Latest Precambrian to Early Palaeozoic biosphere evolution triggered changes in early diagenesis and carbonate precipitation which fed back to biodiversity through colonization of hard substrates. Progressive increase in the depth and intensity of bioturbation and bio‐irrigation lowered the zone of early carbonate cementation in the uppermost sediment column.
Palaeontological data are key elements for inferring ancestral character states and the assembly of character complexes, but cephalopod fossils preserving soft tissues are very rare. The exceptionally well‐preserved, unique specimen of Jurassic Proteroctopus ribeti Fischer & Riou from the Lagerstätte of La‐Voulte‐sur‐Rhône (c. 165 Ma, France) is one of the few fossil octopod related taxa, but is rarely considered in evolutionary studies.
A nearly complete radula with seven elements per row preserved inside of an isolated, bivalved, calcitic lower jaw (= aptychus) of the Late Jurassic ammonite Aspidoceras is described from the Fossillagerstätte Painten (Bavaria, southern Germany). It is the largest known ammonite radula and the first record for the Perisphinctoidea. The multicuspidate tooth elements (ctenodont type of radula) present short cusps.
We examined bristle‐like appendages on the tail of the Early Cretaceous basal ceratopsian dinosaur Psittacosaurus with laser‐stimulated fluorescence imaging. Our study reveals previously unknown details of these structures and confirms their identification as integumentary appendages. For the first time, we show that most bristles appear to be arranged in bundles and that they exhibit a pulp that widens towards the bristle base.
During the late Palaeozoic ice age (LPIA), ice‐proximal marine regional communities record contrasting responses to climate change compared to ice‐distal communities. However, there is still much to be understood in distal regions in order to fully understand the palaeobiological consequences of the LPIA. Here, were analyse brachiopod and bivalve environmental preferences along the bathymetric gradient during a major glacial event and the subsequent non‐glacial interval in western Argentina.
Malacostracan crustaceans of the fossil order Pygocephalomorpha are conspicuous elements in brackish to freshwater faunas in the upper Carboniferous of Laurentia and lower Permian of Gondwana. A pronounced sexual dimorphism is recognizable within its members, with Pygocephalomorpha females bearing oöstegites: modified epipodites that hold a brood pouch where the eggs develop until juvenile stage, with no planktonic dispersal of larvae. The preservation of oöstegites is quite rare and is described here for the first time from the American continents.
Omnidens is a large feeding apparatus composed of circlets of teeth, first documented from the early Cambrian of China. Originally interpreted as the oral cone of a radiodontan, it was later reinterpreted as the introvert of a priapulan. In both cases the Omnidens mouthparts underpinned estimates of gigantic (c. 2 m) body size.
Sauropodomorpha represents an important group of Mesozoic megaherbivores, and includes the largest terrestrial animals ever known. It was the first dinosaur group to become abundant and widespread, and its members formed a significant component of terrestrial ecosystems from the Late Triassic until the end of the Cretaceous. Both of these factors have been explained by their adoption of herbivory, but understanding the evolution of sauropodomorph feeding has been hampered by the scarcity of biomechanical studies.
Marine crocodylomorphs were particularly abundant in Europe during the Middle Jurassic, but were very scarce in Africa. New finds of thalattosuchian cranial remains in Morocco suggest that this scarcity is probably related to poor sampling rather than original diversity. These remains pertain to the coastal thalattosuchians, the teleosauroids, and particularly to the clade grouping the blunt‐toothed ‘Steneosaurus’ obtusidens and the genus Machimosaurus. A new tribe is erected grouping these two taxa: Machimosaurini.
The origin of tetrapods is one of the key events in vertebrate history. The oldest tetrapod body fossils are Late Devonian (Frasnian–Famennian) in age, most of them consisting of rare isolated bone elements. Here we describe tetrapod remains from two Famennian localities from Belgium: Strud, in the Province of Namur, and Becco, in the Province of Liège. The newly collected material consists of an isolated complete postorbital, fragments of two maxillae, and one putative partial cleithrum, all from Strud, and an almost complete maxilla from Becco.
