Mesacanthus is a common and speciose genus of acanthodian fish from Lower Old Red Sandstone and Middle Old Red Sandstone assemblages (representing the Lower Devonian and Middle Devonian respectively) and is well represented in many palaeoichthyology collections in the UK. Based upon descriptions given during the 19th century, specimens of the genus Mesacanthus from the Orcadian Basin and Midlan...

Complete, exceptionally-preserved skulls of the Permian lungfish Persephonichthys chthonica gen. et sp. nov. are described. Persephonichthys chthonica is unique among post-Devonian lungfishes in preserving portions of the neurocranium, permitting description of the braincase of a stem-ceratodontiform for the first time. The completeness of P. chthonica permits robust phylogenetic analysis of th...

During the Late Devonian Biodiversity Crisis, the primary driver of biodiversity decline was the dramatic reduction in speciation rates, not elevated extinction rates; however, the causes of speciation decline have been previously unstudied. Speciation, the formation of new species from ancestral populations, occurs by two primary allopatric mechanisms: vicariance, where the ancestral populatio...

Plant fossils in the Early Devonian Beartooth Butte Formation (Wyoming, USA) are colonized by microconchid encrusters which are found on several plant taxa, at two fossil localities in the formation, and whose tube coil diameters range from 230 to 1170 lm. Colonization is densest on broad Drepanophycus devonicus stems where microconchid individuals encompassing broad size ranges co-occur in clo...

A nearly complete spider spinneret was found in Middle Devonian rocks (about 385 to 380 million years old) near Gilboa, New York. This is the earliest evidence yet discovered for silk production from opisthosomal spigots, and therefore for spiders. Two previously known Devonian fossils described as spiders lack any apomorphies of the order Araneae and are probably not spiders. The spigots of th...

Citation: Lupoi JS, Fritz LP, Parris TM, Hackley PC, Solotky L, Eble CF and Schlaegle S (2017) Assessment of Thermal Maturity Trends in Devonian–Mississippian Source Rocks Using Raman Spectroscopy: Limitations of Peak-Fitting Method. Front. Energy Res. 5:24. doi: 10.3389/fenrg.2017.00024 assessment of Thermal Maturity Trends in Devonian–Mississippian source rocks Using raman spectroscopy: limit...

Carbon isotope (N13C) analyses of marine carbonates spanning the Silurian^Devonian transition are compared from three richly fossiliferous, well-dated sequences in North America. The three sections, in the central Appalachian Mountains (West Virginia), Great Basin (Nevada), and the southern Mid-continent (Oklahoma), reveal positive N13C shifts beginning in the late Pridoli and reaching peak val...

Mass extinctions have altered the trajectory of evolution a number of times over the Phanerozoic. During these periods of biotic upheaval a different selective regime appears to operate, although it is still unclear whether consistent survivorship rules apply across different extinction events. We compare variations in diversity and disparity across the evolutionary history of a major Paleozoic...

A single leafy stem from the Middle or lowermost Upper Devonian Campo Chico Formation, Sierra de Perija, western Venezuela, is the first record of the important Devonian herbaceous lycophyte Leclercqia from South America, usually considered as part of western Gondwana. The seemingly cosmopolitan distribution of this genus is discussed in relation to coeval assemblages and palaeocontinental reco...

Hyneria lindae, gen. et sp. nov., is a large rhizodontid rhipidistian fish from the Upper Devonian (Oswayo Formation) of Pennsylvania. It shows a remarkable similarity to the intermediate stages that must have preceded the first true Amphibia. The similarity is due to the parallel evolution of rhizodontid Rhipidistia and the Amphibia from a common stock in the Middle or early Late Devonian. POS...