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We redescribe the holotype and only known specimen of the early eureptile Coelostegus prothales from the Upper Carboniferous of the Czech Republic using photogrammetric CT scanning and a virtual 3D rendition of its skull bones. New information is available on several skull and lower jaw bones, including the postorbital, supratemporal, tabular, postparietal, angular, and prearticular. The new data also permit the correct identification of previously undetected or misidentified elements (e.g., supratemporal; quadratojugal; angular). We provide an amended diagnosis of Coelostegus and a new reconstruction of the skull in dorsal and lateral views. To- evaluate the affinities of Coelostegus, we code this taxon in two recently published taxon-character matrices. Parsimony and Bayesian analyses do not permit firm conclusions on the phylogenetic position of Coelostegus or, indeed, the status and extrinsic relationships of protorothyridid amniotes. Coelostegus emerges either as the sister taxon to the recently redefined Diapsida (Araeoscelidia; Varanopidae; Parareptilia; Neodiapsida), as one of the most basal protorothyridids, or as a derived stem-group amniote in various parsimony-based analyses, or as the basalmost protorothyridid in one Bayesian analysis, with protorothyridids forming a paraphyletic array relative to Diapsida. We review the cranial similarities and differences between Coelostegus and other protorothyridid genera and discuss the implications that various phylogenetic results have for our understanding of early amniote relationships.

The taxonomically diverse terrestrial tetrapod fauna from the late Mississippian East Kirkton Limestone includes the earliest known members of stem Amphibia and stem Amniota. Here we name and describe a new East Kirkton tetrapod with an unusual hind limb morphology reminiscent of that of several stem- and primitive crown amniotes. It displays a unique ilium with two slender and elongate processes and a 5-digit pes with a long, stout metatarsal IV and a greatly elongate digit IV. The new taxon broadens our knowledge of East Kirkton tetrapods, adding to the remarkable diversity of their hind limb constructions, functional specializations, locomotory modes, and adaptations to a wide variety of substrates. An unweighted character parsimony analysis places the new taxon in a polytomy alongside some other Carboniferous groups. Conversely, weighted parsimony and Bayesian analyses retrieve it among the earliest diverging stem amniotes, either as the basalmost anthracosaur or within a clade that includes also Eldeceeon and Silvanerpeton, crownward of an array of chroniosaurs plus anthracosaurs.

The purpose of this paper is twofold: firstly, it aims to analyze the philosophical debate between Gadamer and Blumenberg concerning the notion of secularization, which, in the author's view, has received less attention than it deserves; secondly, it intends thereby to shed light on an ontological ambiguity in Gadamer's hermeneutics, unintentionally detected by Blumenberg in his reply to Gadamer's review of The Legitimacy of the Modern Age. The importance of the paper is both historical-philosophical and theoretical: it spells out different aspects of a philosophical discussion whose relevance concern not only the secularization debate, but more generally the philosophy of history and the role of metaphors in understanding. The most relevant original contribution consists in the usage of Blumenberg's notion of background metaphorics as a tool for interpreting the role of the notion of history of effects in Gadamer's hermeneutics.