous foraminifera whose aperture is Getic Depression and the Subcarpathians of prolonged with a tube in the interior of the chamber Muntenia (for the Middle-Upper Badenian = Lower (entosolen). Serravallian). The following subfamilies were separated here: THE GROUP OF THE UNICAMERAL FORAMINIFERA • Oolininae, with radially symmetric test, Diagnosis. Test unilocular, wall calcareous, aperture circular or radial, with entosolen. Here were optically radial, sometimes two layered; aperture included the genera Anturina JONES, 1984, terminal or subterminal, circular, ovate or elongated, Buchnerina JONES, 1984, Cushmanina JONES, pseudoradial or trematophore with or without 1984, Exculptina PATTERSON & RICHARDSON, entosiphon; aboral opening circular, elliptical or slit- 1987, Favulina PATTERSON & RICHARDSON, like. 1987, Galwayella PATTERSON & RICHARDSON, Remarks. In a previous paper (Popescu, 1983), 1987, Heteromorphina JONES, 1984, Homalohedra most of the unilocular foraminifera were grouped PATTERSON & RICHARDSON, 1987, Laculatina within the family Lagenidae. Two morphological PATTERSON & RICHARDSON, 1987, Oolina features were considered: (1) the unilocular test and D'ORBIGNY, 1839, Pristinosceptrela PATTERSON (2) the presence of the aboral opening. The last & RICHARDSON, 1987, Vasicostella PATTERSON feature of the family Lagenidae was neglected by & RICHARDSON, 1987. other authors. The aboral opening was considered • Elipsolageninae, with elongated slit-like there as an important morphological element at aperture, bilaterally symmetric (Duplella suprageneric or generic level. PATTERSON & RICHARDSON, 1987, Fissurina Jones (1984) distinguished at least 9 evolutive REUSS, 1862, Lagenosolenia MCCULLOCH, 1977, lineages from which the unicameral foraminifera Lagnea POPESCU, 1983, Paliolatella PATTERSON could have emerged, thus underlining the & RICHARDSON, 1987, Pseudoolina JONES, 1984). polyphyletic character of the group. Loeblich & Tappan (1988) included this group into • Parafissurininae, with subterminal two families: asymmetric aperture and entosolenian tube (Cursina PATTERSON & RICHARDSON, 1987, Irenita 1 Geological Institute of Romania, Caransebes St. 1, 78344-Bucuresti, Romania 2 University Petroleum and Gas, Bd. Bucuresti 39, 2000 Ploiesti, Romania 403 G. POPESCU & I.M. CRIHAN JONES, 1984, Parafissurina PARR, 1947, height of the chamber) as in Lagnea, long rectilinear Pseudosolenina JONES, 1984, Ventrostoma (Cribrolagena), curved toward the dorsal wall SCHNITKER, 1970, Walterparria JONES, 1984, (Fissurina partim.) or torsioned (Fissurina pretiosa). Wiesnerina JONES, 1984). The aboral opening varies from a circular aspect • Sipholageninae, with two layered wall to elliptical to an elongated slit, and in the more (Bifarilamella PATTERSON & RICHARDSON, 1987, evolved genera as a fissure, sometimes completely Pytine MONCHARMONT ZEI & SGARELLA, 1978, closed, its presence being noticeable only in optical Sipholagena MONCHARMONT ZEI & SGARELLA, sections as an opacque spot in the aboral-ecuatorial 1978). zone. The previously mentioned calssification will be Sometimes, the aboral opening is at the end of a also followed in the present paper. tube crossing the wall (in genus Hyalinonetrion or in The problem of the evolution of the the species Lagena micans BUCHNER, 1940). The monothalmous foraminifera was for the first time function of this opening is not clear. Due to the fact debated by Parr (1947) who suggested, being the that sometimes it is "knited" to the test might lead to succesive appearance of the genera Lagena, Oolina, the assuption that it represents a part of the apertural Fissurina and Parafissurina, the existence of some neck of the "mother" specimen, which remained after phyletic relationships (the genus Lagena at the basis the reproduction (budding type reproduction). In this of the evolution of the other three genera). case the presence of the aboral opening could be Other characters as the shape and position of the related only to the reproduction process. aperture, shape of the test, ornamentation, shape Other important morphological features (genetic and position of the inner tube (entosolen/entosiphon) and specific) are the test structure and surface, the are considered as generic or specific, or rarely, shape of the latero-frontal projection (circular, suprageneric characters. elliptical, ovate, elongated, fusiform, trucated), the We will discuss next some of the morphological shape of the test (spherical, lenticular, ellipsoidal), characters and their taxonomic importance. and finally ornamentation. This last character can The aperture of the unicameral foraminifera vary sometimes within the same species according evolved from a circular or elliptical opening, with or to the environmental conditions. without an apertural lip to an elongated opening, SISTEMATIC DESCRIPTIONS symmetric slit-like, in ecuatorial plan or asymmetric. The presence of the radial or trematophore apertures Order LAGENINA is an indication that those species could emerge Superfamily Nodosariacea EHRENBERG, 1838 from different phyletic lineages. Circular apertures Family Lagenidae REUSS, 1862 with or without a lip are characteristic for the less Hyalinonetrion PATTERSON & RICHARDSON, evolved species (Lagena, "Phialinea", Oolina, 1987 Cushmanina). The aperture evolved to elliptical shape (as in Lagnea), and then elongated or slit-like, Monothalamous test, elongated to fusiform; wall in terminal position, in ecuatorial plane axe and calcareous hyaline, surface smooth, unornamented; symmetric reported to the axe (Fissurina, aperture circular, at the end of an elongated neck, Lagenosolenia). The radial and cribrate types of bordered by a reverted phialine lip; aboral opening aperture are rare. The species with this type of as a tube which can be continued inside the aperture cannot be included in the proposed chamber. taxonomical classifications due to their ancestry. Entosiphon, or inner tube, or entosolenian Hyalinonetrion clavatum (D'ORBIGNY, 1846) tube, distinctive morphological element at the (Pl. 1, figs. 1-5) suprageneric, generic or specific level, appears in Oolina clavata d'Orbigny, 1846, p. 24, pl. 1, fig. 2, 3. Lagena clavata (d'Orbigny). Papp & Schmid, 1985, p. 21, certain groups of monothalamous which could have pl. 1, figs. 6-9; Popescu, 1982, p. 262, pl. 1, figs. 13, different evolutionary lineages. The inner tubes are 14. present in numerous foraminiferal families as Test fusiform, prolonged; surface smooth, buliminids, bolivinids, pleurostomellids, uvigerinids unornamented; aperture terminal, at the end of a etc. narrowing neck; aboral opening present. The fact that the inner tube was recorded at Range: Badenian. species with terminal, circular (e. g. Favulina hexagona [WILLIAMSON, 1848]), elliptical (Lagnea, Lagena WALKER & JAKOB, 1798 Pseudosolenia), slit-like (Fissurina) or subterminal (Parafissurina) aperture is an indication that the Test unilocular, globular or subovate; wall unicameral foraminifera are polyphyletic, therefore calcareous, hyaline, ornamanted with spines, costae they cannot be grouped into a single family. or longitudinal striae; aperture circular, terminal, The shape of the inner tube can be straight and sometimes at the end of a coleret with or without a short (Favulina), rectilinear average sized (1/2 of the 404 CONTRIBUTIONS TO THE KNOWLEDGE OF THE CALCAREOUS UNICAMERAL FORAMINIFERA FROM THE MIDDLE MIOCENE