The phylogenetic position of scorpions within the Chelicerata has been the subject of much debate in recent years (e.g. Weygoldt & Paulus, 1979; Bergström, 1980; Van der Hammen, 1989; Shultz, 1990; Starobogatov, 1990), but it revolves around one primary question: are scorpions part of a monophyletic Arachnida, or are they “merostomes” which exhibit a terrestrial grade of existence? Inclusion of...

Pentastomids (tongue worms) are worm-like arthropods known today from ∼140 species [1]. All but four are parasitic on vertebrates. Their life cycle typically involves larval development in an intermediate host followed by maturation in the respiratory tract of a definitive terrestrial host. Fossil pentastomids are exceedingly rare and are known only from isolated juveniles [2-6]. The identity o...

Much of what we know about the history of Earth’s climate derives from the chemistry of carbonate minerals in the sedimentary record. The oxygen isotopic compositions (dO) of calcitic marine fossils and cements have been widely used as a proxy for past seawater temperatures, but application of this proxy to deep geologic time is complicated by diagenetic alteration and uncertainties in the dO o...

The Hoseiba Member, an Early Silurian basal mature hot shale of the Akkas Formation (Silurian) consists about 80% Paleozoic hydrocarbon potential system, it is organic-rich with total organic carbon up to 16% as main source for gas resources in Iraq. rocks that are penetrated deep wells western Iraqi desert such Akkas-1, Qaim-1, and Khleisia -1, which distributed due paleo uplift restricted reg...

Members of the family Laccophyllidae are small, solitary rugose corals with stratigraphic ranges from Silurian to Permian. Among the laccophyllids, axial ends of major septa are united in an aulos and dissepiments may be absent or present. Minor septa can be contratingent and sometimes are small or in some genera are absent. Septa and aulos may be thick or thin. In this study, Famennian rugose...

Taking the Ordovician Wufeng Formation-Silurian Longmaxi Formation as an example of shale gas development in Southern Sichuan Basin and its periphery. According to guiding “Lithofacies paleogeographical research mapping compilation can be a guide for geological survey” methods area selection evaluation, lithofacies paleogeography basic conditions this have been carefully studied, potential area...