The European Tertiary Neritiliidae (Mollusca, Gastropoda, Neritopsina): indicators of tropical submarine cave environments and freshwater faunas

The oldest freshwater neritiliid, Neritilia bisinuata , is described from the Middle Eocene of the Loire Basin. Another European species, N. neritinoides , ranging from the Lower Oligocene to Lower Miocene (Upper Burdigalian) is recognized; its habitat appears to have been freshwater, but very close to the sea. Two new marine neritiliid species from the Aquitaine Basin are described: Bourdieria favia sp. nov. from the Upper Oligocene and Pisulinella aucoini  sp. nov. from the Lower Miocene. A third undescribed species from the Lower Miocene is referred to the same family and related to Pisulinella . The Oligocene species has a strong spiral sculpture, a character completely absent in previously known neritiliid species. The genus Agapilia , founded on juvenile N. neritinoides and adult Vitta picta , appears to be a junior synonym of the genus Vitta. The associated occurrence of shells of the families Neritiliidae, Neritopsidae and Pickworthiidae (well-known inhabitants of Indo-West Pacific submarine caves) at Peyrère suggest the first occurrence of a characteristic assemblage of dark submarine caves during the Oligocene. Both factorial analysis and relative abundance show that at Peyrère these families are associated with other cryptic fossils (various gastropods, bivalves, Brachiopoda, corals, Annelida). However, there are indications of other submarine cave assemblages in various Cenozoic deposits from the Palaeocene to the middle Miocene.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 447–467.     

Genetic exchange between anchialine cave populations by means of larval dispersal: the case of a new gastropod species Neritilia cavernicola

Despite being limited to caves, many anchialine taxa have disjunct insular distributions, which raises questions about their origins and colonization history. This study deals with the new gastropod Neritilia cavernicola sp. n. (Neritopsina: Neritiliidae) from anchialine caves on two islands in the Philippines that are separated by the deep Bohol Strait and situated 200 km apart along the coastline of Cebu Island. Neritilia cavernicola is an obligate stygobiont and most closely resembles Neritilia littoralis , which lives in interstitial waters of the Nansei-shoto Islands, Japan. Its eggs and larval shells are identical to those of other Neritilia species, despite their different adult habitats. This suggests a marine planktotrophic phase (as occurs in amphidromous riverine species of Neritilia ), and consequent migration between islands via ocean currents. Here we present the first genetic structure for anchialine cave organisms; comparisons of 1276 bp sequences from mitochondrial cytochrome oxidase I show no evidence of genetic isolation between the islands. All individuals evidently are part of a panmictic population and the low vagility of adults and their seemingly isolated cave habitats do not limit gene flow in N. cavernicola . This migration model, based on marine larval dispersal, may be widely applicable to anchialine stygobites with insular distributions, as many such organisms (including shrimps, crabs and fishes) are phylogenetically allied to amphidromous species.     

The dispersal and colonisation behaviour of the marine polychaete <Emphasis Type="Italic">Nereis diversicolor</Emphasis> (O. F. Müller) in south-east England

Recent submarine caves are inhabited by endemic faunas adapted to oligotrophism, darkness and a tranquil environment. Many of their representatives are archaic types of animals resembling fossils from very early times in evolution. This article compares fossil fauna from Jurassic neptunian dykes (originally sea bed clefts) from the Western Carpathians with the Recent cave-dwelling fauna. The ostracods Pokornyopsis feifeli are particularly important. In the Western Carpathians, these were exclusively found in the Middle/Late Jurassic fissure fillings, but in the non-Tethyan Germanic Jurassic this species was found in deep-marine claystones. They are phylogenetic forerunners of the recent genus Danielopolina inhabiting both anchialine caves and deep seas. This indicates a Jurassic migration of deep-marine fauna to cryptic habitats. Other examples of cryptic communities include the Upper Jurassic cavity-dwelling fauna dominated by serpulids and scleractinian corals. Associated suspension feeders include thecideidine brachiopods, oysters, bryozoans, sponges, crinoids and sessile foraminifers. Serpulid-dominated bioconstructions have recent analogies in the Mediterranean and Carribean seas. Different type of dyke communities represent the Late Jurassic fauna of small sized ammonites which originated from both Tethyan and Boreal paleobioprovinces. It has not been established whether these amonites were juvenile, dwarfed specimens adapted to limited cave space or size-sorted adult specimens.     

Permian–Triassic Osteichthyes (bony fishes): diversity dynamics and body size evolution

The Permian and Triassic were key time intervals in the history of life on Earth. Both periods are marked by a series of biotic crises including the most catastrophic of such events, the end‐Permian mass extinction, which eventually led to a major turnover from typical Palaeozoic faunas and floras to those that are emblematic for the Mesozoic and Cenozoic. Here we review patterns in Permian–Triassic bony fishes, a group whose evolutionary dynamics are understudied. Based on data from primary literature, we analyse changes in their taxonomic diversity and body size (as a proxy for trophic position) and explore their response to Permian–Triassic events. Diversity and body size are investigated separately for different groups of Osteichthyes (Dipnoi, Actinistia, ‘Palaeopterygii’, ‘Subholostei’, Holostei, Teleosteomorpha), within the marine and freshwater realms and on a global scale (total diversity) as well as across palaeolatitudinal belts. Diversity is also measured for different palaeogeographical provinces. Our results suggest a general trend from low osteichthyan diversity in the Permian to higher levels in the Triassic. Diversity dynamics in the Permian are marked by a decline in freshwater taxa during the Cisuralian. An extinction event during the end‐Guadalupian crisis is not evident from our data, but ‘palaeopterygians’ experienced a significant body size increase across the Guadalupian–Lopingian boundary and these fishes upheld their position as large, top predators from the Late Permian to the Late Triassic. Elevated turnover rates are documented at the Permian–Triassic boundary, and two distinct diversification events are noted in the wake of this biotic crisis, a first one during the Early Triassic (dipnoans, actinistians, ‘palaeopterygians’, ‘subholosteans’) and a second one during the Middle Triassic (‘subholosteans’, neopterygians). The origination of new, small taxa predominantly among these groups during the Middle Triassic event caused a significant reduction in osteichthyan body size. Neopterygii, the clade that encompasses the vast majority of extant fishes, underwent another diversification phase in the Late Triassic. The Triassic radiation of Osteichthyes, predominantly of Actinopterygii, which only occurred after severe extinctions among Chondrichthyes during the Middle–Late Permian, resulted in a profound change within global fish communities, from chondrichthyan‐rich faunas of the Permo‐Carboniferous to typical Mesozoic and Cenozoic associations dominated by actinopterygians. This turnover was not sudden but followed a stepwise pattern, with leaps during extinction events.     

Penguin heat-retention structures evolved in a greenhouse Earth

Penguins (Sphenisciformes) inhabit some of the most extreme environments on Earth. The 60+ Myr fossil record of penguins spans an interval that witnessed dramatic shifts in Cenozoic ocean temperatures and currents, indicating a long interplay between penguin evolution and environmental change. Perhaps the most celebrated example is the successful Late Cenozoic invasion of glacial environments by crown clade penguins. A major adaptation that allows penguins to forage in cold water is the humeral arterial plexus, a vascular counter-current heat exchanger (CCHE) that limits heat loss through the flipper. Fossil evidence reveals that the humeral plexus arose at least 49 Ma during a 'Greenhouse Earth' interval. The evolution of the CCHE is therefore unrelated to global cooling or development of polar ice sheets, but probably represents an adaptation to foraging in subsurface waters at temperate latitudes. As global climate cooled, the CCHE was key to invasion of thermally more demanding environments associated with Antarctic ice sheets.     

The Crocuta crocuta spelaea (Goldfuss 1823) population and its prey from the Late Pleistocene Teufelskammer Cave hyena den besides the famous Paleolithic Neandertal Cave (NRW,NW Germany)

Remains from at least seven individuals of the Late Pleistocene Ice Age spotted hyena Crocuta crocuta spelaea (Goldfuss, 1823) from the Teufelskammer Cave in the Neandertal valley (North Rhine-Westphalia, northwest Germany) are described. The small cave was a well-frequented hyena den of the Early to Middle Late Pleistocene which was only 100 m from the famous small Feldhofer Cave, where the first Neandertal human skeleton was found. The high amount of hyena bone material (37%) and its strongly chewed and incomplete prey remains of the mixed mammoth steppe and boreal forest megafauna prove one more of 11 recently known hyena den caves in the Rhenish Massif. Hyenas and cave bears have used the cave, but Neandertal humans lived possibly not at the same time in the same valley. Although hyenas occupied mainly the smaller caves such as the Teufelskammer Cave, humans preferred large portal cave entrances such as in the Neandertal valley with the Small Feldhofer Cave.     

A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China

The number of Late Pleistocene hominin species and the timing of their extinction are issues receiving renewed attention following genomic evidence for interbreeding between the ancestors of some living humans and archaic taxa. Yet, major gaps in the fossil record and uncertainties surrounding the age of key fossils have meant that these questions remain poorly understood. Here we describe and compare a highly unusual femur from Late Pleistocene sediments at Maludong (Yunnan), Southwest China, recovered along with cranial remains that exhibit a mixture of anatomically modern human and archaic traits. Our studies show that the Maludong femur has affinities to archaic hominins, especially Lower Pleistocene femora. However, the scarcity of later Middle and Late Pleistocene archaic remains in East Asia makes an assessment of systematically relevant character states difficult, warranting caution in assigning the specimen to a species at this time. The Maludong fossil probably samples an archaic population that survived until around 14,000 years ago in the biogeographically complex region of Southwest China.     

江苏泗洪北部两个晚新生代的地层剖面及所含脊椎动物化石

本文描述了泗洪北部两个晚新生代的地层剖面及其所含脊椎动物,确立了泗洪北部广泛分布的砂砾层的层序和时代.含 "Diceratherium" cf. minus 的重岗山的砂砾层的时代为晚中新世早期,含有 Proboscidipparion、Stegodon orientalis 和 Palaeoloxodon naumanni 等化石的归仁砂砾层的时代则为早更新世.     

Tethyan changes shaped aquatic diversification

The Tethys Ocean existed between the continents of Gondwana and Laurasia from the Triassic to the Pliocene. Analyses of multiple biogeographic and phylogenetic histories reveal that the subsequent breakup of the Tethys greatly influenced the distributions of many species. The ancestral Tethyan realm broke into five biogeographic provinces, including the present‐day East Pacific, West Atlantic, East Atlantic, Mediterranean Sea, and Indo‐West Pacific. Palaeogeographic maps illustrate the Mesozoic Atlantic opening, the Cenozoic closure of the Tethys, the Messinian Salinity Crisis, the mid‐Miocene closure of the Central American Seaway, and Quaternary geological changes. Further, we consider Cenozoic sea‐level changes and the formation of freshwater habitats. These reconstructions allow assessment of patterns of aquatic diversification for marine and freshwater animals, and comparison of vicariance and dispersal processes. Estimated divergence times indicate that fragmentation of the Tethys was responsible for the vicariant speciation of aquatic animals because these dates are consistent with associated tectonic events. The opening of the Atlantic Ocean during the Cretaceous is responsible for the earliest isolation between the West and East Atlantic. The mid‐Miocene closure of the Tethys, which blocked global equatorial currents, appears to have isolated the Atlantic/Mediterranean Sea and Indo‐West Pacific. Finally, formation of the Isthmus of Panama isolated East Pacific and West Atlantic marine organisms. Dispersals related to the Messinian Salinity Crisis and Quaternary sea‐level changes influenced population structuring. Tethyan changes affected marine habitats, created new freshwater habitats, inland caves and ancient lakes along the Alps and Himalayas, and influenced anchialine caves at the edge of the ancient sea. The extensive new habitats provided opportunities for colonisation and rapid diversification. Future work should focus on testing the biological impact of the series of Tethyan changes.     

Ocean basin and depth variability of oxygen isotopes in cenozoic benthic foraminifera

One of the longest, most detailed quantitative records of oceanographic change in the Cenozoic is that provided by oxygen isotope measurements made on the tests of foraminifera. As indicated by measurements on benthic foraminifera, the deep waters of the world ocean have undergone an overall cooling of about 10°C in the Cenozoic. This change has been neither monotonic nor gradual. Rather, it is evidenced by a few, relatively rapid increases in the ¹³O content of the benthic shells. These “steps” in the isotopic record have been associated with major evolutionary changes in the mean state of the deep ocean. The variance around this mean state has also changed through the Cenozoic. From relatively high variance in the Middle Eocene, the oceans showed low variance in the Late Eocene and Oligocene. In the Miocene the variance of the isotopic measurement again increased, reaching a maximum of short duration in the Middle Miocene. This maximum as well as that which occurred during the Late Pliocene and Quaternary, may be attributable to fluctuations in the isotopic composition of the oceans caused by growth and decay of large ice sheets.In the Late Miocene the benthic oxygen isotopes in Atlantic sites less than 3000 m deep have a higher variance than sites at similar depths in the Pacific and Indian Oceans. It is thought that this high variance results from long-term changes in the importance of the cool and salty North Atlantic Deep Water relative to that of the warmer and less saline Antarctic Intermediate Water at Atlantic sites between 1000 m and 3000 m water depth. Such significant differences in benthic isotopic variance between the ocean basins have been demonstrated only in post-Middle Miocene intervals.     

新生代全球变化与中国古植物区系的演变

新生代是地质历史最年轻的一个时代 ,当时全球板块运动和岩浆活动强烈而频繁 ,中生代开始的大陆漂移活动继续进行 ,并于早第三纪末开始喜马拉雅运动 ,古地中海逐渐封闭 ,经过一系列的板块碰撞和洋底扩张 ,晚第三纪时地壳构造的基本轮廓和古地理面貌逐渐接近现代。受地壳运动的控制 ,全球新生代气候波动明显 ,早第三纪总体比较温暖 ,晚第三纪气候发生明显分异 ,气温显著下降 ,第三纪末期开始有冰川活动 ,一直持续到更新世末期 ,期间发生多次冰期和间冰期 ,全新世气候逐渐转暖。受上述全球变化的影响 ,我国新生代植物区系纵向演变和横向分异明显 ,早第三纪植物区系主要是纬向分带 ,从古新世到渐新世 ,我国植物区系主要分为北方区和南方区 ;晚第三纪初 ,由于喜马拉雅运动使青藏高原及东部的横断山脉地区持续抬升 ,逐渐形成独立的高原植物区。总体来说 ,晚第三纪植物区系和植被类型逐渐接近现代。第四纪由于青藏高原继续强烈抬升 ,激发了东亚季风 ,使我国的植物区系经向分带更加明显 ,植物区系和植被类型与现代已基本一致 ,到了全新世晚期 ,植物区系的演变除了受全球变化的影响外 ,人类活动的作用也越来越明显     

Evolution of bone microanatomy of the tetrapod tibia and its use in palaeobiological inference

Bone microanatomy appears to track changes in various physiological or ecological properties of the individual or the taxon. Analyses of sections of the tibia of 99 taxa show a highly significant (P 相似文献   

The Xujiayao 14 Mandibular Ramus and Pleistocene Homo Mandibular Variation

The earlier Late Pleistocene mandibular ramus from Xujiayao (northern China) preserves traits that vary distributionally among western Old World Pleistocene Homo samples and between Early/Middle Pleistocene archaic humans and Late Pleistocene modern humans in eastern Eurasia. Xujiayao 14 presents a lateral mandibular notch crest, an open mandibular foramen, a wide ramus, an asymmetrical mandibular notch, an enlarged superior medial pterygoid tubercle, (probably) a retromolar space, and gonial eversion, as well as an unusual depression in the planum triangulare. The first two traits appear ancestral for Later Pleistocene and recent Homo and are dominant among modern humans. The second two traits largely separate Xujiayao 14 and archaic Homo from modern humans. The next two traits are found in the highest frequency among the Neandertals, although gonial eversion contrasts with Late Pleistocene Neandertals. Xujiayao 14, in the context of Pleistocene and recent Homo samples and the other Xujiayao human remains, therefore provides a morphological mosaic, highlighting regional variation through the Pleistocene.     

Specialized shell-breaking crab claws in Cretaceous seas

Here we report on a large brachyuran crab species from the Late Cretaceous of Mexico that has claws indicative of highly specialized shell-breaking behaviour. This crab possessed dimorphic claws (the right larger than the left), armed with several broad teeth, including a curved tooth structure found at the base of the movable finger of the right claw. The curved tooth is similar to the one observed on claws of many living durophagous crabs that use it as a weapon to peel, crush or chip the edges of hard-shelled prey, particularly molluscs. These morphological traits suggest that specialized shell-breaking crab predators had evolved during the Cretaceous, which contradicts previous findings supporting an Early Cenozoic origin for specialized shell crushers within the brachyuran clade.     

Early Cenozoic Differentiation of Polar Marine Faunas

The widespread assumption that the origin of polar marine faunas is linked to the onset of major global cooling in the Late Eocene – Early Oligocene is being increasingly challenged. The Antarctic fossil record in particular is suggesting that some modern Southern Ocean taxa may have Early Eocene or even Paleocene origins, i.e. well within the Early Cenozoic greenhouse world. A global analysis of one of the largest marine clades at the present day, the Neogastropoda, indicates that not only is there a decrease in the number of species from the tropics to the poles but also a decrease in the evenness of their distribution. A small number of neogastropod families with predominantly generalist trophic strategies at both poles points to the key role of seasonality in structuring the highest latitude marine assemblages. A distinct latitudinal gradient in seasonality is temperature-invariant and would have operated through periods of global warmth such as the Early Cenozoic. To test this concept a second global analysis was undertaken of earliest Cenozoic (Paleocene) neogastropods and this does indeed show a certain degree of faunal differentiation at both poles. The Buccinidae, s.l. is especially well developed at this time, and this is a major generalist taxon at the present day. There is an element of asymmetry associated with this development of Paleocene polar faunas in that those in the south are more strongly differentiated than their northern counterparts; this can in turn be linked to the already substantial isolation of the southern high latitudes. The key role of seasonality in the formation of polar marine faunas has implications for contemporary ecosystem structure and stability.     

东海陆架西南部台北坳陷新近纪孢粉植物群演替

对东海陆架西南部台北坳陷13口钻井孢粉分析表明,本地区新近纪植物群经历了3个发展阶段,即：1)早中新世早期松科花粉优势期;2)早、中中新世阿丁枫科花粉繁盛期;3)晚中新世至早上新世草本被子植物发展期。各时期孢粉植物群在横向上几乎没有大的区别,表明新近纪整个坳陷内构造与沉积环境及其变迁具有很好的一致性。植物群演替反映古气候从早中新世早期的湿润温凉到早、中中新世的暖湿,最后(晚中新世至早上新世)又趋温凉的变化历程。     

临夏盆地的新生代地层及其哺乳动物化石证据

临夏盆地的新生代地层相当发育 ,保存了从渐新世至全新世的连续沉积序列。更为重要的是 ,这些沉积物中含有丰富的哺乳动物化石 ,为划分和对比临夏盆地的新生代地层提供了可靠的证据。然而 ,此前关于这个盆地地层层序和时代的认识有许多矛盾之处 ,地层命名繁复 ,化石证据混乱。近年来我们对临夏盆地的野外考察已理清了沉积序列 ,并在充分的哺乳动物化石证据的基础上重新厘定了各个岩石地层单位所对应的地质时代。临夏盆地的新生代哺乳动物化石以晚渐新世的巨犀动物群、中中新世的铲齿象动物群、晚中新世的三趾马动物群和早更新世的真马动物群最为丰富。     

Environmental significance of the potential for mer(Tn21)-mediated reduction of Hg2+ to Hg0 in natural waters.

The role of mer(Tn21) in the adaptation of aquatic microbial communities to Hg2+ was investigated. Elemental mercury was the sole product of Hg2+ volatilization by freshwater and saline water microbial communities. Bacterial activity was responsible for biotransformation because most microeucaryotes did not survive the exposure conditions, and removal of larger microbes (greater than 1 micromole) from adapted communities did not significantly (P greater than 0.01) reduce Hg2+ volatilization rates. DNA sequences homologous to mer(Tn21) were found in 50% of Hg2+-resistant bacterial strains representing two freshwater communities, but in only 12% of strains representing two saline communities (the difference was highly significant; P less than 0.001). Thus, mer(Tn21) played a significant role in Hg2+ resistance among strains isolated from fresh waters, in which microbial activity had a limited role in Hg2+ volatilization. In saline water environments in which microbially mediated volatilization was the major mechanism of Hg2+ loss, other bacterial genes coded for this biotransformation.     

Genetic divergence in Greek populations of the genus Leuciscus and its evolutionary and biogeographical implications

In 23 populations of Greek Leuciscus ( Squalius ), the percentage of polymorphic allozyme loci ranged between 0·034 and 0·379 (P=0·19) and expected heterozygosity was 0·011–0·166 (H_e=0·067). Current taxonomy is confusing and does not correspond to genetic data that support the presence in Greece of at least seven different species: L. cephalus , L. peloponnensis , L. prespensis , L. moreoticus , L. borysthenicus , L. keadicus and Leuciscus sp. from Euboea Island. The maximum Nei modified genetic distance was found among L. keadicus and the rest of subgenus Squalius populations D * Nei=0·446–0·705). Accepting the molecular clock hypothesis, speciation for the genus Leuciscus in Greece must have occurred during the Cenozoic period (between the Middle Miocene and the Later Pliocene). The two main biogeographical events causing speciation on mainland Greece were the Uplift of the Pindic cordillera and the isolation of the southern part of Peloponnesus. The faunistic composition of the lakes studied, in which new taxa are reconsidered, suggests the same faunistic origin in the Early Pliocene for Lakes Prespa and Stymphalia and a younger one in the Late Pliocene for Lake Trichonis. Euboea Island was not a zoogeographical unit during the Cenozoic. The isolation of all the freshwater fish fauna of Euboea has occurred since the Pliocene. The biogeographical model proposed here differs from classical hypotheses in considering of lesser importance the dispersion of L. cephalus on the Greek mainland during the Neogene and Quaternary.     

Phanerozoic changes in the high-rank suprageneric diversity structure of brachiopods: Linear and non-linear effects

Phanerozoic evolution of brachiopods produced many linear (established by a comparison of successive geologic time units) and non-linear (established by a comparison of non-successive geologic time units) effects, which can be examined quantitatively by using the similarity coefficients (Czekanowski's Quantified Coefficient and Gower Index) and correlation tools. The high-rank suprageneric diversity structure accounts for a number of superfamilies in each of 26 orders for every epoch of geological time. The intensity of turnovers in this structure was generally low during the entire Phanerozoic. It was slightly stronger during the Early Paleozoic, but close to zero during the Cenozoic, when the high-rank suprageneric diversity structure of brachiopods stabilized finally. Significant turnovers took place at the Middle Cambrian–Early Ordovician, the Late Ordovician–Early Silurian, the Late Silurian–Early Devonian, the Middle Devonian–Mississippian, and the Permian–Triassic transitions. Influences of mass extinctions, both major like those End Ordovician or Permian/Triassic and minor like Early Jurassic or Jurassic/Cretaceous, on the high-rank suprageneric diversity structure of brachiopods is registered. The strongest was the consequences of the Permian/Triassic catastrophe, which perhaps even reset the brachiopod evolution. No evident direct relationships are established between intensity of turnovers and eustatic fluctuations. However, the changes in the diversity structure recorded with the Gower Index provide evidence that eustatic lowstands were more favorable for intensification in these changes.