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Chitony z piasków tortońskich Kotliny Sądeckiej

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W piaskach tortońskich odsłaniających się w Niskowej koło Nowego Sącza znaleziona została obfita fauna chitonów. Reprezentowanych jest wśród niej 5 gatunków należących do 5 różnych rodzajów. Najliczniejszym jest Acanthochitona sandeciana n.sp.
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The first discoveries of European pit vipers (Crotalinae gen. et sp. indet. A and B) are reported from the Ukrainian Miocene (MN 9a) locality of Gritsev. Based on perfectly preserved maxillaries, two species closely related to pit vipers of the 'Agkistrodon' complex are represented at the site. It is suggested that the European fossil representatives of the 'Agkistrodon' complex are Asiatic immigrants. Pit vipers probably never expanded into the broader areas of Europe during their geological history.
Comparison of cuticular ultrastructure in Antarctidromia inflata Förster, 1985 from the Miocene Cape Melville Formation on King George Island, Antarctica, with that of the confamilial, extant Homolodromia paradoxa A. Milne Edwards, 1880 suggests that the more rigid carapace of the fossil form results from a relatively thicker, more strongly calcified exocuticle. Epicuticle, exocuticle, and endocuticle are all recognizable on the fossils; however, adherence of the epicuticle to the counterpart may result in misinterpretation of the fine sculpture on the carapace. Absence of dissolution features in the endocuticle confirm conclusions, based upon completeness of remains, that the specimens of Antarctidromia inflata represent corpses, not molts.
Recent molecular studies have recognized the skunks (Mephitinae) to be the sister taxon - of a clade comprising the Procyonidae and Mustelidae. These findings are inconsistent with the traditional placement of the skunks among mustelids, which is based on morphological evidence from extant taxa. This paper reports on a well-preserved cranium of a young individual, recovered from the middle Miocene deposits (MN 7+8, about 11-12 Ma) of Steinheim am Albuch, Germany. The fossil is the holotype of Palaeomephitis steinheimensis Jäger, 1839, which is here recognized as a senior subjective synonym of Trochotherium cyamoides Fraas, 1870 (consequently, Palaeomephitis Jäger, 1839 is a senior subjective synonym of Trochotherium Fraas, 1870). The specimen is identified as the oldest and most primitive mephitine cranium known to date, approaching the primitive morphology for the Mephitinae. It exhibits a combination of mephitine (accessory middle-ear chamber, lateral swelling of the squamosal) and mustelid (mustelid suprameatal fossa) synapomorphies, corroborating the view that skunks are derived from a mustelid ancestor. Its auditory bulla shows a slightly inflated and relatively large caudal entotympanic, which indicates that the uninflated and relatively small caudal entotympanics of adult mephitines, as well as their hypertrophied ectotympanics, are not primitive (as hitherto assumed) but derived, providing a synapomorphy that supports a sister-group relationship between the Mephitinae and Lutrinae.
The size and morphological characteristics of a skull of an arctomorph carnivoran mammal from Mouillac (old collection of the Phosphorites du Quercy, of unknown age) in France closely match those of the holotype of the earliest known procyonid Pseudobassaris riggsi and another skull referred to this species, both from old collections of the Phosphorites du Quercy (Caylus and Mouillac), probably earliest Late Oligocene in age. The skull is more primitive in morphology than those of Pseudobassaris riggsi and every other known procyonid, approaching a hypothetical primitive procyonid morphotype. The only, but methodologically fundamental, departure from this morphotype is the lack of the procyonid suprameatal fossa, which is the crucial synapomorphy of the family Procyonidae. To explain the phylogenetic and taxonomic status of the arctomorph represented by the skull, three competing hypotheses are put forward. Hypothesis A, which considers the arctomorph as an individual of Pseudobassaris riggsi, assumes that the procyonid suprameatal fossa first appeared in a common ancestor of Pseudobassaris and other procyonids but was still of variable occurence within Pseudobassaris riggsi. Hypothesis B, which proposes the arctomorph as a member of a new Pseudobassaris species ancestral to Pseudobassaris riggsi, concludes that the procyonid suprameatal fossa arose in Pseudobassaris riggsi and in the Procyonidae independently, excluding Pseudobassaris from the procyonids. Hypothesis C, which recognizes the arctomorph as a representative of a new species of a new genus of the paraphyletic procyonid stem group, presumes that the procyonid suprameatal fossa originated in a common ancestor of Pseudobassaris and other procyonids after the new genus had become detached from the ancestral stock of the Procyonidae.
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