Micropaleontological observations on the Lower Cretaceous iron ore-related formations of the Mecsek Mts. (Upper Valanginian–Lower Hauterivian, South Hungary)

The Late Valanginian–Early Hauterivian iron ore deposit and related formations at Zengővárkony (Mecsek Mts., South Hungary) provided a relatively rich microfauna of foraminifera, crustacean microcoprolites, and sponge spicules. Benthic foraminifera are recognized in decreasing abundance: Glomospira cf. gordialis (Jones and Parker 1860), Lenticulina sp., Spirillina sp., Nodosaria sp., Epistomina sp., and Trocholina sp. A Hedbergella sp. indicates the presence of planktonic foraminifera around the ore deposit. Besides this microfauna, sponge spicules (diactine-type criccorhabds and anactine-type rhax forms) are first recorded from this environment. Rock-forming quantities of various ichnospecies of crustacean microcoprolites are recorded. Favreina hexaochetarius, Palaxius tetraochetarius, and Palaxius decaochetarius isp. provided statistically evaluated quantities in thin sections, which point to a complete crustacean ichnofauna from juveniles to adults. Four different microfossil assemblages are recognized from the Apátvarasd Limestone Fm: (a) Glomospira-dominated foraminifer assemblage, (b) diverse crustacean microcoprolite assemblage dominated by Palaxius, (c) monotypic Favreina assemblage, and (d) diverse sponge-dominated assemblage. These assemblages are similar to that of the Recent Aegean Sea hydrothermal field communities. The remains of an undetermined crinoid from dissolved rock sample may indicate a vivid sea-bottom environment

Systématique, phylogénie et homéomorphie des Engonoceratidae HYATT, 1900 (Ammonoidea, Crétacé) et révision de Engonoceras duboisi LATIL, 1989

Les Enganoceratidae apparaissent à l'Albien basal (ou peut-être dès l'Aptien terminal) dans les séries de plates-formes carbonatées de la marge sud de la province méditerranéenne du domaine téthysien. Leur efficacité évolutive leur permet de coloniser rapidement l'ensemble du domaine téthysien et même au delà comme le montre la présence de groupes endémiques dans le Bassin Péruvien et dans la mer intérieure occidentale des États-Unis. Plus tard, le groupe élargira encore plus son aire de distribution en envahissant certaines régions du domaine boréal (mer de Mowry, Canada). Les Enganoceratidae semblent avoir eu un mode de vie nectoplanctonique, épipélagique et sténohalin au sein de mers chaudes peu à très peu profondes (rivages, lagons), dont la fréquence a favorisé leur évolution. Ce groupe, dont l'origine est obscure, est bien individualisé. Il comprend neuf genres et une centaine d'espèces. Leur apparition semble avoir été provoquée par la crise anoxique OAE 1b et leur rapide expansion favorisée par l'extension progressive des mers chaudes et épicontinentales qui accompagne la montée des eaux du milieu du Crétacé. Le déclin des Enganoceratidae semble lié à l'accélération de la montée des mers qui caractérise la fin du Cénomanien, sans doute par modification substantielle de leurs habitats peu profonds. Ce groupe est considéré comme un colonisateur efficace et un bon indicateur de milieux de faible profondeur en ambiance transgressive. À partir de nouvelles études stratigraphiques et structurales, il est proposé une révision de l'espèce Engonoceras duboisi qui doit être rattachée au genre Parengonoceras. Par ailleurs, il est mis en évidence que le fait de présenter des sutures simplifiées de type Cératite et une coquille lancéolée à oxycône comprimé est symptomatique d'ammonites adaptées à des milieux marins peu profonds. Ce modèle est, en effet, répété trois fois au long de l'évolution des Ammonoïdes mésozoïques.The Engonoceratidae may well have originated on the shallow marine carbonate platforms of the southern margin of the Mediterranean Province of the Tethyan Realm during the earliest Albian (?latest Aptian). In the entire Tethyan Realm and beyond adaptive radiation of the group was rapid and successful during the early Albian as indicated by endemic centres in the Peruvian Basin and the Western Interior Sea (USA). Later the group successfully enlarged its distribution, and invaded some provinces (Mowry Sea, Canada) of the Boreal Realm. The mode of life of engonoceratids seems to have been nektoplanktonic, epipelagic, and stenohaline, restricted to shallow water and platform or in some cases extremely shallow (littoral and lagoonal) facies which may have helped their radiation. The group is distinctive and consists of nine genera and up to a hundred species, although its origin is still obscure. Their appearance may have been triggered by the oceanic anoxic event (OAE 1b) and their rapid rise may have been helped by their shallow water mode of life and the global mid-Cretaceous warming and rise in sea level. The fall of the engonoceratids coincides with the end-Cenomanian rapid transgression, which may have changed their shallow water habitats. Today the group is considered to have been a successful colonizer, a reliable stratigraphical indicator for shallow marine environments and a pioneer taxon for recognition of transgressive phases. Based on new material and sutural analysis, Engonoceras duboisi is revised and assigned to Parengonoceras. A set of features consisting of a simplified ceratitid suture, lanceolate and compressed oxycone shell together comprising a shallow marine ecotype is pointed out as a successful and repeated morphotype among Mesozoic Ammonoidea, for it was repeated three times during ammonoid evolution

A unique Valanginian paleoenvironment at an iron ore deposit near Zengővárkony (Mecsek Mts, South Hungary), and a possible genetic model

Abstract The spatially restricted Early Valanginian iron ore (limonite) and manganese deposit at Zengõvárkony (Mecsek Mts, southern Hungary) contains a rich, strongly limonitized, remarkably large-sized (specimens are 30–70% larger than those at their type localities) brachiopod-dominated (mainly Lacunosella and Nucleata) megafauna and a diverse crustacean microfauna, which indicates a shallow, nutrient-rich environment possibly linked to an uplifted block, and/or a hydrothermal vent

Systematics, phylogeny and homeomorphy of the Engonoceratidae Hyatt, 1900 (Ammonoidea, Cretaceous) and revision of Engonoceras duboisi Latil, 1989

The Engonoceratidae may well have originated on the shallow marine carbonate platforms of the southern margin of the Mediterranean Province of the Tethyan Realm during the earliest Albian (?latest Aptian). In the entire Tethyan Realm and beyond adaptive radiation of the group was rapid and successful during the early Albian as indicated by endemic centres in the Peruvian Basin and the Western Interior Sea (USA). Later the group successfully enlarged its distribution, and invaded some provinces (Mowry Sea, Canada) of the Boreal Realm. The mode of life of engonoceratids seems to have been nektoplanktonic, epipelagic, and stenohaline, restricted to shallow water and platform or in some cases extremely shallow (littoral and lagoonal) facies which may have helped their radiation. The group is distinctive and consists of nine genera and up to a hundred species, although its origin is still obscure. Their appearance may have been triggered by the oceanic anoxic event (OAE 1b) and their rapid rise may have been helped by their shallow water mode of life and the global mid-Cretaceous warming and rise in sea level. The fall of the engonoceratids coincides with the end-Cenomanian rapid transgression, which may have changed their shallow water habitats. Today the group is considered to have been a successful colonizer, a reliable stratigraphical indicator for shallow marine environments and a pioneer taxon for recognition of transgressive phases.Based on new material and sutural analysis, Engonoceras duboisi is revised and assigned to Parengonoceras. A set of features consisting of a simplified ceratitid suture, lanceolate and compressed oxycone shell together comprising a shallow marine ecotype is pointed out as a successful and repeated morphotype among Mesozoic Ammonoidea, for it was repeated three times during ammonoid evolution

Early Cretaceous brachiopods from a hydrothermally influenced environment of the Mecsek Mountains (Zengővárkony, southern Hungary) and their palaeobiogeographical relationships

New material and the investigation of old collections provided some 150 specimens of Early Cretaceous brachiopods from the Mecsek Mountains, Hungary. Taxonomic evaluation resulted in the identification of some species previously unknown from Hungary and confirmed the presence of some previously described species, too. In this paper Fortunella cf. fortunae Calzada, 1985, Lacunosella hoheneggeri (Suess, 1858), Monticlarella remesi Nekvasilova, 1977, Moutonithyris moutoniana (d’Orbigny, 1847), Karadagella ? aff. bilimeki (Suess, 1858), Nucleata veronica Nekvasilova, 1980 are described. This fauna is rather endemic. All the specimens reveal a unique phenomenon: they exhibit 25–70% larger average dimensions compared to populations of their closest relatives or type localities. The uniform size increase of these brachiopods may be linked to hydrothermal processes of the sea-floor. Lately, a discovery from the Tyrrhenian Sea offers a Recent, present day analogue to this enigmatic palaeoenvironment. Palaeobiogeographic comparison of this small endemic fauna with eight others, mainly Hauterivian and Tethyan brachiopod assemblages reveals the distinct Sub-Tethyan domain consisting of the faunas from Zengővárkony, Codlea (Eastern Carpathians) and Štramberk (Czechia). This strengthens previously described affinities and relationships of these faunas and helps to clarify the Cretaceous palaeogeographic position of the Mecsek Mountains

Fauna, palaeoecology and ecotypes of the Early Cretaceous sediment hosted hydrothermal vent environment of Zengővárkony (Mecsek Mountains, Hungary)

The fossil biota of the upper Valanginian–lower Hauterivian sediment hosted vent (SHV) environment of Zengővárkony comprises 39 species, 55 genera and higher taxa representing seven phyla. Thirteen of these taxa are reported from Zengőrvárkony as new species or new subgenera/genera, and this high endemicity is linked to a unique palaeoenvironment. The palaeoenvironment is developed in an outer shelf epicontinental setting on an elevated block or slope, and is linked to a small sedimentary iron-ore body interbedded with pillow lavas being a result of ferriferous exhalations and biogenic processes. Biogeographically, the brachiopods indicate the Sub-Tethyan domain. Serial sectioning of brachiopods revealed a taxon-dependent rich and diverse microfauna (sponges, foraminifers, gastropods) preserved inside the shells. Internally preserved microfauna in brachiopods reveals differentiation among preventive strategies. It implies different preventive efficiencies of alternative defence strategies of higher brachiopod taxa. The unique Zengővárkony SHV environment attracted both nektonic and benthic organisms by creating different ecotopes around the hydrothermally driven bottom environment. This environment belongs to the group of rare, shelfal, hydrothermally influenced palaeoenvironments formed on continental crust. Water depth was most probably between 100 and 150 m. Recent observations from a similar modern volcanic built-up, and its effects on the marine environment located on continental crust around the Aeolian Islands (Tyrrhenian Sea) support the recognition of this fossil SHV environment and helps to understand better its bathymetry, ecological conditions and ore-formation

New Kingenoid Brachiopods from the Early Cretaceous Iron Ore Related Environment of Zengővárkony (Mecsek Mts, Hungary, Europe)

The Lower Cretaceous tiny iron ore deposit at Zengővárkony (Mecsek Mts, South Hungary, Europe) provided new brachiopod taxa of Kingenoid relationship. Dictyothyropsis vogli nov. sp, Zittelina hofmanni nov. sp. and Smirnovina ferraria nov. sp. are introduced representing Late Valanginian to Earliest Hauterivian age. The new taxa strengthen the presence of the Early Cretaceous biogeographical connections with the Western Carpathians and the Pieniny Klippen Belt of South Poland. The biometry of the newly described taxa refer to significantly greater mean dimensions, which is in line with previous research on brachiopods from this environment. These brachiopods lived in a nutrient-rich unique environment related to the iron-ore deposition linked to a former hydrothermal activity on the ocean floor that resulted the size growth of brachiopods

Latest Oxfordian – earliest Kimmeridgian ammonite dominated fauna and microfacies from the ammonitico rosso-type Fonyászó Limestone Formation at Zengővárkony (Mecsek Mountains, Hungary)

Field work has resulted in the recognition of a previously unknown outcrop in the vicinity of the Zengővárkony lime-kilns (Mecsek Mountains, South Hungary) which has provided a remarkably rich, but poorly preserved, uppermost Oxfordian – earliest Kimmeridgian fauna dominated by ammonites probably representing the Hypselum–Bimammatum zones. This is the first description and illustration of Oxfordian–Kimmeridgian ammonites from the Mecsek Mountains. The cephalopod fauna comprises Phylloceras div. sp., Holcophylloceras div. sp., Sowerbyceras sp., Lytoceras sp., Lissoceratoides erato, Trimarginites cf. trimarginatus, Glochiceras (Coryceras) cf. microdomum, Subdiscosphinctes sp., ?Wegelea sp., Passendorferiinae gen. et sp. ind., ?Orthosphinctes sp., Euaspidoceras cf. radisense, Aspidoceras sp., A. cf. binodum, Physodoceras sp. ex gr. altenense-wolfi, Lamellaptychus sp., Laevaptychus sp. ex gr. hoplisus-obliquus. The fauna has a Mediterranean character (55% of Phylloceratidae and Lytoceratidae) and is similar to the Tethyan assemblages of the Venetian Alps (Italy), and Palma de Mallorca. The spirochaete tube worm Spiraserpula spirolinites is also the first record from the Mecsek Mountains. The Saccocoma wackestone-packstone microfacies is recorded with benthic foraminifera (Lenticulina sp. and Spirillina sp.) indicating well oxygenated and nutrient-rich bottom conditions

Aptian-Campanian ammonites of Hungary

Studies on the Cretaceous ammonites of Hungary had been started in the second half of the XIXth century with the finding of the impressive fossil assemblage of “Schichten von Nána” (HAUER 1862). Since then, Cretaceous ammonite studies are in the mainstream of the Hungarian palaeontology (HANTKEN 1868; LÓCZY 1906; BÖCKH 1909; KOCH 1909; SOMOGYI 1914; NOSZKY 1934, 1942; NAGY I. Z. 1973; SCHOLZ 1975, 1979; HORVÁTH, A. 1985, 1989; BUJTOR 1989, 1990a, 1990b, 1991; FŐZY 2001, 2004; FŐZY & FOGARASI 2002; FŐZY et al. 2002; FŐZY & JANSSEN 2005, 2006; COMPANY et al. 2006; SZIVES, 1996, 1999a, 1999b, 2002; SZIVES & MONKS 2002). The present monograph of the Aptian–Campanian ammonites of Hungary is a summarising work of unpublished or partly published materials. The studied assemblages are mainly from the collections of the Hungarian Natural History Museum and the Geological Museum of Hungary. The well-known and fully published Vraconian assemblage from surface outcrops of the Bakony Mts is complemented with an unpublished, exceptionally beautiful collection of a qualified private collector, Zoltán Evanics. Before starting to document the Hungarian ammonite record, an outline of the Cretaceous system and geodynamics of the Alp–Carpathian region can help to reconstruct the palaeogeographical situation. The book is divided into chapters according to certain ages as Aptian, Albian, Santonian and Campanian. Each chapter contains a historical outline, a stratigraphic, palaeobiogeographic, palaeoecologic–taphonomic and a systematic part. Both the Aptian and Albian ammonite assemblages from surface outcrops are known from condensed strata. A Late Aptian ammonite record is also documented here from a borehole as well. Fortunately several boreholes with continuous core sampling crossed Albian ammonite-bearing sequences. The Santonian ammonite record of Hungary includes a single specimen. A dozen of ammonites came from Campanian sediments but from a very restricted area