陕西宁强埃迪卡拉纪晚期高家山生物群中黄铁矿化化石的成岩及风化过程

陕南埃迪卡拉纪晚期的高家山生物群中部分化石以黄铁矿化三维立体保存软躯体管状化石为主要特征。对野外识别出的具有不同风化程度的3类粉砂岩进行了详细的手标本特征对比和扫描电子显微镜测试对比研究。锥管虫（Conotubus）的化石成岩学特征表明黄铁矿最先沉淀,随后方解石充填于黄铁矿留下的空隙或空腔中。这些化石所经历的第一期风化作用相对较弱,保留了大量的原始化石成岩学信息;第二期风化作用则可能形成于一个氧化条件较强的环境中。     

Internal supporting structures of some Late Ordovician graptolites from South China revealed by micro-CT

Three-dimensionally preserved pyritic internal moulds of the Late Ordovician graptolites Appendispinograptus leptothecalis and Styracograptus chiai from the Upper Ordovician Wufeng Formation of the Daheba section, Hunan Province, South China, were imaged by micro-CT. The distinctive pea-shaped pits/dimples aligned in a zigzag line arising from the second/third thecal pair on the tubarium in these species are interpreted as the surface expression of the junction between the lateral thecal walls and the thickened internal cross-bars that support the nema. The relations between different internal structures such as the nema, median septum, aboral lists, interthecal septa and cross-bars are summarized, and examples of these supporting systems in different taxa are illustrated. The presence of isolated cross-bars in different diplograptid tubarium may suggest that they have evolved as a result of constructional restrictions.     

陕南晚震旦世Gaojiashania的保存特征及形态解释

陕西宁强地区灯影组高家山段地层中特异原地埋藏的管状化石Gaojiashania Yang et al.,1986为体似蚕状或带状,直或微弯,由密集圆环（或皱脊）彼此连接在一起形成的管状化石,对化石的埋藏及保存特征的研究表明,不同的矿化阶段形成不同的保存特征,早期黄铁矿化对化石保存起着重要作用。Gaojiashania以其特殊的圆环叠置的保存方式,与软躯体蠕形动物化石以及遗迹化石的保存迥然不同,推测Gaojiashania生物体已具有分节现象,在成分上也有差别,圆环部分可能具有一定的矿化,属于较为高等的生物门类。     

A pyritized lepidocoleid machaeridian (Annelida) from the Lower Devonian Hunsrück Slate,Germany

A machaeridian, Lepidocoleus hohensteini sp. nov., is described from the Hunsrück Slate (Lower Emsian) of Germany. The available material includes a unique example preserving evidence of the soft tissues, only the second machaeridian specimen to do so and the first lepidocoleid. This specimen shows that the plates are attached to alternate segments in the trunk. The morphology is consistent with an annelid affinity of the Lepidocoleidae and confirms the unity of the Machaeridia. This discovery adds an important group to the known diversity of this famous late Palaeozoic marine Konservat-Lagerstätte.     

Presumed postlarval pentacrinoids from the Lower Devonian Hunsrück Slate,Germany

Several tiny crinoids with crowns as small as 1 mm, or less, in width are newly recognized from the Hunsrück Slate of southwestern Germany. The presence of erect arms above an amorphous calyx in some specimens can be inferred. Based on comparison with the size and gross morphology of developmental stages in living crinoids, these tiny Hunsrück crinoids are judged to be at an early postlarval stage that is analogous to the pentacrinoid stage just after development from the stalked, but armless, smaller cystidean larval stage found in both living comatulids and isocrinids. Some of these tiny crinoids have a stalk up to 4 mm long attached to a now pyritized former substrate. Their clustered occurrence suggests gregarious settlement of larvae. Taxonomic identification of these presumed pentacrinoids is not possible, even to the sub‐class level, although they are preserved with larger juveniles of the cladids Propoteriocrinus and Lasiocrinus. These larger juveniles exhibit 3‐D pyritized calcite plates, whereas the probable pentacrinoids appear to be preserved as flattened, micro‐crystalline pyritized dermal tissues that enclosed lightly calcified, porous ossicles. The pentacrinoids were likely buried within weeks or months of hatching, based on developmental stages in similar‐sized living crinoids. These tiny crinoids, presumably pentacrinoids, are a further example of the extraordinarily detailed preservation of delicate tissues in pyrite from the Hunsrück Slate. They are most likely the pentacrinoid stage from one or more of the crinoid taxa (30 genera) present in the Hunsrück Slate. Assuming these are not microcrinoids, they are the first report of pentacrinoids from the fossil record and document that a Palaeozoic sister group to modern crinoids had similar developmental stages.     

A lower Cambrian protoconodont apparatus from the Placentian of southeastern Newfoundland

A cluster of three pyritized, naturally arranged, conoidal sclerites has been found on a bedding surface in the lower Cambrian Chapel Island Formation in southeastern Newfoundland. The elements are about 4 mm in length and are morphologically similar to protoconodonts but neither their original chemical composition nor internal structure is preserved. Arrangement of the elements suggests that they belonged to an apparatus that performed a grasping function. The specimen is described here as ProtohertzinaEfficacynadia n.sp. This is the oldest hitherto described protoconodont apparatus, apart from clusters of Mongolodus described from the lower Cambrian of the Lesser Himalaya. This paper adds to the scant knowledge of early protoconodonts that we consider to be the earliest biomineralized predators.     

Exceptionally preserved lacustrine ostracods from the Middle Miocene of Antarctica: implications for high-latitude palaeoenvironment at 77 degrees south

A newly discovered Konservat-Lagerstätte from the Middle Miocene of the western Olympus Range, Dry Valleys, Antarctica, yields cypridoidean ostracods complete with preserved body and appendages. This is the first record of three-dimensionally fossilized animal soft tissues from the continent. The ostracods are preserved in goethite, secondary after pyrite, representing a novel mode of exceptional preservation. They signal a high-latitude (greater than 77° south) lake setting (Palaeolake Boreas) viable for benthic animal colonization prior to 14 Myr ago. Their presence supports the notion of warmer, tundra-like environmental conditions persisting in the Dry Valleys until the Middle Miocene.     

Preservation of tube feet in an ophiuroid (Echinodermata) from the Lower Devonian Hunsrück Slate of Germany and a redescription of<Emphasis Type="Italic">Bundenbachia beneckei</Emphasis> and<Emphasis Type="Italic">Palaeophiomyxa grandis</Emphasis>

The preservation of non-mineralized tissues in the fossil record is extremely rare. The Lower Devonian Hunsrück Slate of Germany has long been known for the preservation of non-mineralized tissues in pyrite but whether or not these remnants represent true soft tissues has been questioned. This is especially true for struetures visible only on radiographs that are too delicate for excavation by traditional methods. Here we report the discovery of well-preserved pyritized tube feet in six fully prepared specimens of the protasterid brittle starBundenbachia beneckei from the Hunsrück Slate. This discovery represents the first report of fossilized ophiuroid tube feet in the fossil record. The successful excavation of the delicate tube feet was made possible by improved airbrasive techniques developed by German fossil collectors. The relatively large size of the fossil tube feet inBunden-bachia beneckei is consistent with earlier inferences on size based on the presence of large podial basins. Protasterid ophiuroids lack the specialized arm musculature and articulations that provide increased flexibility and strength to the arms of modern ophiuroids with typically reduced tube feet. How-ever, tube foot form and perhaps function inBundenbachia might have been similar to those of living asteroids in which large tube feet are used primarily for locomotion and food-manipulation thus compensating for a lack of specialized arm musculature and articulation. Hence, feeding and life mode of protasterid ophiuroids was not necessarily limited to sedentary, infaunal microphagy as traditionally suggested. Two Hunsrück protasterid ophiuroids,Bundenbachia benecki andPalaeophiomyxa grandis are redescribed and compared.      

New arthropods from the Lower Devonian Hunsru¨ck Slate (Lower Emsian, Rhenish Massif, western Germany)

Four new genera and species of arthropod, Cambronatus brasseli Wingertshellicus backesi Eschenbachiellus wuttkensis and Magnoculus blindi , are described from the Hunsru¨ck Slate (Lower Emsian) of Germany. All four occur in the Wingertshell Member in the vicinity of Bundenbach. They preserve remarkable details of the ventral morphology, including the appendages, as a result of pyritization. In each case the body consists of just two tagmata, a cephalon and a large number of similar trunk somites. Both Cambronatus Wingertshellicus have fluke-like appendages making up a tail fan. The affinities of these arthropods lie with the Crustacea, apart from Magnoculus , which is an arachnomorph, but they do not fall within those clades with modern representatives. They show that morphologies other than those represented by trilobites and modern arthropod groups persisted long after the Cambrian, at least in muddy bottom marine settings.     

Annelids from the Lower Devonian Hunsrück Slate (Lower Emsian, Rhenish Massif, Germany)

Abstract:  Four new genera and species of annelid, Hunsrueckochaeta hohensteini , Ewaldips feyi , Crocancistrius lutzi and Scopyrites magnus , are described from the Hunsrück Slate (Lower Emsian) of Germany, as well as new material of Bundenbachochaeta eschenbachensis   Bartels and Blind, 1995 . The specimens preserve details of the appendages and other aspects of the morphology as a result of pyritization. A phylogenetic analysis using the morphological data matrix of Rouse and Fauchald places four of the five genera basal to the Aciculata; the fifth Ewaldips falls within the Scolecida. The diversity of annelids represented in the Hunsrück Slate is similar to that in the other major Palaeozoic Konservat-Lagerstätten that yield them, including the Cambrian Burgess Shale and the Late Carboniferous Mazon Creek biota.