The study of upper Eocene-Oligocene larger foraminiferal assemblages in two sections of the Prebetic Range in south-eastern Iberia (Ibi and La Font Roja sections) revealed a rich diversity, including species previously known only from the Central Tethys, such as the Eocene Neorhipidionina cf. spiralis, and the Oligocene Pfendericonus globulus, Austrotrillina howchini, Idalina pignattii, and Archaias sp., as well as endemic forms such as Peneroplis peramplus, Spirolinella emmae, and Borelis sp. 1. The continuous record of Austrotrillina (Rupelian-Chattian) and Risananeiza (upper Chattian) showed evolutionary trends and allowed for a systematic revision. Austrotrillina asmariensis, A. striata, and A. brunni are considered morphotypes of a single species, A. striata, evolving anagenetically from the lower Rupelian A. paucialveolata, which originated from the Eocene A. eocaenica. The two known species of Risananeiza, R. crassaparies and R. pustulosa, were identified for the first time within the same stratigraphic section. They represent successive stages of an anagenetic species throughout the upper Chattian. The biostratigraphic results provide an improved characterization of Shallow Benthic zones SB 21 to 23 in the westernmost Tethys and allow the subdivision of SB 23 (upper Chattian) into two sub-biozones, 23A and 23B, based on the stratigraphic ranges of miogypsinids (Miogypsinella spp., Postmiogypsinella intermedia) and Risananeiza. The Priabonian-Chattian Neorotalia burdigalensis also exhibits evolutionary trends with potential biostratigraphic relevance. Overall, the biostratigraphic data obtained indicate diachronous, parallel evolution and extinction in several genera, improving our understanding of diversity patterns and migration pathways in Oligocene larger Foraminifera.
Over 3.5 km south of Roaix village, the middle Ouvèze riverbed has undergone an incision of 5-9 m into its substratum since 1995. The local nesting of the river and erosion of its banks reveals a more complex geometry of exposed Pliocene deposits than previously recognised. The Pliocene stratigraphic succession includes, at the base of the classical Blue Marls, a prograding-aggrading stack of more or less nested, sigmoidal sandstone-marlstone cycles, each comprising an erosive sandstone wedge followed by a draping aggrading marlstone. Sedimentary features suggest that the main depositional mechanism for sandstone was high-velocity hyperpycnal bottom currents linked to river floods updip. These findings are presented in the context of the ria network of the Middle Rhône valley, including mostly unpublished data from the Andra (French Agency for Nuclear Waste Disposal) exploratory works in the lower Cèze valley in the 1990s. The combined data fail to support the idea of a so-called ”Zanclean Deluge” during the reflooding of the Mediterranean basin after the Messinian salinity crisis.
This study provides the first record of the genus Anoxypristis in Romania and in the whole of southeastern Europe based on two isolated rostral spines discovered in Priabonian deposits of the Transylvanian Basin. Assessment of the validity of previously described Paleogene species of Pristidae emphasizes the need for more rigorous taxonomic criteria based on more than isolated rostral spines. The paleoecological implications of the Romanian Anoxypristis specimens, considering the habitat preferences of the extant species and the depositional environments represented by the fossiliferous strata, point to a coastal or estuarine setting.
Upper Barremian-lower Aptian Urgonian-type platform carbonates from Ardèche yield a rich rudist fauna belonging to the families Requieniidae, Monopleuridae, Caprinidae, and Polyconitidae. The upper Barremian assemblage from the Ardèche river gorges consists of eighteen species, it conforms to the Rustrel fauna of the Monts-de-Vaucluse but contains a new genus Valclusella, and a new species of Bicornucopina, a genus unknown so far in Western Europe, whereas Mathesia darderi is identified for the first time in SE France. We define the "Saint-Montan limestones", of early Aptian age, as the uppermost member of the Urgonian Formation in this region. The corresponding Saint-Montan fauna is described for the first time: it contains twenty-five rudist species, of which eight are new and seventeen are inherited from the antecedent late Barremian Orgon and Rustrel fossil type localities. Of the eight new species, two are ascribed to earlier genera, i.e., Homopleura parva and Bicornucopina acuminata, three are assigned to a new genus, Myostyla ardescensis, while Valclusella valclusensis and Valclusella biconvexa preexisted in the late Barremian. Aside from inherited taxa, e.g., Pachytraga paradoxa, Praecaprina varians-gaudryi, Caprina douvillei, important novelties regard the Caprinidae, characterized by the appearance of probable new species of Pachytraga, P. aff. paradoxa, Offneria, O. aff. rhodanica, and three new species of Praecaprina: Pr. tubifera n. sp., Pr. paquieri n. sp., and Pr. vacua n. sp. The early Aptian p.p., therefore, coincides with the acme of the genus Praecaprina, SE France being unique in this respect. In the Saint-Montan fauna, up to about nine species from the Rustrel fauna are missing. The Saint-Montan rudist assemblage is unique, thus far, in SE France, even as the study of its composition is still in progress. It has a West European character, similar to that of its antecedent late Barremian one, and the succeeding late early Aptian Villaroya de los Pinares fauna from Spain, but the three have distinctive taxonomic compositions. The Saint-Montan stratigraphic succession is framed by two drowning boundary events. The taxonomic composition of its rudist assemblage fills a gap between the late Barremian and the late early Aptian faunas, and represents a distinctive episode in the Barremian-lower Aptian Urgonian-type rudist sequence of southern France and Spain, and possesses a significant biostratigraphic potential.
The SW-NE-trending Faucon-du-Caire/Turriers tectonic corridor hosts a thick Paleogene Molasse Rouge s.l. succession that shows similarities to the same interval found in the nearby Esparron syncline. In each setting, the succession is composed of three superposed sequences designated S1, S2 and S3 from bottom to top respectively (Ferry et al., 2025). Although similar in internal character, they vary in thickness between the two localities with respect to both complete sequences and subunits. Sequence S1 represents the western shore of a continental basin oriented to the Alpine Mountain Belt. Deposits of sequence S2 (Molasse Rouge 1, or MR1) are confined to a valley that forms a westward continuation of the Esparron syncline, terminating against the Grand Vallon fault, which caused a shift of the river to the southwest where its exits the Digne transported basin. Downstream, its course likely followed the front of the Ventoux-Lure thrust. Deposits of sequence S3 (Molasse Rouge 2, or MR2) are up to 500 m thick in the Faucon-du-Caire/Turriers area, comprising a lower pebbly facies, around 200 m thick, that was formed by a braided fluvial system. This is overlain by reddish sandstone-dominated alluvial fan deposits approximately 300 m thick. Sequence S3 appears to be mostly constrained to the Faucon-Turriers corridor. Its materials were transported to the SW, exiting the Digne nappe along the front of the Ventoux-Lure thrust. This path is better documented than that of MR1. A first major point is confirmation that a major change in paleocurrent orientation occurred around the Rupelian-Chattian transition, with the deposits of upper Rupelian sequence S1 being oriented to the Alps, and those of the Chattian sequences S2 and S3 oriented the opposite direction to the west. A second point is that strong tectonic deformation occurred between the deposition of MR1 and MR2.
Fourteen miogypsinid populations (ground-down free specimens, thin sections, and polished slabs) from Jamaica are analysed using univariate and bivariate statistics. The populations consist of one sample of free specimens from which orientated equatorial sections were prepared and thirteen populations with random equatorial sections on polished blocks. The populations are sorted into chronospecies based on mean X (Xm) values with four chronospecies (Miogypsinoides complanatus, Miogypsina thalmanni, Mio. 'basraensis', and Mio. tani) identified. Three samples collected from a single traverse show a succession of three successive chornospecies (Ms. complanatus, Mio. thalmanni, and Mio. 'basraensis'). Ms. complanatus is calibrated to around the Rupelian/Chattian boundary (based on data from Antigua), whereas advanced forms of Mio. tani are calibrated with the latest Chattian (based on planktic foraminifers, calcareous nannofossils, and Sr isotopes). The zonation for the Chattian using Larger Benthic Foraminifers is revised and five zones based on miogypsininids are recognized. This zonation enables the unconformity between the Moneague Formation (Rupelian to mid Chattian) and Newport Formation (latest Chattian) in Jamaica to be quantified. Comparison between the Americas and the Neotethys/Indo-Pacific indicates that miogypsinid evolution in the Chattian was more rapid in the Americas and that by the base of the Miocene, American miogypsinids were two chronospecies more advanced compared with their allies in the Neotethys/Indo-Pacific. This demonstrates that high resolution scanning of polished slabs represents a valuable tool for biostratigraphy of Larger Benthic Foraminifers.
The Biskoupky locality represents a tectonically delimited relict of Miaolingian sediments within Furongian volcanic rocks of the K & rcaron;ivokl & aacute;t-Rokycany Volcanic Complex, serving as the southernmost outcrop of the Miaolingian Buchava Formation of the Skryje-T & yacute;& rcaron;ovice Basin. Over a century of research focused on this outcrop has produced a well-documented assemblage of comparatively rare remains of skeletal fauna, including species so far restricted to this locality; however, a microfossil analysis has until now never been conducted. Herein, we present the results of a palynological analysis of material from samples of fine-grained siltstone to shale from the Biskoupky locality. The samples yielded moderately well preserved organic-walled microfossils, particularly the acritarch genera Cristallinium, Eliasum, Heliosphaeridium, Retisphaeridium, Solisphaeridium, Synsphaeridium, and multiple species of Timofeevia. For the first time in the Skryje-T & yacute;& rcaron;ovice Basin, the presence of Adara? sp. is documented. The presence of Timofeevia here and in previously recorded acritarch assemblages from the Skryje-T & yacute;& rcaron;ovice Basin suggests a later-than-expected deposition of the Buchava Formation.
This study examines the texture and reworked planktonic Foraminifera present in dredged and non-dredged sediments from the Guadalquivir Estuary (SW Spain). Dredging significantly changes the grain size of natural silty-clay sediments to fine silty sands in dredged areas. The density and diversity of planktonic Foraminifera, which originate from Cretaceous and Neogene formations, as well as tidal cycles, decrease slightly with dredging. Possible applications of similar studies in Geology and environmental analysis are included.
Current evolutionary theory provides detailed accounts of biological diversity, but it still lacks a framework capable of describing the geometric-topological structures in a unified way that living systems produce. Physical and chemical processes can generate only a limited variety of geometric forms, whereas biological morphogenesis explores a much larger and more complex region of morphospace. This distinction has important implications for paleobiology, the biology, and astrobiology: if life produces geometries unavailable to physical-chemical non-living processes, then geometry itself may serve as a universal biosignature. I argue that developing a general morphogeometric theory of life is both conceptually necessary and practically valuable for identifying life in the geological record and beyond Earth.
The Triassic to Early Jurassic fore-arc basin successions of the coastal region of Central Chile (approximately 32 degrees 14' South latitude) form a continuous belt of sedimentary and volcanic rocks, younging to the south. This belt includes, from north to south, the El Quereo, Pichidangui, El Puqu & eacute;n, and Los Molles formations. This note addresses: i) the facies associations and tectonic setting of the El Puqu & eacute;n Formation and the uppermost strata of the underlying Pichidangui Formation, and ii) the first two Rhaetian zircon U-Pb laser-ablation dates of approximately 201 to 208 Ma on volcanic samples from the former, which are younger than the currently accepted Norian-Carnian ages. Basaltic-andesitic lava domes, hyaloclastites and peperites in the uppermost facies of the Pichidangui Formation were emplaced in a subaqueous environment (lacustrine or marine?). Currently these are considered a subduction-related, bimodal volcanic succession synchronous with rifting. Seven facies associations are identified in the conformably overlying lacustrine deposits of the El Puqu & eacute;n Formation, including storm deposits accumulated in a synsedimentary graben approximately 15 m wide, slump deposits, turbidites, pyroclastic intercalations, sedimentary dikes, peperites, and hyaloclastites.
An ammonoid biostratigraphic analysis was conducted for the Permian Olinal & aacute; Formation, Guerrero state, southern Mexico. Bed-by-bed sampling yielded 113 ammonoids belonging to 14 different taxa. The biostratigraphic analysis allowed us to identify two ammonoid Zones: Paraceltites elegans and Coahuiloceras sp., and one subzone: Pseudagathiceras spinosum. According to the GSSP-defined boundaries, these biostratigraphic zones extend from the Roadian-Wordian to the lower Capitanian interval. To support the biostratigraphic analysis, several key taxa were reviewed from a taxonomic perspective. This taxonomic assessment validated the genus Coahuiloceras. A quantitative analysis based on morphometric ratios of the species of the genera Timorites and Coahuiloceras reveals a clear divergence between both groups. In addition, the biostratigraphic framework of the Olinal & aacute; succession is compared with previously published biostratigraphic data from Sonora, Coahuila and Texas, highlighting similarities and differences among these areas. The identified fauna in the Olinal & aacute; Formation is mainly associated with the American Realm.
Because of the convergence of Africa and Eurasia and the opening of the Atlantic Ocean, the Gulf of Hammamet, which makes up the southwestern portion of the Mediterranean, experienced significant relative sea-level fluctuations and eustatic variations during the late Cenozoic. The sedimentary successions deposited between the Late Miocene and the earliest Pleistocene in the Gulf of Hammamet preserve precious environmental and climatic information. The present paper focuses on the latest Messinian to Gelasian deposits of the Jiriba-1 borehole, which is located off the coast of Tunisia. Here, previous datings obtained through planktonic foraminiferal biostratigraphy are calibrated chronologically on a high-resolution scale. Palynological analysis based on the spores and pollen content of the borehole allows for reconstructing the environmental and vegetational evolution, as well as establishing a precise climatostratigraphic framework for the study area. The latest Messinian to Gelasian palynological record is comprised of abundant continental (pollen and spores) and marine (dinoflagellate cysts) inputs. Distality markers (halophytes, D/S, Pinus, and dinoflagellate cysts) indicate that the Gulf of Hammamet was an epicontinental setting that evolved from a proximal to a distal neritic environment. The Lygeum, Artemisia, and S/T ratio curves enable climatostratigraphic correlations with northwestern Europe, the northwestern Mediterranean, and the Black Sea. Furthermore, the climatic evolution depicted by the steppe elements (Artemisia and Ephedra) from the Jiriba-1 borehole shows parallelisms with the delta 18O isotope curve. The vegetation cover was open, dominated by herbaceous plants that inhabited the lower altitudes, and developed into mixed forest-plant formations at mid-altitudes. Between these two formations, a group of trees made up of Mediterranean species was present. Repetitive changes in vegetation as well as relative sea-level fluctuations in the Gulf of Hammamet suggest that these cyclical variations resulted from the influence of astronomical forcing.
Upper Barremian-lower Aptian Urgonian-type platform carbonates from Ard & egrave;che yield a rich rudist fauna belonging to the families Requieniidae, Monopleuridae, Caprinidae, and Polyconitidae. The upper Barremian assemblage from the Ard & egrave;che river gorges consists of eighteen species, it conforms to the Rustrel fauna of the Monts-de-Vaucluse but contains a new genus Valclusella, and a new species of Bicornucopina, a genus unknown so far in Western Europe, whereas Mathesia darderi is identified for the first time in SE France. We define the "Saint-Montan limestones", of early Aptian age, as the uppermost member of the Urgonian Formation in this region. The corresponding Saint-Montan fauna is described for the first time: it contains twenty-five rudist species, of which eight are new and seventeen are inherited from the antecedent late Barremian Orgon and Rustrel fossil type localities. Of the eight new species, two are ascribed to earlier genera, i.e., Homopleura parva and Bicornucopina acuminata, three are assigned to a new genus, Myostyla ardescensis, while Valclusella valclusensis and Valclusella biconvexa preexisted in the late Barremian. Aside from inherited taxa, e.g., Pachytraga paradoxa, Praecaprina varians-gaudryi, Caprina douvillei, important novelties regard the Caprinidae, characterized by the appearance of probable new species of Pachytraga, P. aff. paradoxa, Offneria, O. aff. rhodanica, and three new species of Praecaprina: Pr. tubifera n. sp., Pr. paquieri n. sp., and Pr. vacua n. sp. The early Aptian p.p., therefore, coincides with the acme of the genus Praecaprina, SE France being unique in this respect. In the Saint-Montan fauna, up to about nine species from the Rustrel fauna are missing. The Saint-Montan rudist assemblage is unique, thus far, in SE France, even as the study of its composition is still in progress. It has a West European character, similar to that of its antecedent late Barremian one, and the succeeding late early Aptian Villaroya de los Pinares fauna from Spain, but the three have distinctive taxonomic compositions. The Saint-Montan stratigraphic succession is framed by two drowning boundary events. The taxonomic composition of its rudist assemblage fills a gap between the late Barremian and the late early Aptian faunas, and represents a distinctive episode in the Barremian-lower Aptian Urgonian-type rudist sequence of southern France and Spain, and possesses a significant biostratigraphic potential.
Regular growth increments have been identified in the epitheca of the Bathonian solitary coral Montlivaltia LAMOUROUX, 1821. Examination of a large population of specimens from several outcrops across Lorraine (France) shows that these cyclic patterns are recurrent and can be consistently recognized. The dimensional ratios between successive increments suggest that the observed periodicities reflect lunar cycles nested within annual growth rhythms. This interpretation allows for the estimation of coral age and provides a means to document how morphological parameters vary through ontogeny. It therefore offers a valuable alternative to the debated practice of using size as a proxy for age in evolutionary studies. Finally, the regularity of the growth cycles further supports the view that Montlivaltia was solitary but probably harbored zooxanthellae.
Despite the common and widespread occurrence of turtle shell remains in many fossil vertebrate assemblages worldwide, few palaeontological studies have addressed the palaeoecological significance of turtle bone modification features. Here, we report on ichnofossils occurring on carapacial and plastral bones of the small terrapin genus Mauremys (Testudinoidea, Geoemydidae) from Upper Pliocene deposits exposed at La Serra, in the Valdelsa basin of Tuscany (central Italy). The trace fossil assemblage includes Karethraichnus lakkos, Gunnellichnus cf. moghraensis, and Thatchtelithichnus holmani, all of which are found on the nonvisceral surfaces of the shell. As observed elsewhere, some of the Karethraichnus lakkos borings occur along the epidermal sulci that mark the border between adjacent keratinous scutes. Based on the relevant literature, the studied ichnofossils are interpreted as being due to the parasitic action of leeches/spirorchiid liver flukes (K. lakkos and Thatchtelithichnus holmani) and to algal/fungal/bacterial (sub)cutaneous infections (Gunnellichnus cf. moghraensis). The observed stock of bioerosional features compares favourably with the Italian Pliocene climate, which was warmer and wetter than today.
Despite the common and widespread occurrence of turtle shell remains in many fossil vertebrate assemblages worldwide, few palaeontological studies have addressed the palaeoecological significance of turtle bone modification features. Here, we report on ichnofossils occurring on carapacial and plastral bones of the small terrapin genus Mauremys (Testudinoidea, Geoemydidae) from Upper Pliocene deposits exposed at La Serra, in the Valdelsa basin of Tuscany (central Italy). The trace fossil assemblage includes Karethraichnus lakkos, Gunnellichnus cf. moghraensis, and Thatchtelithichnus holmani, all of which are found on the nonvisceral surfaces of the shell. As observed elsewhere, some of the Karethraichnus lakkos borings occur along the epidermal sulci that mark the border between adjacent keratinous scutes. Based on the relevant literature, the studied ichnofossils are interpreted as being due to the parasitic action of leeches/spirorchiid liver flukes (K. lakkos and Thatchtelithichnus holmani) and to algal/fungal/bacterial (sub)cutaneous infections (Gunnellichnus cf. moghraensis). The observed stock of bioerosional features compares favourably with the Italian Pliocene climate, which was warmer and wetter than today.
The Lower and lower Middle Jurassic carbonates from the southern margin of the Moroccan High Atlas yielded well-preserved foraminifers and calcareous algae. The identification of these micro-fossils, based on thin-section observations, allowed us to define seven successive micropaleontological assemblages with ages from the early Sinemurian to the early Bajocian. These micropaleontological assemblages, relatively well calibrated by ammonites and brachiopods, were compared with the larger foraminiferal biozonation of SEPTFONTAINE (1984) for the Moroccan Tethys domain. A new biozone with Palaeodasycladus mediterraneus is introduced to characterize the upper Pliensbachian (Algovianum Zone) to lower Toarcian interval.
The green alga Palaeodasycladus (PIA, 1920) was recognized in shallow marine, high-energy calcarenites from the Lower Jurassic Cho & ccaron; Nappe (Hronicum domain) in the Tatra Mountains of Poland. The algal structure is described here. The calcareous skeleton has a regular internal cavity, probably close to the central axis, but very irregular outwardly, enveloping the primary laterals at different lengths. The general shape of the thallus is spherical, with only long, acrophorous primary laterals, probably forming a distal cortex. The external gametophores are attached laterally to the primary laterals. The characteristics allow the alga to be assigned not to Palaeodasycladus (PIA, 1920) but to Goniolina ORBIGNY, 1850. The new species Goniolina tatrarum n.sp. is here established. A critical review of the genus Goniolina ORBIGNY, 1850, and its type species is also provided. The genus Goniolina ORBIGNY appears to have been represented so far solely by G. hexagona ORBIGNY, 1850. G. geometrica BUVIGNIER, 1852, and G. micraster BUVIGNIER, 1852, are considered valid and separate species to be assigned to Coniporella FISHER & THIERRY, 1971. Sphaerites regularis QUENSTEDT, 1852, a supposed junior synonym of Goniolina geometrica (ROEMER, 1839), is provisionally assigned to the genus Tersella J. MORELLET in J. MORELLET & TERS, 1952, and indicated as Tersella (?) regularis (QUENSTEDT, 1852).
The Paleogene succession of the Esparron syncline consists of three superimposed stratigraphic units, in ascending order: (1) a lacustrine-palustrine-dominated basal unit (BU) bearing channels filled by limestone breccias at base, (2) fluvial deposits of the lower Molasse Rouge Formation (MR1), and (3) well-rounded polygenic conglomerates, bearing Alpine "green rocks" and radiolarites overlain by red clays in the upper Molasse Rouge Formation (MR2). Breccia deposits of the basal unit represent a multi-channeled torrential system generally sloping to the northeast. However, the regional extent and character of the BU is difficult to determine due to its truncation by the basal surface of MR1. Around the northwestern termination of the Esparron syncline the succession is complete and 200 m thick. Basal breccias of the BU pass upward to reddish fluvial overbank mudstones, then to grayish lacustrine-palustrine limestones, and back to reddish silty claystones. Field data suggest that this unit cannot be proximal deposits of the "Nummulitic foreland basin", but is younger, just predating deposition of the MR1, likely in the late Rupelian. These also cannot be proximal deposits of MR1, as formerly suggested. They constitute a fully distinct tectono-stratigraphic sequence whose deposition cannot be understood without a broad regional synthesis (in preparation). Along the southern flank of the syncline, MR1 has a sheet geometry featuring amalgamated fluvial point bar deposits at the base, which are overlain by the deposits of a large fluvial fan prograding to the west. MR1 deposits abruptly pinch out along the northern flank of the syncline, and are interpreted as having filled a paleovalley that roughly matches the E-W orientation of the syncline. South of the syncline, in the Esclangon and Hautes Duyes areas, the same succession is found but the meandering fluvial deposits of Esparron are lacking at the base of MR1. Here, MR1 deposits are represented by fluvial fan deposits prograding to the west, but have a more proximal character than at Esparron. In this area, the MR1unit is capped by the Molasse Grise (MG), which represents a flattening of the depositional profile after the progradation of the underlying fluvial fan. Across the entire region, MR2 deposits are thin, and likely truncated by the main Digne thrust. They are deposited disconformably on top of either MR1 or directly on folded Mesozoic deposits, suggesting that erosion and tectonic activity occurred between deposition of MR1 and MR2. The occurrence of well-rounded pebbles of Alpine "green rocks" and radiolarites in the basal fluvial conglomerate of MR2 indicates that the system had a large watershed that encroached the inner Alps, probably during uplift of the latter. In the Ainac area, the braided fluvial facies at the base of MR2 acquired a more distal character with channels filled by either conglomerates or a more sand-prone facies. The vertical facies trend in MR1 and MR2 suggests that a low-gradient fluvial setting was followed by regional uplift responsible for the progradation of fluvial fans. The two stratigraphic units are therefore regarded as tectono-stratigraphic sequences, in response to changes in the Alpine stress regime. With unit 1 (BU), the Molasse Rouge is therefore composed of three independent sequences. Finally, the ages of the MR1 and MR2 deposits are revised, both to Chattian and probably not extending into the Aquitanian, as previously reported for the MR2. Geometric relationships suggest that the three continental Paleogene sequences record a changing depositional setting controlled by both active tectonics and intervening periods of quiescence in a time interval grossly bracketing the late Rupelian and the Chattian.
