Coralline red algal assemblage from the Middle Pliocene shallow-water temperate carbonates of the Monte Cetona (Northern Apennines,Italy)

During the Pliocene and Pleistocene, the Monte Cetona (Northern Apennines, central Italy) was part of an elongated island. The Middle Pliocene deposits around the Monte Cetona are represented by shallow-water marine carbonates rich in coralline red algae and bryozoans. These skeletal carbonates, characterising a coralline algal-dominated factory, were analysed in terms of microfacies, taxonomy, and growth-forms of coralline red algal assemblage. Three microfacies were distinguished on the basis of component distribution and fabric analysis: coralline algal rudstones, coralline algal floatstones, and bioclastic packstones. Skeletal components are commonly abraded, bioeroded, and encrusted. The shallow-water skeletal carbonates are strongly bioturbated and any primary sedimentary structure is obliterated. The distribution of the coralline growth-forms suggests a decreasing hydrodynamic gradient from the coralline algal rudstone, through the coralline algal floatstone to the bioclastic packstone microfacies. The coralline algal flora consists of eight species representing the subfamilies Lithophylloideae, Mastophoroideae and Melobesioideae. The assemblage is dominated by lithophylloids. Other biogenic components are bryozoans, barnacles, echinoderms, and benthic foraminifera. These coralline algal assemblages were deposited just above the fair-weather wave base and indicate a shallow-marine temperate water setting for the eastern Tyrrhenian Sea during the Mid Pliocene.     

Environmental change, bog history and human impact around 2900 b.c. in NW Germany–preliminary results from a dendroecological study of a sub-fossil pine woodland at Campemoor, Dümmer Basin

This paper presents a detailed dendroecological analysis of remains from a sub-fossil pine forest at the Campemoor in the Dümmer basin, NW Germany and of pine timbers from a contemporaneous Neolithic trackway Pr 32 through the Campemoor. Changes in growth pattern and population dynamics of the pines are discussed in context with the time of construction of the trackway. The findings date to the period around 3000 b.c. Together with palaeobotanical investigations (pollen and macro remains) and the archaeological results (trackway) the dendroecological analysis mirrors environmental changes and the response of people to these changes. In order to test this local development for a possible climate background, ring-width variability and population dynamics of the Campemoor pines and of the overall data set of Lower Saxonian sub-fossil oaks from bogs have been compared. The results of these investigations clearly indicate a common widespread turn from drier to more humid climate conditions as trigger for the transition period, initiating the raised bog growth. It happened in two phases at the beginning of the 3rd millennium, interrupted by a drier period between 2825 and 2770 b.c. Afterwards large areas of former settlement sites within today's Campemoor became inaccessible and were covered by raised bog.     

The Late Pleistocene faunal assemblage from Cava Muracci (Latium,Italy): Palaeoenvironmental implications for coastal central Italy during MIS 3

Palaeoenvironmental information on Marine Isotope Stage 3 (MIS 3) coastal Latium is sparse, mainly based on studies of isolated faunal assemblages or long pollen records from lake sediments, often of insufficient resolution to aid in palaeoenvironmental reconstruction. This study describes in detail the Late Pleistocene faunal assemblage from layers SU11 and SU12 of Cava Muracci (Cisterna di Latina, central Italy), the first of which is a partially-preserved hyena den. The first multi-disciplinary palaeoenvironmental reconstruction of coastal Latium between 34–44 ka BP, a critical time span for the presence of the latest Neanderthals and the arrival of Anatomically Modern Humans (AMH), is provided combining palaeoecological inferences from a previous pollen study of hyena coprolites with the palaeontological study described here. The results indicate a temperate climate and a landscape characterised by the coexistence of at least three habitats within a short distance between the coastline and the inland mountains, suitable for a wide variety of species.     

Alveolina-dominated assemblages in the early Eocene carbonates of Jaintia Hills,NE India: Biostratigraphic and palaeoenvironmental implications

Larger benthic foraminifera (LBF) are significant proxies in biostratigraphy and also act as excellent indicators of shallow-marine carbonate environments in fossil series. The Palaeogene LBF recorded from Meghalaya, NE India (eastern part of the relic eastern Tethys/Neo-Tethys) have high potential for dating shallow-marine sediments and documenting the multiple episodes of carbonate sedimentation that have contributed to the development of the Sylhet Limestone Group. Early Eocene witnessed the proliferation of LBF species worldwide, the phenomenon better known as the Larger Foraminiferal Turnover (LFT). Genera like Alveolina, Nummulites and Orbitolites with broad species complexes thrived as the dominant LBF amidst numerous other taxa on the verge of extinction or only surviving as stable forms. The current study emphasizes on the biostratigraphic and palaeoenvironmental account of the early Eocene Umlatdoh Limestone successions outcropping in the Jaintia Hills of Meghalaya, primarily based on the recorded species of Alveolina and other larger benthic foraminifera. Five species of Alveolina — A. oblonga, A. schwageri, A. cf. ruetimeyeri, A. aff. haymanensis and A. aff. varians are recorded in the evaluated sections that indicate an early Eocene age corresponding to the Shallow Benthic Zone 10. Major carbonate facies types in the present assessment include oolitic-smaller benthic foraminiferal -green algal grainstone–packstone, smaller miliolid-Alveolina grainstone, green algal-benthic foraminiferal grainstone, larger porcellaneous (Alveolina) grainstone-packstone, Alveolina-nummulitid grainstone-rudstone, and nummulitid grainstone-rudstone, which indicate a shallow marine, high-energy depositional environment ranging from shoal-sandy bars to a distal inner ramp setting.     

Tomographic reconstructions of crab burrows from deltaic tidal flat: Contribution to palaeoecology of decapod trace fossils in coastal settings

Trace fossils play an important role in reconstructing palaeoecology and depositional environment. Their palaeoecological implications can be better understood when the trace makers are correctly identified. Neoichnology studies the burrow morphologies, behavioral ecology of modern organisms and their interaction with the environment. Neoichnology is of great significance in linking burrowing behaviors of extant organisms with interpretation of trace fossil palaeoecology. This paper reports a study on burrows produced by the ocypodid crab (Macrophthalmus japonicus De Haan) in the tidal region of the Yellow River Delta using CT scanning techniques. Our results show that M. japonicus produces abundant I-, U-, and Y-shaped burrows in a mudflat of the delta. These domicile structures are similar in morphological characteristics to the trace fossil Psilonichnus, suggesting M. japonicus as its possible additional trace maker. Our study supports the usage of Psilonichnus as a significant palaeoenvironmental indicator for coastal and shelf environments. Furthermore, this study highlights the great potential of applying CT techniques in future ichnological-related studies.     

Occurrence of Phoma Sacc. in the phyllosphere of Neogene Siwalik forest of Arunachal sub-Himalaya and its palaeoecological implications

The present study reports in situ occurrence of two new epiphyllous fungal species of Phomites (comparable to modern genus Phoma Sacc.) on angiospermic leaf remains recovered from the Siwalik sediments (middle Miocene to early Pleistocene) of Arunachal Pradesh, eastern Himalaya. We describe two new species i.e. Phomites siwalicus Vishnu, Khan et Bera S, sp. nov. and Phomites neogenicus Vishnu, Khan et Bera S, sp. nov. on the basis of structural details of pycnidia. The pycnidium is a globose or slightly lens-shaped, ostiolate with a collar layer consisting of thick walled cells, sunken in leaf cuticle, with one-celled conidiospores and short-ampulliform conidiogenous cells. Host leaves resemble to those of extant Dipterocarpus C. F. Gaertn., Shorea Roxb. ex C. F. Gaertn. (Dipterocarpaceae), Dysoxylum Blume (Meliaceae), and Poaceae Barnhart. In situ occurrence of two Phomites morphotypes on the said leaf remains suggests a possible host–parasite interaction in the moist evergreen forest of Arunachal sub-Himalaya during Mio-Pleistocene period. The occurrence of Phomites in appreciable numbers indicates a humid climate favored by high rate of precipitation during Siwalik sedimentation, which is also consistent with our previously published climatic data obtained from the study of the macroscopic plant remains.     

广西南丹拉要泥盆纪礁组合剖面的古生态特征

广西南丹拉要泥盆纪生物礁发育在台地的边缘,是一个礁、滩、开阔台地沉积互相交替的叠置礁。礁组合中出现5个主要的生物群落。其中以层孔虫、床板珊瑚为主的 Stromatopora-Alveolites群落是最重要的造礁群落。这些群落有规律地分布在礁组合的不同部位。它们在剖面上的垂直分布显示礁组合的发育过程分成3个大的旋回,其中包括9个次一级的成礁旋回。旋回反映了海水深浅的变化。     

贵州独山中泥盆世动藻迹生态习性探讨

贵州独山中泥盆统产有丰富的遗迹化石Zoopkycos,现从其产出的特征和古生态等方面对其生活习性进行探讨。认为分布于静水、贫氧、有机质丰富环境的Zoopkycos为螺旋向上的内生觅食构造;边缘管一端通过中央通道与海水相通,呈“J”形;蹼状构造系造迹生物觅食区域的扩大、边缘管增大而形成;同一个体的Zoopkycos可以分出许多的与蹼状构造变化规律相近的、具同一边缘管的觅食序列(food-system),每一觅食序列的边缘管具有一端向上与中央通道相通,另一端向下与相邻觅食序列的边缘管相联;螺旋的疏密、大小与相对沉积速度有关。产于独山地区中泥盆统的Zoopkycos的造迹生物可能是星虫类(sipunculids)。     

Palaeoecological significance of calcimicrobial communities during ramp evolution: An example from the Lower Cambrian of Germany

Summary The palaeoecology of calcimicrobial communities from the only Gondwana-related Lower Cambrian in Central Europe (eastern Germany, carbonates and siliciclastics) has been studied. Six morphological groups of calcimicrobes are described. Some of them show a significant ability for sediment stabilization and construction of biohermal reef mounds. Other types of calcimicrobes were more common in biostromal thickets. Some of them were capable of populating different environments, growing in different modes and on different substrates. AnEpiphyton-archaeocyathan reef mound is described, illustrating the importance of calcimicrobes for mound formation. The fossil communities together with a complex of sedimentary features allow a reconstruction of the depositional history of the environment. Based on comparison with similar Gondwanan Lower Cambrian successions (Sardinia/Italy, Spain) and facies development a model is proposed describing the sedimentary history. Three depositional stages are distinguished: (1) deep subtidal ramp, (2) shallow subtidal ramp, (3) shallow subtidal to intertidal mixed siliciclastic-carbonate ramp with migrating oolitic shoals. In spite of similarities with the deposits in southern Europe, some distinct differences exist with respect to the succession of facies, the completeness of the sections, the fossil spectrum, and the nature of the siliciclastic sediments. For the German Lower Cambrian, a facies development from a low energy deep environment to a high energy shallow environment (partly restricted and with some evaporites) can be reconstructed. As compared with Sardinia and Spain, the depositional environment of the eastern German Lower Cambrian successions was predominantly characterized by low-energy conditions.