Palaeobiodiversity and Palaeoenvironments最新文献

Marly nummulite limestones of the Tabas Block of central Iran (Jiroft area) contain armoured burrows of the problematic ichnofossil Nummipera eocenica. These burrows are covered with tests of Nummulites cf. praelyelli and Nummulites deshayesi. The studied traces most closely resemble morphotype C of N. eocenica from the Eocene of the Tatra Mountains. The Iranian specimens occur in marly limestone that was deposited in a moderate to low energy environment on the shallow part of a ramp, although occasionally sediments indicate wave action and storm influence in high-energy conditions. The trace maker may have selectively used microspheric forms or B-forms of Nummulites by means of its appendages. Moreover, A-forms are dominant in accumulations of foraminifera in the studied section, but the trace maker obviously preferred the thinner test B-forms that are mainly saddle and flat shaped forms (Nummulites cf. praelyelli) over the lenticular and thick test forms (e.g. N. deshayesi). In addition to the protection against the episodic hydrodynamic activity, it is possible that one of the main reasons behind the reinforcement of burrow walls may have been the need for protection against predators. The trace makers were likely crustaceans or alternatively onuphid polychaetes.

Microbial communities are important components controlling the fidelity of fossil fish preservation. The Eocene Green River Formation lagerstätten, exceptionally preserved fossil deposits, provides an opportunity to examine the role of microbial communities and their metabolic byproducts, such as chemical precipitated in this spectacularly preserved fish deposit, famous throughout the world. Field emission scanning electron microscope (FESEM) and energy dispersive spectroscopy system (EDS) examination of a well-preserved Knightia eocaena from the Eocene Green River Formation documents the presence of bacteriomorphs. Bacteriomorphs in a sample from the Fossil Butte Member of the Green River Formation consists of spherical structures, coccoid-type bacteria, fibres from two-sized populations of filamentous bacteria, probable filamentous cyanobacteria, capsule-shaped, and bacilliform bacteria, all associated with framboidal iron hydroxide.

Bacteriomorphs consist of external molds composed of nanometer-scale calcium carbonate spheres. Fe-oxide framboids have an amorphous exterior and a sieve-like internal structure. The sieve-like structure consists of nanometer-scale pores, probable sites of bacterial cells with walls composed of 100-nanometer-scale spheres. Fe-oxides are consistent with bacterially mediated precipitation of pyrite followed by an oxidation event. Preserved bacteriomorphs are consistent with degradation of soft tissue, limiting the preservation of soft tissue and leaving bone and scales with no appreciable soft tissue. The microfossils are restricted to the skeleton and are not found in the surrounding rock matrix, suggesting larger microbial mats may not have been present and possibly did not have a significant impact on the preservation of this specimen.

I here describe lacertids from the classic Węże I locality in southern Poland (?Pliocene deposits) based on six previously undescribed jaws: an incomplete left maxilla, two dentaries and three mandibles. These jaws collectively provide considerable data on the morphology of the maxilla, dentary, teeth, coronoid, splenial, angular, surangular and prearticular. All six jaws can be unequivocally allocated to Lacertidae and five of those are allocated to European green lizards of the Lacerta viridis group. Currently, La. viridis has regionally extinct or probably extinct status in Poland. The material from Węże I provides evidence that European green lizards had a large geographic distribution in Europe, including Poland during the ?Pliocene. One mandible fragment appears to be slightly different and is allocated to Lacertidae indet. That mandible might point to a higher taxonomic diversity of lacertids in this locality. However, that interpretation needs to be viewed with caution, because based on such limited material, individual and/or ontogenetic variation cannot be ruled out. To reveal the real taxonomic palaeodiversity of lacertids in Węże I, new and more complete cranial material is needed. In addition, this article provides insights into the comparative osteology of skulls and selected cranial elements in lacertids.

This paper provides an upgrade of Hystrix parvae, which so far is the smallest and oldest extinct species of Hystrix s. str. The new data derive from the exceptionally rich new fossil collection of the locality Kohfidisch in Austria, that comprises more than 100 fossils. The detailed descriptions are supported by enamel microstructure analysis of incisors, and x-ray microcomputed images (microCT) of the partial skull, upper and lower jaws and teeth. The tooth pattern and sizes show wide ranges, depending on the ontogenetic stage, tooth position and stage of wear. The deciduous D4/d4 and the permanent lower p4-m3 are identified as low crowned or brachydont. The mean hypsodonty index of m1/2 is 69%. The permanent upper P4-M3 are brachydont to mesodont. The mean hypsodonty index of M1/2 is 114%. The karstic cave and fissure system of Kohfidisch provided an ideal nursery environment as evidenced by numerous deciduous teeth in different ontogenetic stages. The age of the fauna is Late Miocene (lower Turolian, MN11), around 8.6 million years.

Despite the presumably lower diversity of Palaeozoic echinoids compared to their post-Palaeozoic relatives, a radiation during the Mississippian marked a first brief "golden age" of sea urchins. Carboniferous echinoid faunas feature distinct and specialised groups compared to those of the Devonian, suggesting important evolutionary changes during the Late Devonian, although the role of biotic crises like the Kellwasser and Hangenberg Events in these changes remains poorly known. This study describes an exceptionally well-preserved echinoid fauna from the middle to upper Famennian of Velbert near Düsseldorf, Germany. Description of six new species belonging to the lepidocentrid, hyattechinid, proterocidarid and archaeocidarid lineages along with a seventh species based on isolated remains greatly add to the knowledge of Late Devonian echinoids. The newly described genera Thielechinus gen. nov. and Velbertechinus gen. nov. represent the most derived proterocidarids and archaeocidarids known from the pre-Carboniferous. Moreover, the fossils offer new insights into phylogeny, ontogeny, and palaeobiology of several stem-group echinoid lineages. The fauna resembles Carboniferous echinoid faunas much more than earlier Devonian faunas, thus providing evidence that crucial developments had occurred from the Frasnian to the Famennian, possibly linked to global changes associated with the catastrophic Kellwasser Event. These developments include the appearance of several specialised lineages that would become important in the Late Palaeozoic as well as evolutionary innovations leading up to the establishment of the crown-group echinoid body plan.

Bryozoan material from the Ferques Formation (Upper Devonian, Frasnian), Boulonnais, France contains two cystoporates Cystiramus cf. kondomensis Morozova, 1959 and Canutrypa francqana Bassler, 1952, a new trepostome species Dyoidophragma bigeyae n. sp., as well as two fenestrates Hemitrypa sp. and Anastomopora inflata (Bigey, 1988b). The diagnosis of the genus Dyoidophragma Duncan, 1939 is revised. The species composition reveals palaeobiogeographic relations to the Middle and Upper Devonian of Belgium, Germany and Poland, as well as possible relation to the Upper Devonian of Kuznetsk Basin in Russia.

A total of 228 well-preserved fossil leaves have been discovered from the Middle Jurassic Haifanggou Formation in Baimashi Village, Lianshan District, Huludao, Liaoning. To gain insights into the plant-insect interaction during the Middle Jurassic in western Liaoning, this paper aims to identify and quantitatively analyse evidence of insect damages on fossil leaves from the Haifanggou Formation based on previous taxonomic research. Seven insect damage types (DTs) assigned to three functional feeding groups (FFGs) are identified. Margin feeding is the most prevalent FFG, followed by hole feeding and surface feeding, suggesting that Orthoptera and Hymenoptera with chewing mouthparts were dominant during the Middle Jurassic in this area, with Hemiptera and Coleoptera also playing a significant role. The primary plant groups targeted by insects are Ginkgophytes, followed by Pteridophytes, Cycadophytes and Czekanowskiales, with Cycadophytes exhibiting the highest average percentage of damaged leaf perimeter and area. This could be attributed to the physical insect resistance mechanism of conifers, as well as the chemical defense capabilities of Pteridophytes and Ginkgophytes during the Middle Jurassic. Plants and insects from the Haifanggou Formation are highly diverse, and approximately 17.54% of the observed fossil leaves show traces of insect damage, probably indicating the presence of active insects in the area and a close relationship between plants and insects during the Middle Jurassic. Considering the floristic composition and the climate-indicative plant groups, it can be inferred that the climate in the study area during the Middle Jurassic was warm and humid, potentially accompanied by intermittent droughts.

Paleomydas menatensis gen. et sp. nov., the third known fossil mydid fly, is described from the Paleocene of Menat (France). The fossil fly is remarkable in its very broad hind femur, a rather infrequent character in this family, which is mainly present in the Neotropical genera Mapinguari and Ceriomydas, and to a less pronounced degree, in the Nearctic genus Phyllomydas. But the lack of information on the antenna and genitalia structures forbids us to specify its relationships within the Mydidae more precisely. Thus we propose to attribute it to a new genus. The systematic affiliation of the late Eocene Mydas miocenicus from Florissant is discussed. Because of the rarity of Diptera in the insect assemblage of the Menat outcrop, the present discovery could suggest that this nowadays rather rare family was more frequent during the Paleocene than today.

We examined the gut contents of a fossil giant pelobatid tadpole from the late Oligocene of Enspel, Germany, and discovered that it contains mainly pollen from spruce (Picea) but also pollen from pine (Pinus), beech (Fagus), and elm (Ulmus). Pollen in the gut of the fossil tadpole and other plant fossil records from this locality suggest that the regional vegetation around Enspel was characterised by mixed conifer and broadleaved forests with a prominent deciduous angiosperm component. Palaeoclimatic estimations indicate that the area endured a fully humid warm temperate climate with a hot to warm summer and a distinct temperature difference between seasons. The pollination period of potential modern analogues of the plant taxa discovered in the gut of the fossil tadpole hints that it was feeding on pollen floating on the water surface of the ancient Enspel Lake during late spring or earliest summer. Comparable analyses from the guts of extant pelobatid tadpoles have shown a broad spectrum of food remains, including whole/or parts of algae, protists, protozoans, macrophytes, rotifers, crustaceans, and pollen. It seems that living pelobatid tadpoles are indiscriminate and opportunistic feeders able to adapt and change their feeding behaviour according to the available food source. The time of origin and evolution of pollen feeding in tadpoles is obscure. Our discovery indicates that pelobatid tadpoles were already feeding on pollen in the late Oligocene, and the amount and purity of pollen filling the gut suggests intentional surface feeding.