نتایج جستجو برای: jurassic
تعداد نتایج: 4540 فیلتر نتایج به سال:
Two new docodontans, Simpsonodon sibiricus sp. nov. and Hutegotherium yaomingi gen. et sp. nov., and a new specimen of Itatodon tatarinovi Lopatin et Averianov, 2005 are described from the Middle Jurassic (Bathonian) Itat Formation of Krasnoyarsk Territory in West Siberia, Russia. A new phylogenetic analysis, incorporating 37 dental and mandibular characters and 18 docodontan and outgroup taxa ...
It updates the biostratigraphic refinement in the Indian Mesozoics with focus on the Triassic in Spiti, Jurassic in Kachchh, and Cretaceous in Kachchh and Cauvery. As an example, the ammonoid stratigraphic zonation in Kachchh basin inclusive of the new Oxfordian zones, as also the origin of the basin are developed at length. Also are touched upon the salient pre-sequence Paleozoic features as b...
Remains of theropod dinosaurs are very rare in Northern Germany because the area was repeatedly submerged by a shallow epicontinental sea during the Mesozoic. Here, 80 Late Jurassic theropod teeth are described of which the majority were collected over decades from marine carbonates in nowadays abandoned and backfilled quarries of the 19th century. Eighteen different morphotypes (A-R) could be ...
The fossil record of cuttlefish, squid and octopus has received relatively little attention. Among malacologists, the opinion is widespread that these mainly softbodied coleoids have a poor fossil record. However, thanks to Konservat-Lagerst tten such as the Early Jurassic Posidonian Shales of Holzmaden (Germany), the Middle Jurassic La-Voulte-sur-Rh ne (France) and the Late Jurassic Limestones...
Upper Jurassic and Lower Cretaceous bashal strata are preserved in a discontinuous belt along the inboard margin of the Alexander-WrangelliaPeninsular terrane (AWP) in Alaska and western Canada, on the outboard margin of terranes in the Canadian Cordillera accreted to North America prior to Late Jurassic time, and along the Cordilleran margin from southern Oregon to southern California. Nearly ...
Ceratopsia is one of the best studied herbivorous ornithischian clades, but the early evolution of Ceratopsia, including the placement of Psittacosaurus, is still controversial and unclear. Here, we report a second basal ceratopsian, Hualianceratops wucaiwanensis gen. et sp. nov., from the Upper Jurassic (Oxfordian) Shishugou Formation of the Junggar Basin, northwestern China. This new taxon is...
The Rochechourt impact structure in south-central France, with maximum diameter of 40–50 km, has previously been dated to within 1% uncertainty of the Triassic– Jurassic boundary, at which time ~30% of global genera became extinct. To evaluate the temporal relationship between the impact and the Triassic–Jurassic boundary at high precision, we have re-examined the structure’s age using multicol...
Owing to the assumed lack of deep-sea macrofossils older than the Late Cretaceous, very little is known about the geological history of deep-sea communities, and most inference-based hypotheses argue for repeated recolonizations of the deep sea from shelf habitats following major palaeoceanographic perturbations. We present a fossil deep-sea assemblage of echinoderms, gastropods, brachiopods an...
BACKGROUND Anomopterellidae was originally classified as a family within the Evanioidea, and later lowered to a subfamily, Anomopterellinae, of Praeaulacidae. Up to date, only Rasnitsyn 1975, with four species, was assigned to Anomopterellinae. Due to their special wing venation and their metasomal attachment similar to those known in Evanioidea, the systematic position of Anomopterellinae in E...
A series of spectacular discoveries have transformed our understanding of Mesozoic mammals in recent years. These finds reveal hitherto-unsuspected ecomorphological diversity that suggests that mammals experienced a major adaptive radiation during the Middle to Late Jurassic. Patterns of mammalian macroevolution must be reinterpreted in light of these new discoveries, but only taxonomic diversi...
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