Temperate Realm Research Articles

Rapid in situ diversification rates in Rhamnaceae explain the parallel evolution of high diversity in temperate biomes from global to local scales.

The macroevolutionary processes that have shaped biodiversity across the temperate realm remain poorly understood and may have resulted from evolutionary dynamics related to diversification rates, dispersal rates, and colonization times, closely coupled with Cenozoic climate change. We integrated phylogenomic, environmental ordination, and macroevolutionary analyses for the cosmopolitan angiosperm family Rhamnaceae to disentangle the evolutionary processes that have contributed to high species diversity within and across temperate biomes. Our results show independent colonization of environmentally similar but geographically separated temperate regions mainly during the Oligocene, consistent with the global expansion of temperate biomes. High global, regional, and local temperate diversity was the result of high in situ diversification rates, rather than high immigration rates or accumulation time, except for Southern China, which was colonized much earlier than the other regions. The relatively common lineage dispersals out of temperate hotspots highlight strong source-sink dynamics across the cosmopolitan distribution of Rhamnaceae. The proliferation of temperate environments since the Oligocene may have provided the ecological opportunity for rapid in situ diversification of Rhamnaceae across the temperate realm. Our study illustrates the importance of high in situ diversification rates for the establishment of modern temperate biomes and biodiversity hotspots across spatial scales.

Origin, diversification, and biogeography of forest birds across temperate forest regions in the Northern Hemisphere

Technological and methodological advances in biogeography, phylogenetics, and bioinformatics during the past couple of decades provide greatly enhanced insights into the evolutionary history of birds in space and time. Molecular data, especially next-generation DNA sequencing, have produced a revolution in reconstructing the phylogenetic history of lineages. These advances shed a new light on the mode, tempo, and spatial context of differentiation processes that shaped the composition and structure of extant forest bird communities of temperate forests of the Northern Hemisphere. This paper offers a framework for understanding this history based on analytical tools that allow us to decipher the imprint of changes in the geographic configuration of land masses and in climates since the Mesozoic, with a focus on the temperate-tropical flyways that connect the massive forest blocks of the Northern to those of the Southern Hemispheres. Differentiation of most extant bird lineages and species has been shown to have begun in a deeper past than formerly thought, although recent analyses from molecular phylogenies also support the much-debated Late Pleistocene model of speciation. Geographical connections between tropical and temperate realms make north-south flyways important drivers of differentiation for many lineages. The histories of differentiation and colonisation of clades, including both resident and long-distance migrants, are discussed in relation to two alternative theories, the ‘southern home theory’ and the ‘northern home theory’. The region-specific characters of the bird faunas and differences between the main temperate forest blocks of the Northern Hemisphere are discussed in light of the hypotheses concerning dispersal processes related with geographical configuration of land masses. Differential dispersal-colonisation rates from tropical regions and subsequent diversification in temperate regions (and vice versa) are also considered. The causes of the observed decline in diversification rates during the Pleistocene are examined from phylogenetic reconstructions of various clades.

Review of the global distribution and hosts of the economically important fish parasitic isopod genus Ceratothoa (Isopoda: Cymothoidae), including the description of Ceratothoa springbok n. sp. from South Africa

Fish parasites from the isopod family Cymothoidae have, in recent years, received increased global attention due to both their ecological and economic importance. This is particularly true for the buccal inhabiting genus Ceratothoa Dana, 1852, whose members have been implicated in negatively impacting the health of both farmed and wild-caught fishes. As research on this group increases, so does our understanding of their host specificity and distribution. The aims of this paper were thus to review the current distribution and host records of Ceratothoa and describe a new species, Ceratothoa springbok n. sp. from South Africa. Including the new species described here, there are currently 25 accepted Ceratothoa spp. known from eight of the 12 marine biogeographical realms of the world. The majority of Cymothoidae species are known to occur in the tropical realms, whereas our analyses show that the greatest diversity of Ceratothoa spp. can be found in temperate realms. These results indicate the possibility that Ceratothoa is more diverse in temperate regions. This review also highlights the low diversity of Ceratothoa from the oceans around both North and South America. Current records indicate that species of Ceratothoa parasitise 108 fish species in 76 genera and 41 families. Eleven Ceratothoa spp. demonstrate host specificity up to host genus or family level. Amongst the hosts, members of the Sparidae are parasitised by 13 species of Ceratothoa, making it the host family with the highest diversity of parasites from this genus. The new species, C. springbok n. sp., also parasitises a sparid and was found in the buccal cavity of the carpenter seabream, Argyrozona argyrozona. This new species, the largest of all recorded Ceratothoa (up to 65 mm) and amongst the largest of all Cymothoidae, is characterised by its truncate and ventrally folded frontal margin, pereonite 1 with medial indentations, the wide anterolateral margins of pereonite 1 with an inwardly produced point, and a well-developed carina on the basis of pereopod 7. A key to the southern African Ceratothoa is provided.

Multiple macroevolutionary routes to becoming a biodiversity hotspot.

Why is species diversity so unevenly distributed across different regions on Earth? Regional differences in biodiversity may stem from differences in rates of speciation and dispersal and colonization times, but these hypotheses have rarely been tested simultaneously at a global scale. Our study reveals the macroevolutionary routes that have generated hotspots of mammal and bird biodiversity by analyzing the tempo and mode of diversification and dispersal within major biogeographic realms. Hotspots in tropical realms had higher rates of speciation, whereas those in temperate realms received more immigrant species from their surrounding regions. We also found that hotspots had higher spatial complexity and energy availability, providing a link between the environment and macroevolutionary history. Our study highlights how assessing differences in macroevolutionary history can help to explain why biodiversity varies so much worldwide.

Translating local benthic community structure to national biogenic reef habitat types

AbstractAimMarine reef habitats are typically defined subjectively. We provide a continental‐scale assessment of dominant reef habitats through analysis of macroalgae and sessile animal taxa at sites distributed around Australia. Relationships between reef habitats and environmental and anthropogenic factors are assessed, and potential changes in the future distribution and persistence of habitats are considered.LocationShallow rocky and coral reefs around the Australian coast.MethodsCover of 38 sessile biota functional groups was recorded in diver‐based surveys using quadrats at 1,299 sites. Classification analyses based on the functional groups were used to identify an unambiguous set of ‘biogenic habitat types’. Random forest and distance‐based linear modelling were used to investigate correlations between these habitats and environmental and anthropogenic variables.ResultsCluster analyses revealed tropical and temperate ‘realms’ in benthic substratum composition, each with finer‐scale habitats: four for the temperate realm (canopy algae, barren, epiphytic algae–understorey and turf) and five for the tropical realm (coral, coral–bacterial mat, turf–coral, calcified algae–coral and foliose algae). Habitats were correlated with different sets of environmental and anthropogenic conditions, with key associations in the temperate realm between mean sea temperature and canopy‐forming algae (negative) and barren habitat (positive). Variation in sea temperature was also an important correlate in the tropical realm.Main conclusionsQuantitative delineation of inshore reef habitats at a continental scale identifies many of the same habitat types traditionally recognized through subjective methods. Importantly, many biogenic reef habitats were closely related to environmental parameters and anthropogenic variables that are predicted to change. Consequently, habitats have differing likelihood of persistence. Structurally complex habitats in the temperate realm are at greater risk than more ‘two‐dimensional’ habitats (e.g., canopy‐forming versus turfing algae). In the tropical realm, offshore and coastal habitats differed greatly, highlighting the importance of large‐scale oceanic conditions in shaping biogenic structure.

Global patterns of terrestrial assemblage turnover within and among land uses

Land use has large effects on the diversity of ecological assemblages. Differences among land uses in the diversity of local assemblages (alpha diversity) have been quantified at a global scale. Effects on the turnover of species composition between locations (beta diversity) are less clear, with previous studies focusing on particular regions or groups of species. Using a global database on the composition of ecological assemblages in different land uses, we test for differences in the between‐site turnover of species composition, within and among land‐use types. Overall, we show a strong impact of land use on assemblage composition. While we find that compositional turnover within land uses does not differ strongly among land uses, human land uses and secondary vegetation in an early stage of recovery are poor at retaining the species that characterise primary vegetation. The dissimilarity of assemblages in human‐impacted habitats compared with primary vegetation was more pronounced in the tropical than temperate realm. An exploratory analysis suggests that this geographic difference might be caused primarily by differences in climate seasonality and in the numbers of species sampled. Taken together the results suggest that, while small‐scale beta diversity within land uses is not strongly impacted by land‐use type, compositional turnover between land uses is substantial. Therefore, land‐use change will lead to profound changes in the structure of ecological assemblages.

Using river discharge to model and deconstruct the latitudinal diversity gradient for fishes of the Western Hemisphere

AbstractAimTo model the species–discharge relationship (SDR) for native freshwater fishes of the Western Hemisphere, to test whether the SDR is itself a function of latitude, and to create a conceptual framework to integrate the SDR with the species–area relationship and the latitudinal diversity gradient.LocationWestern Hemisphere rivers between 70°N and 50°S latitude.MethodsDischarge and fish richness data were compiled for 107 rivers. Ordinary least squares and simultaneous autoregressive models were built for a hemispheric‐scale SDR using one of three discharge (Q) measures: mean annual Q, annual low flow Q or annual high flow Q. Hemispheric‐scale SDR residuals were used to test for distinct low, mid and high latitude groups and to deconstruct the SDR into separate models for each latitudinal group. Structural equation modelling (SEM) was then used to examine the combined effects of Q, river basin area, and latitude on fish richness.ResultsHemispheric‐scale SDRs were significant (P ≤ 0.001) for each discharge measure. Model residuals showed that the SDR differs among tropical, subtropical and temperate realms. All deconstructed SDRs remained significant (P ≤ 0.001) and minimized the residual effect of latitude. The tropical SDR was significantly steeper (non‐overlapping 95% confidence intervals) than the subtropical and temperate SDRs. For both hemispheric‐scale and deconstructed SDRs, annual low flow Q was the best individual predictor of native fish richness. SEM analysis showed that Q may be an integrative measure of climate and physical habitat effects.Main conclusionsA single, hemispheric‐scale SDR will underestimate fish richness in low latitude, tropical rivers and overestimate richness in high latitude, temperate rivers. Deconstructing the SDR into separate tropical, subtropical, and temperate models can account for much of this bias. Deconstructed SDRs also show that fish richness increases much more rapidly per‐unit Q in tropical rivers than in subtropical or temperate rivers. Low flow Q is the strongest correlate of fish richness. And a preliminary, system‐level model suggests that Q may play a central, integrative role in the regulation of freshwater diversity.

Paliurus(Paliureae, Rhamnaceae) from the Miocene of East China and its Macrofossil-based Phylogenetic and Phytogeographical History

The extant genus Paliurus Miller is divided into P. ramosissimus and P. spina-christi groups and is diagnostically characterized by distinctive orbicular-winged fruits with a trilocular (or often bilocular) ovary and basally triveined leaves with a subentire to serrate margin. Here, structurally preserved winged fruits and associated compressed leaves of Paliurus (Paliureae, Rhamnaceae) are reported from the Middle-Upper Miocene Shengxian Formation of Tiantai, Zhejiang, eastern China. The fruits can be identified as Paliurus microcarpa Xiang-Chuan Li sp. nov., the diagnostic characters of external morphology and anatomy of which differ from those of both extant and fossil generic members; the leaves can be designated as Paliurus sp. The species based on winged fruits, P. microcarpa, might represent an ancient intermediate link exclusively known across the P. ramosissimus and P. spina-christi groups, showing a closer affinity to the P. ramosissimus group based on the resemblant smaller fruits with a narrower wing, and to the P. spina-christi group based on the similar wing structure and texture, respectively. Morphological analyses of the present and previous fossil fruit records around the world indicate that diversification of Paliurus had begun in northern transpacific regions by the Late Eocene. The macrofossil records, i.e., fruits and leaves of Paliurus globally when projected on paleoenvironmental maps in view of changing continental positions through time (from Eocene to Miocene) display that the past distribution of the genus was much wider than the present and belongs to a tropical and warm temperate realm of the Northern Hemisphere. Therefore, the modern restricted disjunction in tropical and warm temperate regions of East Asia and South Europe (even eastwards West Asia) might represent glacial refugia for some of the generic ancient lineages to survive severe cold at least since the terminal Pliocene.

Global Diversity of Marine Isopods (Except Asellota and Crustacean Symbionts)

The crustacean order Isopoda (excluding Asellota, crustacean symbionts and freshwater taxa) comprise 3154 described marine species in 379 genera in 37 families according to the WoRMS catalogue. The history of taxonomic discovery over the last two centuries is reviewed. Although a well defined order with the Peracarida, their relationship to other orders is not yet resolved but systematics of the major subordinal taxa is relatively well understood. Isopods range in size from less than 1 mm to Bathynomus giganteus at 365 mm long. They inhabit all marine habitats down to 7280 m depth but with few doubtful exceptions species have restricted biogeographic and bathymetric ranges. Four feeding categories are recognised as much on the basis of anecdotal evidence as hard data: detritus feeders and browsers, carnivores, parasites, and filter feeders. Notable among these are the Cymothooidea that range from predators and scavengers to external blood-sucking micropredators and parasites. Isopods brood 10–1600 eggs depending on individual species. Strong sexual dimorphism is characteristic of several families, notably in Gnathiidae where sessile males live with a harem of females while juvenile praniza stages are ectoparasites of fish. Protandry is known in Cymothoidae and protogyny in Anthuroidea. Some Paranthuridae are neotenous. About half of all coastal, shelf and upper bathyal species have been recorded in the MEOW temperate realms, 40% in tropical regions and the remainder in polar seas. The greatest concentration of temperate species is in Australasia; more have been recorded from temperate North Pacific than the North Atlantic. Of tropical regions, the Central Indo-Pacific is home to more species any other region. Isopods are decidedly asymmetrical latitudinally with 1.35 times as many species in temperate Southern Hemisphere than the temperate North Atlantic and northern Pacific, and almost four times as many Antarctic as Arctic species. More species are known from the bathyal and abyssal Antarctic than Arctic GOODS provinces, and more from the larger Pacific than Atlantic oceans. Two areas with many species known are the New Zealand-Kermadec and the Northern North Pacific provinces. Deep hard substrates such as found on seamounts and the slopes are underrepresented in samples. This, the documented numbers of undescribed species in recent collections and probable cryptic species suggest a large as yet undocumented fauna, potentially an order of magnitude greater than presently known.

Toward representative protection of the world's coasts and oceans—progress, gaps, and opportunities

AbstractMarine conservation lags behind terrestrial in the establishment of protected areas. This was recognized by the Convention on Biological Diversity, whose members, in 2004, agreed to establish “comprehensive, effectively managed, and ecologically representative” systems of marine protected areas (MPAs) by 2012. Halfway toward this target date, we look at the coverage of the world's 5045 MPAs from a biogeographic perspective. Only 4.09% of continental shelf areas are incorporated within MPAs, although coverage rises to 12.1% in a narrow coastal belt. Approximately half of all marine ecoregions have less than 1% MPA coverage across the shelf, but this is highly variable, and (8%) of ecoregions have >30% protection. Protection is greatest in the tropical realms, while temperate realms remain poorly represented. Given that that many sites lack effective management, even these low estimates of coverage are an optimistic measure of the extent of effective marine conservation.

Shallow-marine ostracode faunas around the Eocene/Oligocene boundary in the northwestern Kyushu, southwestern Japan

Middle Eocene–early Oligocene ostracode faunal changes in northwestern Kyushu of southwestern Japan are identified in this study. Ostracodes occur from shelf deposits of five formations: the middle Eocene Okinoshima, the upper Eocene Funazu, the uppermost Eocene–lowermost Oligocene Kishima, the lowermost Oligocene Itanoura, and the lower Oligocene Waita Formations. The middle Eocene–earliest Oligocene ostracodes were characterized by warm-water genera, indicating tropical, subtropical and Tethyan genera, whereas the late early Oligocene ostracodes do not include warm-water taxa, consisting of temperate realm genera. The middle Eocene–earliest Oligocene ostracodes do not include remarkable changes of species composition, in contract with equatorial Pacific radiolarians and West Coast USA molluscs. Ostracodes suggest that distinct climatic cooling did not occur in the southwestern Japan during the middle Eocene–earliest Oligocene.

The Cretaceous of the Elbe valley in Saxony (Germany) - a review

In Central Europe one of the most important interchanges between the North Temperate Realm and the Tethyan Realm took place during the Cenomanian along the course of the Elbe Valley Geosuture that separates the Erzgebirges block (part of the Mid European island during the Cretaceous) from the Lusatian block (West Sudetic island: Scupin, 1937). Strata of the Lower Cretaceous and the basal portion of Lower Cenomanian are absent in the Elbe Valley Geosuture but a marine transgression in a NW-SE direction occupied a portion of this tract during the late Early Cenomanian and a second incursion from SE to NW occurred during the Late Cenomanian.

Jurassic evolution of Southern Hemisphere marine palaeobiogeographic units based on benthonic bivalves

The distribution of benthonic Jurassic bivalve genera in the Southern Hemisphere is analysed here. For this region, palaeobiogeographic units (biochoremas) are quantitatively characterized according to their biologic contents (mainly levels of endemism). Their evolution through time is followed from the latest Triassic to the earliest Cretaceous. The Tethyan Realm is undoubtedly the most mature and persistent through time, with three subordinate units: an Australian unit restricted to the Late Triassic, a North Andean unit, which appears sporadically as an endemic centre, and an East African unit which is recognisable from Bajocian times onwards. From Late Triassic times, a South Pacific Realm has been recognised, with a Maorian Province mostly based on the distribution of monotoid genera. A South Andean unit is also recognisable through most of the Jurassic, and its reference either to the South Pacific unit or to the Tethyan Realm is a matter of debate. Being a transitional biogeographic setting between Tethyan and South Pacific first-order units, it is included in the South Pacific unit due to the common presence of antitropical (didemic) genera. The East African unit is included within the Tethyan Realm during the Jurassic, but during Early Cretaceous times, it splits into two units, one of which was regarded as part of the “South Temperate Realm” by Kauffman. The rank of all these units changed with time. Throughout the Jurassic, the ecotone between South Pacific and Tethyan palaeobiogeographic units fluctuated in position with time. The approximate latitudinal location of the ecotonal boundary area and its shift through time are recognised on the basis of faunal composition along the Andean region.

Are Mesozoic wood growth rings climate-induced?

Growth rings of Mesozoic fossil woods have often been used for paleoclimatological inferences. Most of the studies, however, rest upon uniformitarian deductions based on the observation of conifers from the present boreal temperate realm, whereas warm climates dominated during the Mesozoic. We propose a new approach, based on the study of the distribution of growth ring types among 643 samples from the Jurassic-Cretaceous interval. A clear picture emerges from analysis, consistent with what is known of Mesozoic climates from other sources. Woods with no rings are encountered in a wide latitudinal zone, extending up to 75°N and 65°S during the Late Cretaceous. Woods with well-developed latewood do not occur at low latitude and disappeared from the Northern Hemisphere during the Late Cretaceous. Our data set also shows that the taxonomic distribution of growth ring types is not regular. Among the genera encountered, 40% can build only one type of ring. The genus Agathoxylon never displays thick latewood, although it ranges from 75°S to 70°N. This demonstrates that growth ring studies must include a taxonomic analysis.

Subtropical carbonates in a temperate realm; modern sediments on the Southwest Australian shelf

The southwestern continental margin of Australia (19 degrees S-22 degrees S) in the western Indian Ocean is transitional between cool-water and warm-water carbonate realms. It comprises the incipiently rimmed, flat-topped, steep-fronted Rottnest Shelf in the south, the uniform subtropical starved Carnarvon Ramp off Shark Bay, and the Ningaloo fringing reef in the north. The margin is strongly influenced by the poleward-flowing, warm, nutrient-poor Leeuwin Current, which promotes overall downwelling and strong summer equatorward-blowing winds, which generate local seasonal upwelling. The structurally quiescent northern part of the Rottnest Shelf, with minimum accommodation, is characterized by luxuriant stands of sea-grasses and macrophytes growing on coralline-encrusted hardgrounds and rooted in sediments rich in coralline algae and larger, symbiont-bearing foraminifers together with abundant cool-water elements such as bryozoans, molluscs, and small foraminifers. Halimeda is poorly calcified and does not contribute to the sediment. Azooxanthellate corals, although present, are not common. Such a sediment pattern has many analogs in the geologic record, especially the early Cenozoic. The incipient rim is a morphologically complex linear ridge system interpreted to be a buried mid-Pleistocene barrier reef or beach-dune complex. The northern part of the ridge complex is capped by the Houtman Abrolhos reef platforms. Subphotic sediments on the deep, outer shelf and upper slope, affected by seasonal upwelling, are typical cool-water, poorly sorted, bryozoan-dominated deposits rich in small foraminifers and sponge spicules. The inner part of the more structurally active Carnarvon Ramp ranges from steep eolianite cliffs to hypersaline environments of Shark Bay to the Ningaloo fringing reef. Mid-ramp sediment, especially off Shark Bay, is mostly relict or stranded and foraminifer-dominated sand with abundant Mg-calcite-cemented intraclasts. These sediments, accumulating on a relatively barren seafloor, likely represent attenuated carbonate production brought about by downwelling and episodic incursions of saline, Shark Bay-derived waters onto the ramp. The outer ramp is either planktic foraminiferal sand, sorted by strong bottom currents, or spiculitic mud. Such sedimentation patterns should typify the western margins of large ocean basins during those periods in geologic history when circumglobal equatorial circulation was active, and equatorial gateways narrow, in contrast to eras of supercontinents, when cool-water carbonate sedimentation and upwelling prevailed in similar settings. Furthermore, because low-latitude trade winds relax during glacial epochs and the cool-water, upwelling belt moves equatorward into otherwise tropical realms, temperate and subtropical sedimentation patterns in these regions should oscillate at the 100 ky scale in the stratigraphic record.

Subtropical Carbonates in a Temperate Realm: Modern Sediments on the Southwest Australian Shelf

Subtropical Carbonates in a Temperate Realm: Modern Sediments on the Southwest Australian Shelf

Introduction to the Symposium: Responses of Terrestrial Arthropods to Variation in the Thermal and Hydric Environment: Molecular, Organismal, and Evolutionary Approaches

CONTEXT FOR THE SYMPOSIUM Within the temperate realm, temperature and water availability are the dominant environmental parameters that determine species distributions (Gates, 1993). The physiological effects of thermal and water variability are interactive, because temperature strongly affects water loss, and evaporative water loss is often a critical mechanism for preventing overheating. Understanding how organisms respond on short and evolutionary time scales to variation in the thermal and hydric environment is therefore a central question of of modern biology. These issues have recently become more urgent, as societal decisions require predictive models of the ecological effects of variation in global climate (Kareiva, et al., 1993). Terrestrial arthropods provide particularly valuable models for the study of the biological effects of thermal and hydric variability due to their ecological importance, species diversity, ease of rearing, and short generation times. However, use of terrestrial arthropods as model organisms for evolutionary and environmental studies ultimately depends on a solid understanding of their cellular and organismal physiology. Traditionally our understanding of the physiology of invertebrates has lagged well behind our knowledge of vertebrates, partly due to the focus of research on biomedicine, and partly due to technical limitations imposed by small body sizes. Recent advances in molecular biology, computer, and micro-analytical technologies have overcome many of these technical limitations, and we are entering an era of rapid advances in our understanding of the genetics, cell biology, and physiology of terrestrial arthropods. At the same time, ecologists and evolutionary biologists are conducting rigorous empirical studies of the fitness consequences of environmental variation and organismal responses. Together, these advances are providing information of basic importance to medicine, agriculture, ecology, and evolutionary biology.

The Late Cretaceous belemnite family Belemnitellidae: Taxonomy and evolutionary history

The Late Cretaceous belemnite family Belemnitellidae Pavlow, 1914 occurs only in the Northern Hemisphere and includes nine genera and two subgenera: Praeactinocamax Naidin, 1964b, Actinocamax Miller, 1823, Belemnocamax Crick, 1910, GonioteuthisBayle, lS7S,BelemnellocamaxNaidin, 1964b,Goniocamax Naidin, 1964b, Belemnitella d'Orbigny, 1840, Belemnella (Belemnella) Nowak, 1913, Belemnella (Pachybelemnella) Schulz, 1979, Belemnella (Neobelemnella) Naidin, 1975 and Fusiteuthis Kongiel, 1962. The latter is most likely a nomen dubium. Diagnoses of the genera and subgenera are provided. The origin of the family is poorly known. The number of genera and subgenera, fluctuated during the Late Cretaceous. It was one to two in the Cenomanian, increased gradually to a maximum of six in the Early Santonian, decreased gradually to one during most of the Late Campanian and increased to two or possibly three in the Maastrichtian. The belemnitellids occur in the North European and North American palaeobiogeographical Provinces of the North Temperate Realm, in additon to the northern European margin of the Tethyan Realm. The centre of evolution lay in the North European Province and all known genera and subgenera occur there. Species of five genera and two subgenera occur on the northern European margin of the Tethyan Realm and the majority of these are conspecific with species from the North European Province. Species of essentially two genera occur in the North American Province and these are endemic, with a few exceptions.

Additional Late Cretaceous belemnitellids from the Corbières, French Pyrenees and ammonite biostratigraphy of the Santonian

Two new, nearly complete specimens of Belemnellocamax ex gr. grossouvrei are described from the base of the Santonian Sougraigne Blue Marls Formation of the Corbières in the French Pyrenees. This group is rare, but widely distributed in the North European palaeobiogeographic Province of the North Temperate Realm and occurs also in the northernmost part of the Tethyan Realm. In the Corbières it is now recorded from the base and top of the Sougraigne Blue Marls, which is assigned, on the basis of revised ammonite data, to the Placenticeras polyopsis and Texanites gallicus Concurrent-range-zone. This zone embraces most or all of the Santonian in the Corbières.

Marine ostracode provincialism in the late cretaceous of the tethyan realm and the Austral province

A synthetic analysis based on previous and new data allows the recognition of four main palaeobiogeographic units (palaeobioprovinces) for the Late Cretaceous of the Tethyan Realm and Austral Province of the South Temperate Realm: South European, North-Central American, Afro-Arabian, and Austral Bioprovinces. Another unit, the Dinaro-Hellenic Subprovince is located between the South European and the Afro-Arabian bioprovinces. Special emphasis is given to the spatial and temporal distribution of ostracode assemblages (at the specific level) and selected “key genera” within several geographic zones, from the Tethys (North- Central America, southern Europe, northern Africa, and the Middle East) to eastern Africa, India, South Africa, and Australia. Several factors are responsible for these palaeobiogeographic distributions (provincialism) and their evolution: the position and extension of continental margins, oceanic surface current patterns, paleobathymetry, eustatic sea-level changes, paleolatitudes, and their influence on paleoclimates. Other parameters are the biology, physiology, and ecology of the ostracodes. Therefore, ostracode provincialism has a high potential for further paleogeographic inferences, such as global tectonic reconstructions.