نتایج جستجو برای: late devonian

تعداد نتایج: 197086  

2015
Błażej Błażejowski Piotr Gieszcz Carlton E. Brett Marcin Binkowski

This study presents a detailed analysis of an exceptionally well-preserved articulated specimen of the trilobite Trimerocephalus from the Late Devonian of the Holy Cross Mountains in Poland. X-ray microtomography reveals the oldest direct evidence for a moulting episode known from the fossil record. The process of moulting as well as associated features observed in the investigated specimen are...

Journal: :Austrian Journal of Earth Sciences 2022

Abstract The low-grade metamorphic early Paleozoic basement of the Veitsch area presents a wide variety sedimentary facies domains. first domain consists thick metadacites Middle Ordovician age (Blasseneck Porphyroid), overlain by fine-grained metaclastics Rad Formation (Late to Silurian) and Devonian limestones calcitic marbles (Kaiserstein Kaskögerl Formation, respectively). Rhyolitic dacitic...

2012
JOSEPH A. CARUSO ALEXANDRU M. F. TOMESCU

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...

Journal: :Science 1982
D M Raup J J Sepkoski

A new compilation of fossil data on invertebrate and vertebrate families indicates that four mass extinctions in the marine realm are statistically distinct from background extinction levels. These four occurred late in the Ordovician, Permian, Triassic, and Cretaceous periods. A fifth extinction event in the Devonian stands out from the background but is not statistically significant in these ...

Journal: :International Journal of Earth Sciences 2021

Abstract The eastern Anti-Atlas of Morocco represents one the most completely exposed and perfectly documented biostratigraphic records entire Devonian worldwide. Paleogeographically it is clearly differentiated into shallow basins, pelagic platforms, land areas which are newly defined illustrated, from top Middle Devonian, other middle Famennian as two characteristic intervals. dominant paleog...

Journal: :Science 1989
W A Shear J M Palmer J A Coddington P M Bonamo

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...

2015
Jason S. Anderson Tim Smithson Chris F. Mansky Taran Meyer Jennifer Clack

The lack of fossil tetrapod bearing deposits in the earliest Carboniferous ('Romer's Gap') has provoked some recent discussions regarding the proximal cause, with three explanations being offered: environmental, taphonomic, and collection failure. One of the few, and earliest, windows into this time is the locality of Blue Beach exposed in the Tournaisian deposits at Horton Bluff lying along th...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید