Microstructural evidence of the stylophyllid affinity of the genus Cyathophora (Scleractinia, Mesozoic)

The genus Cyathophora Michelin, 1843 (Cyathophoridae) is removed from the suborder Stylinina Alloiteau, 1952 and transferred to the Stylophyllina Beauvais, 1980. Morphologically, it differs from stylinine corals in that rudimentary septa are developed in the form of ridges or spines on the wall and may continue onto the endothecal elements as amplexoid septa. Relics of primary aragonite microstructure, preserved in silicified colonies of Cyathophora steinmanni Fritzsche, 1924 (Barremian–early Aptian) and in a calcified colony of C. richardi Michelin, 1843 (middle Oxfordian), indicate a non-trabecular structure of their skeletons. The sclerenchyme of radial elements is differentiated into fascicles of fibres, and in the form of fascicles or a non-differentiated layer of fibres, it continues as the upper part of endothecal elements and as the incremental layers of the wall. A micro-lamellation of the skeleton corresponds to the accretionary mode of skeleton growth found in Recent corals. A similarity between the septal microstructure of Cyathophora and that of the stylophyllid genera, the Triassic Anthostylis Roniewicz, 1989 and the Triassic–Early Jurassic Stylophyllopsis Frech, 1890, is interpreted as a result of their being phylogenetically related. The microstructure of the Jurassic Stylina gaulardi Michelin, 1843 has been considered for purposes of comparison. The systematics of the genus Cyathophora is formally revised with C. richardi Michelin reinstated as the type species

Oxfordian to Valanginian palaeoenvironmental evolution on the western Moesian Carbonate Platform : a case study from SW Bulgaria

Three sections (Rebro, Lyalintsi and Velinovo) of the Upper Jurassic-Lower Cretaceous carbonate sequences from the Lyubash unit (Srednogorie, Balkanides, SW Bulgaria) have been studied for elucidation of biostratigraphy and palaeoenvironmental evolution. Palaeontological studies of foraminifera, supplemented by studies of calcareous dinoflagellate cysts and corals, enabled the determination of the Oxfordian-Valanginian age of the analysed sequences. They were deposited on the Dragoman Block (western part of the Moesian Platform), and during Mid-Late Cretaceous included to the Srednogorie. A possible Middle to Late Callovian age of the lowermost part (overlying the Bajocian-Lower Bathonian Polaten Formation) of the studied sections assumed till now has not been confirmed by the present studies. Eleven facies have been distinguished and attributed to depositional environments. Marine sedimentation on a homoclinal ramp started in the Oxfordian and till the Early Kimmeridgian - in all three sections - was dominated by fine-grained peloidal-bioclastic wackestones to grainstones. Since the Late Kimmeridgian, when a rimmed platform established, facies pattern underwent differentiation into (i) the inner platform (lagoon and tidal flat facies) - only in Velinovo, (ii) reef and peri-reef facies/bioclastic shoals - mainly in Lyalintsi, and (iii) platform slope - mainly in Rebro. Sedimentation generally displays a shallowing-upward trend. Two stages in evolution of the rimmed platform are postulated. The mobile stage lasting till the Tithonian/Berriasian boundary was followed by a more stable stage in the Berriasian to Valanginian time. Reefs are developed mainly as coral-microbial biostromes, lower coral bioherms or coral thickets, in the environment of moderate energy and sedimentation. They contain highly diversified corals (72 species). Micro- bialites contributed to the reef framework, but they never dominated. Locally, microencrusters and cement crusts formed important part of reefal framework. During the mobile stage of the platform evolution a relative sea-level rise interrupted reef development, as evidenced by intercalations of limestones with Saccocoma. During the second stage high carbonate production and/or regressive eustatic events, not balanced by subsidence, decreased accommodation space, limiting reef growth and enhancing carbonate export to distal parts of the platform

Mentors : the generation 1935-1985

The lives and scientific contributions of five eminent academic geologists and paleontologists; James Alloiteau (Museum National d’Histoire Naturelle, Paris, France), Dorothy Hill (University of Queensland, Australia), Marius Lecompte (University of Louvain, Belgium), Masao Minato (Hokkaido University, Sapporo, Japan), and Maria Różkowska (Adam Mickiewicz University, Poland) are briefly summarized here. Each of these paleontologists made major contributions to the study of fossil corals and/or sponges, and each overcame considerable difficulties and disruptions in their lives to excel as mentors to us. All showed remarkable determination and love for paleontological research, and inspired their students and colleagues to understand details of structure and systematic positions of fossil corals and sponges. Each of these individual mentors was the subject of a presentation by a former student at the 11th International Symposium on Fossil Corals and Sponges in Liege, Belgium; thus, somewhat broader coverage of each is provided in the abstracts volume of the meeting

First record of Rhabdoceras suessi (Ammonoidea, Late Triassic) from the Transylvanian Triassic Series of the Eastern Carpathians (Romania) and a review of its biochronology, paleobiogeography and paleoecology

Abstract The occurrence of the heteromorphic ammonoid Rhabdoceras suessi Hauer, 1860, is recorded for the first time in the Upper Triassic limestone of the Timon-Ciungi olistolith in the Rarău Syncline, Eastern Carpathians. A single specimen of Rhabdoceras suessi co-occurs with Monotis (Monotis) salinaria that constrains its occurrence here to the Upper Norian (Sevatian 1). It is the only known heteromorphic ammonoid in the Upper Triassic of the Romanian Carpathians. Rhabdoceras suessi is a cosmopolitan species widely recorded in low and mid-paleolatitude faunas. It ranges from the Late Norian to the Rhaetian and is suitable for high-resolution worldwide correlations only when it co-occurs with shorter-ranging choristoceratids, monotid bivalves, or the hydrozoan Heterastridium. Formerly considered as the index fossil for the Upper Norian (Sevatian) Suessi Zone, by the latest 1970s this species lost its key biochronologic status among Late Triassic ammonoids, and it generated a controversy in the 1980s concerning the status of the Rhaetian stage. New stratigraphic data from North America and Europe in the subsequent decades resulted in a revised ammonoid biostratigraphy for the uppermost Triassic, the Rhaetian being reinstalled as the topmost stage in the current standard timescale of the Triassic. The geographic distribution of Rhabdoceras is compiled from published worldwide records, and its paleobiogeography and paleoecology are discussed

Multiple low-temperature thermochronology constraints on exhumation of the Tatra Mountains: New implication for the complex evolution of the Western Carpathians in the Cenozoic

The tectonothermal evolution of the highest mountain range in the Carpathian arc—the Tatra Mountains— is investigated by zircon and apatite fission track and zircon (U-Th)/He (ZHe) dating methods in order to unravel the disputed exhumation and geodynamic processes in the Western Carpathians. Our data in combination with geological evidences reveal a complex Cenozoic history, with four major tectonothermal events: (i) a very low grade metamorphism of the crystalline basement at temperatures >240°C due to tectonic burial during the Eo-Alpine collision in the Late Cretaceous (~80 Ma); (ii) exhumation and cooling of the basement to temperatures 150°C after burial to 5–9 km depths by the Paleogene fore-arc basin; (iv) final exhumation of the segmented basement blocks during Oligocene-Miocene (32–11 Ma) owing to lateral extrusion of the North Pannonian plate and its collision with the European foreland. The spatial pattern of thermochronological data suggests asymmetric exhumation of the Tatra Mountains, beginning in the northwest at ~30–20 Ma with low cooling rates (~1–5°C/Ma) and propagating toward the major fault bounding the range in the south, where the youngest cooling ages (16–9 Ma) and fastest cooling rates (~10–20°C/Ma) are found. Our data prove that the Tatra Mountains shared Cenozoic evolution of other crystalline core mountains in the Western Carpathians. However, the Miocene ZHe ages suggest that the Tatra Mountains were buried to the greatest depths in the Paleogene-Early Miocene and experienced the greatest amount of Miocene exhumation

Early Norian (Triassic) corals from the Northern Calcareous Alps, Austria, and the intra-Norian faunal turnover

The first description of early Norian coral fauna from the Northern Calcareous Alps (Dachstein Plateau and Gosaukamm), Austria, is presented: 31 scleractinian species from 24 genera (including three corals not formally determined), and three hexanthiniarian species belonging to two genera. The stratigraphical position of the main part of the fauna discovered in the South Dachstein Plateau at the Feisterscharte is determined by means of the conodont Epigondolella quadrata (Lacian 1); single finds are from the horizons with Epigondolella triangularis and Norigondolella navicula (Lacian 3), and one close to the horizon with Epigondolella cf. multidentata (Alaunian 1). Rare corals from the Gosaukamm are from the Lacian 1 and Alaunian. Five species are described as new: Retiophyllia vesicularis, Retiophyllia aranea, Margarosmilia adhios, Hydrasmilia laciana; one new genus and species from the family Coryphylliidae, Margarogyra hirsuta; one new genus and species, Thamnasterites astreoides, cannot be assigned to a family. Two hexanthiniarian species, Pachysolenia cylindrica and Pachydendron microthallos, known exclusively from the Tethyan lower Norian, represent stratigraphically valuable species. A regularly porous coral from the family Microsolenidae, Eocomoseris, which up to now has only been known from the Jurassic and Cretaceous, is here identified from the Triassic strata (originally described as Spongiomorpha [Hexastylopsis] ramosa). Predominant taxa show solitary and phaceloid (pseudocolonial) growth forms and an epithecal wall; pennules−bearing corals are common. Carnian genera and genera typical of the Lacian and Lacian–early Alaunian prevail; a hydrozoan genus Cassianastraea has also been encountered as well as a scleractiamorph coral, Furcophyllia septafindens). The faunal composition contrasts with that of well known late Norian–Rhaetian ones, the difference being observed not only at the generic but also at the family level. The post−early Norian change in coral spectrum documents the turnover of the coral fauna preceding that at the Triassic/Jurassic boundary