Hasil untuk "Paleontology"

Zixiaocheng Wang, Yan Zheng, Alexandr P. Rasnitsyn et al.

Two new species assigned to the genus <i>Myanmarina</i> of the family Myanmarinidae are described and figured from male specimens preserved in Upper Cretaceous ambers from the Hukawng Valley of northern Myanmar. <i>Myanmarina simplex</i> sp. nov. can be distinguished by a small head, 13-segmented antennae, the first flagellomere equal to the second one in length and protibiae with a bifurcated spur. <i>Myanmarina grandis</i> sp. nov. is established based on a large head, 11-segmented antennae, the first flagellomere shorter than the second one and all tibiae with a spur and dorso-apical tooth. In addition, the key to known species of <i>Myanmarina</i> was updated.

Giulia Bosio, Alberto Collareta, Matteo Pedini et al.

The Miocene Pisco Formation (East Pisco Basin, Peru) is renowned for its abundant, well-preserved fossils of marine vertebrates, representing one of the most spectacular and complete records of Neogene marine vertebrates worldwide. Here, we present a geological map at 1:10,000 scale investigating the spatial and temporal distribution of fossil vertebrates at Cerros Cadena de los Zanjones, in the Ica River Valley. Stratigraphic and paleontological analyses reveal the widespread occurrence of marine vertebrate remains in the Tortonian (10.0–8.6 Ma) P1 and Tortonian – Messinian (8.4–6.9 Ma) P2 sequences. These include 91 specimens preserved as bony elements, including cetaceans (both Odontoceti and Mysticeti), seals (Pinnipedia) and bony fishes (Osteichthyes). Elasmobranchs, including Carcharhiniformes, Lamniformes and Myliobatiformes, are represented by some 300 teeth. The P1-P2 passage is marked by faunal novelties such as the first appearance of seals. Overall, the assemblage taxonomically resembles that of the nearby, well-investigated site of Cerro Colorado.

Yu Liu, Qing-Hai Fan, Dong Ren

Chyzeriidae Womersley, 1954, is a family of trombidiform mites characterized by unique body structures and habits, though it has not been well studied. A new genus and species, Cretachyzeria macroseta gen. et sp. nov., in the subfamily Pteridopinae of Chyzeriidae, found in Cretaceous amber in Myanmar, provides the first formally described fossil species in this family. A phylogenetic study of Chyzeriidae based on postlarval morphology supported the morphological classification. The dorsal setae of Cretachyzeria macroseta gen. et sp. nov. are extremely long and dense, resembling the quills of a porcupine. This unusual morphological structure likely served specific biological functions. We hypothesize that these long setae functioned as a specialized defense, protecting the fragile abdomen and aiding in predator deterrence in its complex environment. Given the geological time frame of this fossil mite and the wide distribution of extant Chyzeriidae, we propose that the family existed prior to the breakup of Pangaea.

G. Kontakiotis, M. Shah, S. Ahmad et al.

Pietro Calzoni, LUCA GIUSBERTI, GIORGIO CARNEVALE

A Ypresian fish-bearing site was discovered in the late 1970s at Solteri (Trento, northern Italy), but its ichthyofauna, dominated by pelagic bony fishes, remained almost completely neglected for decades despite its potential interest. In fact, it represents the nearly coeval pelagic equivalent of the Lagerstätten of Bolca (Verona province, northeastern Italy), worldwide known for their extremely abundant and diversified, reef-associated fish fauna. The Solteri ichthyofauna, represented by almost 300 specimens, comprises what appears to be a mesopelagic assemblage including stomiiforms (Gonostomatidae and Phosichthyidae), myctophiforms (Myctophidae) and certain percomorphs (Gempylidae and Centrolophidae), most of them represented by new, so far undescribed taxa, of which the following are established herein: Ammutichthys loricatus n. gen. et sp., Eogorgon bizzarinii n. gen. et sp., Eomyctophum mainardii n. sp., Erebusia tenebrae n. gen. et sp. Krampusichthys tridentinus n. gen. et sp., Laurinichthys boschelei n. gen. et sp., Scopeloides bellator n. sp., Scopeloides violator n. sp., Solterichthys macrognathus n. gen. et sp., and Wudelenia diabolica n. gen. et sp. Solteri is of extreme relevance not only because it represents one of the most ancient Cenozoic deep-water Lagerstätten known, but it also allows us to define the structure of the western Tethyan pelagic fish communities during the demise of the Early Eocene Climatic Optimum (EECO), the interval of the Cenozoic with the warmest long-term global average temperature and highest CO2 levels (Filippi et al. 2024).

Miguel Ángel García-Villafuerte, Gerardo Carbot-Chanona

Syninclusions are palaeontological resources that provide palaeoautoecological evidence of fossil species and information on the biological interactions between different organisms that were part of a past ecosystem. Although palaeautoecological interactions in amber have been documented worldwide, interactions between predators and potential prey are rare. Here, we documented the first evidence in Miocene Chiapas amber of predator-predator-prey interaction involving two spider species and one insect: the araneophagous “pirate spider” Mimetus sp., the Theridiidae spider Thymoites carboti, and gall flies (Cecydomiidae). The interaction between Mimetus sp. and T. carboti is documented as a possible case of araneophagy or opportunism. Also, the first evidence of a web built by some members of the Thymoites genus is presented. The taphonomic analysis of the amber piece indicated that they were all captured at the same time under the same resin flow.

Serjoscha W. Evers, Kimberley E. J. Chapelle, Walter G. Joyce

Abstract Trionychid (softshell) turtles have a peculiar bauplan, which includes shell reductions and cranial elongation. Despite a rich fossil record dating back to the Early Cretaceous, the evolutionary origin of the trionychid bauplan is poorly understood, as even old fossils show great anatomical similarities to extant species. Documenting structural detail of fossil trionychids may help resolve the evolutionary history of the group. Here, we study the cranial and mandibular anatomy of Plastomenus thomasii using µCT scanning. Plastomenus thomasii belongs to the Plastomenidae, a long-lived (Santonian–Eocene) clade with uncertain affinities among trionychid subclades. The skulls of known plastomenids are characterized by unusual features otherwise not known among trionychids, such as extremely elongated, spatulate mandibular symphyses. We use anatomical observations for updated phylogenetic analyses using both parsimony and Bayesian methods. There is strong support across methods for stem-cyclanorbine affinities for plastomenids. The inclusion of stratigraphic data in our Bayesian analysis indicates that a range of Cretaceous Asian fossils including Perochelys lamadongensis may be stem-trionychids, suggesting that many features of trionychid anatomy evolved prior to the appearance of the crown group. Divergence time estimates from Bayesian tip-dating for the origin of crown Trionychia (134.0 Ma) and Pan-Trionychidae (123.8 Ma) constrain the evolutionary time span during which the trionychid bauplan has evolved to a range of < 11 million years. Bayesian rate estimation implies high morphological rates during early softshell turtle evolution. If correct, plastomenids partially fill the stratigraphic gap which results from shallow divergence times of crown cyclanorbines during the late Eocene.

Andros Daniel Cruz Salmeron, Hideko Takayanagi, Shigeyuki Wakaki et al.

Abstract We investigated the water-mass structure on the Okinawa Trough and Pacific sides of the southern Ryukyu Island Arc (Yonaguni, Iriomote, and Ishigaki subareas) using the Nd isotope composition (143Nd/144Nd ratios; expressed as εNd values) of benthic foraminiferal tests in surface sediments, which reflect bottom-water composition, along with hydrogen and oxygen isotope compositions (δD and δ18O values, respectively) and physical properties (temperature and salinity) of seawater. The Okinawa Trough side has lower εNd values than the Pacific side due to continental/island material inputs characterized by relatively low εNd values. Moreover, within the Okinawa Trough, other processes control the Nd behavior of seawater and primarily affect the Yonaguni and Iriomote subareas, as follows. (1) Surface and subsurface waters are influenced by Taiwanese river discharge combined with temporospatial variations in oceanographic conditions including Kuroshio Current meandering. (2) Intermediate water is characterized by low εNd values (down to − 8.2), possibly attributable to sediment plumes and turbiditic fluxes. (3) The εNd values of bottom water indicate upwelling and vertical mixing, with composition therefore being similar to those of intermediate water. The εNd profiles are better defined on the Pacific side. High εNd values occur in surface and subsurface (< 300 m depth, potential density < 25.0 kg m−3) waters, and low values (down to − 7.0) occur in subsurface–core-intermediate water (400–600 m depth, 26–27 kg m−3). εNd values increase slightly to − 4.0 below 750 m depth and remain constant down to about 2000 m depth, below which deep water shows a slight decrease in εNd values. Intermediate and bottom/deep waters are distinguished from upper layers by their lower δD and δ18O values.

Boyang Sun, Yan Liu, Shanqin Chen et al.

Abstract Here, we report well–preserved skulls and postcranial specimens of genus Hippotherium from the Linxia Basin, Gansu, China. Based on morphological comparison, the species of Hippotherium in China, Hippotherium weihoense and Hippotherium chiai, should be ascribed to the same species, H. weihoense. We also reviewe other Old World hipparion species in the very early Late Miocene and figure out two evolutionary routes: the Hippotherium and Cormohipparion lineages. Analysis of locomotive ability indicates that H. weihoense likely lived in an open habitat, whereas other species of Hippotherium likely lived in closed habitats. This result shows a palaeoecological pattern in the early Late Miocene in Eurasia influenced by a series of geological events as aridification of mid–latitude Asia progressed, whereas Europe and North Africa remained relatively humid. As the genus originated from East Asia, hipparion horses divided rapidly into different groups with differing functional morphology to occupy diverse niches.

Stephen Kershaw, Consuelo Sendino

Abstract Stromatoporoid sponges were very abundant during the middle Palaeozoic Era and are thought to disappear at the end of the Devonian Period in the Hangenberg Crisis. However, there are records of organisms with stromatoporoid-type structure in Carboniferous strata, the subject of this study. The Viséan fossil Labechia carbonaria Smith 1932 has been discussed previously in literature and its affinity has not been confirmed. In this study, the type material of L. carbonaria collected from the middle part of the Frizington Limestone Formation (previously called Seventh Limestone), Holkerian Substage, stored in the Natural History Museum (London, UK) and British Geological Survey (Keyworth, UK) was re-examined. The Holkerian Substage, in which L. carbonaria was found, lies between ca 335–339 Ma, and the Frizington Limestone Formation ranges from topmost Arundian to upper Holkerian, so middle Frizington Limestone Formation is likely approximately 337 Ma. L. carbonaria comprises thick long pillars connected by thin curved cyst plates consistent with the structure of the stromatoporoid genus Labechia. However, a common opinion is that L. carbonaria fossils may be mistaken for fragments of rugose corals, but there are problems with assigning it to the Rugosa. In vertical section (VS) L. carbonaria could be mistaken for a transverse section (TS) of a Carboniferous rugose coral. However, in TS L. carbonaria shows the rounded cross sections of stromatoporoid pillars. If it was a coral, septal sheets of the VS of a coral should be seen. For a rugose affinity to still apply, a coral structure would have to be composed of free trabeculae, but these are not known after the middle of the Devonian Period; there are no corals of Early Carboniferous age with the structure of L. carbonaria. Another interpretation, that L. carbonaria is a chaetetid, is discounted because it lacks calicles and is very different in structure from chaetetids. We conclude that L. carbonaria is a stromatoporoid. Because the beginning of the Carboniferous Period was ca 359 Ma, stromatoporoids thus occur approximately 22 million years after their purported disappearance at the end-Devonian Hangenberg Crisis. L. carbonaria, together with other rare occurrences in Carboniferous strata of stromatoporoid-form sponges Newellia mira (Newell) in USA, and uncertain taxa Komia Korde and Palaeoaplysina Krottow that have been attributed to stromatoporoids by some authors, supports some published views that end-Devonian stromatoporoid extinction may not have been as final as is traditionally interpreted. Thus Mesozoic stromatoporoids may represent resurgence of sponge lineages that survived the late Palaeozoic, perhaps in uncalcified form. Palaeogeographically, during the Early Carboniferous, the UK was positioned in low latitudes and in a central location of global distribution of reefal buildups during the late Palaeozoic continental assembly towards Pangaea. Thus it is curious that L. carbonaria is found in only one place; future search may determine its true palaeographic distribution, with potential reconsideration of the extinction of stromatoporoids at the end of the Devonian Period.

Comisión Organizadora de las XXXII JAPV / VII JTPV

Alison M Murray

n/a

Santanu Banerjee, Udita Bansal, Anup Vilas Thorat

This study presents a review on palaeogeographic implications and temporal variations of glaucony covering both modern and ancient records. Phanerozoic glaucony preferably forms in a shelf depositional setting. Deep marine conditions and low seawater temperature discourage formation of glaucony. Around 75% of glaucony is recorded from the Cretaceous to the Holocene sediments, which are related to the abundance of the most common substrates, faecal pellets and bioclasts. TFe2O3 (total), Al2O3, K2O and MgO contents of glaucony vary appreciably through geological time. While TFe2O3 content of most Mesozoic and Cenozoic glaucony exceeds 20%, it is always less than 20% in Precambrian varieties. High K2O, Al2O3, MgO and low TFe2O3 distinguish the Precambrian glaucony from its Phanerozoic counterpart. Precambrian glaucony, preferably formed within a K-feldspar substrate, is always rich in potassium irrespective of its degree of evolution, while high K-content in Phanerozoic evolved glaucony indicates significant stratigraphic condensation. K2O vs. TFe2O3 relationship of glaucony exhibits three different evolutionary trends corresponding to three common modes of origin. Depositional conditions may influence the composition of glaucony as slightly reducing conditions favour Fe enrichment, whereas oxidising conditions cause Fe depletion in glaucony.

TEA KOLAR-JURKOVSEK, BOGDAN JURKOVSEK, DUNJA ALJINOVIC

Detailed conodont biostratigraphy and lithostratigraphy of the Late Permian and Early Triassic beds were studied at the LukaC section in western Slovenia. The analyzed section is composed of the Bellerophon Formation ("evaporite-dolomite member") and the newly introduced Lukaè Formation ("transitional beds", "streaky limestone member" and "carbonate-clastic beds member"). The Permian-Triassic boundary interval is represented by "transitional beds" of carbonate facies deposited in shallow restricted marine conditions. The presence of H. parvus in sample L1 in the "transitional beds" marks the systemic boundary between Permian and Triassic. The studied interval is characterized by a diverse microfauna that contain conodonts, foraminifers, ostracods and gastropods. Six conodont zones have been recognized, in ascending order, the latest Changhsingian (uppermost Permian) praeparvus Zone, and the Griesbachian (lowermost Triassic) parvus, lobata, staeschei-isarcica, postparvus and anceps zones. This faunal succession represents the first known and the most complete conodont biozonation across the Permian-Triassic interval from the entire Dinaric region. The recognized conodont biozones can be correlated with the biozonation of the Southern Alps and of the GSSP Meishan D section.

F. Witzmann, J. Müller

No abstract is available for this article.doi:10.1002/mmng.200800005

Magda da Silva Reis, Antonio Rodrigues Fernandes, Catherine Grimaldi et al.

The transformations in the Amazonian ecosystems, that occur from colonization process, it have been enough studied, however little have been considering the variations of the characteristics of the soil in the landscape. With the objective of evaluating the variation of the soil of a landscape of the Marabá (PA) region, a study was carried through involving the granulometric and organic composition of the soil. It tries to explain the variation of those characteristics in relationship the pedogenetics processes. The samples were removed of vertical profiles, in the top (Latosols), hillside (Cambisols) and low slope (Gleysols), in a topossequence with 300 m of extension, cultivated with Brachiaria brizantha. The analyses demonstrated the clay prevalence in Latosols and in Cambisols, and of sand in Gleysols, besides an accumulation of organic matter in surface. The increase in the silte values in depth is current of the presence of the alterites, that appears in variable depth according to the soil class. Differentiat pedogenetic intensity in function of the declivity and the form of the source, provoked variations the granulometric and organic constitution of the soil, throughout the profiles the topossequence, that contributed for characterization of a pedologic, composed system of Latosols, Cambisos and Gleysols, of high the low one source, respectively.

DARIO VARRONE, DANIELLE DECROUEZ

The Trucco Formation and the Nummulitic Limestone (Dauphinois Domain, Maritime Alps) are characterized by abundant larger foraminifera, specifically nummulitids, orthophragminids and encrusting foraminifera. In the Maritime Alps, previous studies suggest a late Lutetian age for the Trucco Formation and a late Lutetian-Priabonian age for the Nummulitic Limestone. Biostratigraphic analysis of the nummulitids, in 11 stratigraphic sections, allowed us to distinguish 3 biozones: MALF1 Zone: defined by the presence of Nummulites brongniarti d’Archiac & Haime, N. puschi d’Archiac, N. perforatus de Montfort, N. striatus (Bruguière), N. cf. dufrenoyi d’Archiac & Haime, N. variolarius/incrassatus and Operculina schwageri Silvestri. MALF2 Zone: defined by the presence of Nummulites perforatus de Montfort, N. striatus (Bruguière), N. cf. dufrenoyi d’Archiac & Haime, N. variolarius/incrassatus and Operculina schwageri Silvestri. MALF 3 Zone: defined by the presence of gr. Nummulites variolarius/incrassatus, N. striatus (Bruguière) and Operculina schwageri Silvestri. According to current larger foraminiferal biozonal schemes, the age of these local biozones corresponds to the Bartonian p.p. Moreover, the comparison with biostratigraphic schemes established for the Dauphinois Domain and for the Tethyan area evidences that several typical nummulitid species of the late Bartonian are lacking in the southern Dauphinois Domain, probably due to a paleogeographic control.

Hélida Bruno Nogueira Borges

A ecologia da polinização e o sistema reprodutivo de Centrosema pubescens Benth., uma espécie arbustiva, foram estudados numa floresta tropical do Acre. A antese é diurna e as flores são visitadas, basicamente, por abelhas (9 spp.) e vespas (5 spp.). A guilda de polinização é composta por abelhas dos gêneros Xylocopa, Bombus, Euglossa, Exarete, Mesoplia, Megachile e Trigona e por vespas das famílias Polybinae e Scoliidae. Uma espécie de abelha e uma de mariposa apresentam comportamento de pilhadores de néctar. A espécie é autocompatível, mas produz frutos através de autofecundação e fecundação cruzada. Agentes polinizadores não são exigidos para a produção de frutos, uma vez que as flores têm apresentação secundária dos grãos de pólen.

H.-P. Schultze

No abstract is available for this article.doi:10.1002/mmng.20040070102

D. Weyer, R. Feist, C. Girard

New recoveries of Trilobita, Anthozoa and Conodonta from the linguiformis Zone close to the Frasnian/Famennian boundary and Immediately preceding the Upper Kellwasser Event level at Schleiz (Thuringia) are investigated. The trilobites species are Harpes neogracilis Richter &amp; Richter, 1924, Palpebralia cf. brecciae (Richter, 1913) and Acuticryphops acuticeps (Kayser, 1889), the latter is represented by several morphs with different numbers of eye-lenses; the trend to eye-reduction is discussed. The Rugosa fauna that was nearly unknown from the psychrospheric facies worldwide, comprise six taxa of the Cyathaxoniina. The rich conodont faunas permit tracing the exact boundary between the top of the Late Palmatolepis rhenana Zone and the Palmatolepis linguiformis Zone.Im Niveau der Frasnium/Famennium-Grenze werden neue Fossilfunde der letzten Trilobita, Anthozoa und Conodonta aus der linguiformis-Zone (vor dem Oberen Kellwasser-Event) mitgeteilt. Harpes neogracilis Richter &amp; Richter, 1924, Palpebralia cf. brecciae (Richter, 1913) und Acuticryphops acuticeps (Kayser, 1889) wurden beobachtet; bei letzterem wird an Hand verschiedener Morphen mit unterschiedlicher Linsenzahl der Trend zur Augenreduktion diskutiert. Von der Rugosa-Fauna, die weltweit aus solcher psychrosphaerischer Fazies fast unbekannt blieb, sind sechs Taxa der Cyathaxoniina skizziert. Die reichen Condonta-Faunen erlauben eine präzise Grenzziehung zwischen dem Top der Late Palmatolepis rhenana-Zone und der Palmatolepis linguiformis-Zone.doi:10.1002/mmng.20030060104