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A detailed exploration of growth and trunk segmentation of the oryctocephalid trilobite, Duyunaspis duyunensis Chang & Chien in Zhou et al. 1977, from the lower Cambrian (Stage 4, Series 2) Balang Formation in western Hunan Province, South China, is presented. Because of the excellent preservation, the complete post‐protaspid ontogenetic series from merapsid degree 0 to the holaspid phase is described...
The 87Sr/86Sr isotope ratio has been widely used as a physical tool to date and correlate carbonate successions due to the long Sr residence time in comparison with the ocean mixing time. If this method works on oceanic successions, marginal basins may show different Sr isotope records in comparison with the coeval ocean one due to sea‐level variations, continental run‐off and restricted water exchanges...
A macroinvertebrate assemblage has been studied from the Thin Nodular Limestones Member (TNL) of the Fonte Coberta section (Lusitanian Basin, Portugal), giving special attention to its trace fossils. The assemblage was studied to analyse the influence of the Toarcian Oceanic Anoxic Event (T‐OAE) on the macroinvertebrate community. The TNL consists of thin alternations of marl/limestone and nodular...
Here we report the discovery of an Early Carboniferous (Late Visean) 3D cephalopod beak displaying significant similarity to the lower beak of Recent coleoids. It was uncovered in a fragmentarily preserved, longiconic shell from the Moorefield Formation in Arkansas, USA. This shell comprises a fractured 29‐mm‐long body chamber having a maximum diameter of ~14 mm and showing an indistinct pro‐ostracum‐like...
Well‐preserved juvenile specimens of the orthotetide brachiopod Coolinia pecten (Linnaeus, [Linnaeus, C., 1758]) from the Silurian of Gotland, Sweden, demonstrate evidence of a planktotrophic larval habit. Larval shell morphology indicates the absence of a pedicle sheath: this character is otherwise typical of derived billingsellides, strophomenides and productides, which form the conventional strophomenide...
Dimpled phosphatic microspherules, contradictorily associated with conodonts, are widely distributed in strata ranging in age from the Cambrian to Carboniferous. These microspherules have attracted much attention from palaeobiologists and were suggested to be ‘conodont pearls’, ‘conodont otoliths’ or ‘fish otoliths’ due to their similar chemical composition and co‐occurrence with conodonts or fish...
Apportioning trace fossils to producers is significant for palaeoecological and palaeoenvironmental studies. A tracemaker is usually attributed through the comparison of the morphology of the trace to the body plans of modern and extinct animals. However, hypotheses of tracemaker identifications may be tested with the use of further methods. This contribution aims to evaluate the potential tracemakers...
In this study, the evolution of the long bones in a group of basal synapsids was analysed, belonging to the caseids (Synapsida, Caseasauria, Caseidae), a crucial Palaeozoic group of terrestrial vertebrates. During their evolutionary history, caseids transitioned from small faunivorous tetrapods such as Eocasea martini (reaching ~20 cm total length), to gigantic herbivores such as Cotylorhynchus hancocki...
Iberosuchus macrodon is a Cenozoic crocodyliform interpreted as a terrestrial, cursorial form. To assess whether this adaptation was accompanied by a high growth rate and an elevated resting metabolic rate (two features commonly attributed to several terrestrial Triassic Crocodylomorpha based on histology), we studied bone histology in the femora of two specimens attributed to I. macrodon. Beyond...
Phanerozoic mass extinctions have been studied primarily by analysing global diversity patterns compiled from the published literature. However, such compilations are beset by problems of incorrect correlation, imprecise age assignments and changing taxonomy. An alternative approach is to analyse mass extinctions by the ‘best sections’ method. This method identifies abundantly fossiliferous, well‐studied,...
The study of evolution in a palaeontological context is chiefly the study of change in shape and form. This requires data sets that quantify morphology and morphological variation. Historically morphology has been described using discrete characters or more recently using various morphometric approaches. Elliptical Fourier analysis (EFA) is an approach to quantifying morphology that results in the...
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