A new species of Hyattechinus (Echinoidea) from the type Devonian of the United Kingdom and implications for the distribution of Devonian proterocidarid echinoids

Many of the most diverse clades of Late Palaeozoic echinoids (sea urchins) originated in the Devonian period. Our understanding of diversity dynamics of these Late Palaeozoic clades are thus informed by new systematic descriptions of some of their earliest members. The Proterocidaridae are a diverse and morphologically distinct clade of stem group echinoids with flattened tests and enlarged adoral pore pairs, which are first known from the Upper Devonian. We herein report on a new species of Hyattechinus, Hyattechinus anglicus n. sp., from the Upper Devonian of the North Devon Basin, Devon, UK. This is the first Devonian Hyattechinus known from outside of the Appalachian Basin, USA, and provides novel information regarding the palaeogeographic and stratigraphic distribution of proterocidarids in Late Devonian times. We additionally update the stratigraphic distribution of Devonian Hyattechinus from the Appalachian Basin, following recent biostratigraphic resolution of their occurrences. Hyattechinus appears to have been present in the Rheic echinoderm fauna during Late Devonian times, and comparison of the palaeoenvironmental setting of Hyattechinus anglicus with that of other Hyattechinus from the Famennian of the Appalachian Basin suggests that the genus may have preferred siliciclastic settings. Furthermore, this new taxon increases the diversity of echinoids from the Upper Devonian of Devon to three species

Cretaceous conifers and angiosperms from the Bonarelli Level, Reassessment of Massalongo's plant fossil collections of "Monte Colle", Lessini Mountains, northern Italy

International audienc

New insights into the morphology and taxonomy of the Cretaceous conifer Frenelopsis based on a new species from.the Albian of San Just, Teruel, Spain

Frenelopsis justae sp. nov. is reported from the middle – lower upper Albian Escucha Formation of San Just, Teruel province, Spain. It shows micro-morphological features hitherto undescribed in the genus Frenelopsis including: (1) individual stomatal apparatus comprised of only three subsidiary cells; (2) clusters of 2–3 stomatal apparatus sharing a single subsidiary cell; (3) stomatal rows that bifurcate; and (4) an internal, cylindrical, cell layer preserved between the adaxial and abaxial cuticles. The morphology in the genus is reinterpreted, the long leaf sheath consisting of the proximal abaxial surface of 2–3 fused leaves lacking visible sutures with short distal free parts. Therefore, the generic diagnosis is emended, and new microscopic features added. We show that the appearance, morphology and structure of the leaf surfaces, free leaf tips, and stomatal apparatus are highly variable and regard them as innovation hot-spots in Frenelopsis species. We emphasize the need to perform thorough quantitative analysis of Frenelopsis morphology, including description of metrics variance, to improve our knowledge of its taxonomy, phenotypical plasticity and evolutionary trends.Centre National de la Recherche ScientifiqueCentre National de la Recherche Scientifique (CNRS) [UMR 5276]Universite Lyon 1Ministerio de Economia y Competitividad of the Spanish Government [CGL-2013-42643 P, CGL2015-60805-P, CGL2015-68363-P]AGAURAgencia de Gestio D'Ajuts Universitaris de Recerca Agaur (AGAUR) [2014SGR-251]Catalan Research Authorit

Cretaceous conifers and angiosperms from the Bonarelli Level; Reassessment of Massalongo's plant fossil collections of Monte Colle, Lessini Mountains, northern Italy

The lost plant fossil and fish locality of \u201cMonte Colle\u201d, near the village of Bolca, Verona province, northern Italy has been considered to be of Eocene age since the middle of the nineteenth century. However, upon re-examination of the plant fossils, especially the specimens of Aularthrophyton Massalongo, which closely resemble the fossil conifer Frenelopsis Schenk, led us to suspect that a Cretaceous age was more probable. Fieldwork to re-evaluate the local stratigraphy, and the identification of the radiolarians Crucella cachensis Pessagno and Patellula helios (Squinabol) within the matrix of surviving hand specimens, all definitively show that the fossil bed actually belongs to the uppermost Cenomanian Bonarelli Level. With this revised age, we properly describe the gross morphology of the surviving plant specimens and reinterpret their identifications and affinities. Frenelopsis petraepurae comb. nov., Geinitzia sp., and a single angiosperm leaf type are described and the consequences for nomenclature outlined. Comparisons with coeval Cretaceous plant taxa are also discusse

Local-scale analysis of plant community from the Early Cretaceous riparian ecosystem of Hautrage, Belgium

Diversity properties and relative taxon abundance are explored to describe plant community local-scale spatial and temporal patterns during four ecological stages from the middle Barremian continental aquatic ecosystem of Hautrage, Mons basin, western Belgium. Taxon co-occurrence and correlations of taxon abundance are also analyzed to describe the main patterns of plant association within each stage and through time. Diversity, relative taxon abundance and taxonomic inventory greatly vary laterally and between ecological stages. Two of these stages show gradients in taxon richness and abundance reflecting probable edge effects. A reconstruction of the plant community evolution based on these four stages plus seven previously reported stages reveal a plant community mainly composed of the conifers Arctopitys, Brachyphyllum, Frenelopsis, and Pagiophyllum, and the ferns Gleichenites and Phlebopteris, maintained through time. Two main taxon association patterns are observed over space and time: 1) Arctopitys and Phlebopteris, and 2) Brachyphyllum, Gleichenites, Pagiophyllum. Conifer type 1, Elatides and Sphenopteris appear to have been spatially associated, whereas inverse relations between Cladophlebis and Phlebopteris and between Onychiopsis and Sphenopteris reflect possible niche overlap and competitive exclusion pressures. Three different successional stages are identified by the proportion of herbaceous and woody taxa and the presence/absence of Frenelopsis. Frenelopsis was a dominant taxon in mature community stages probably forming closed canopies, and having a negative effect on richness and abundance of other taxa. Our results evidence four intense and two less intense fire events through the series, suggesting that wildfires played an important role in the ecological succession of the plant community of Hautrage. Weichselia reticulata most probably played a key role in early successional stages, contributing in the regeneration of plant communities after wildfire disturbance events

Perforocycloides nathalieae new genus and species, an unusual Silurian cyclocystoid (Echinodermata) from Anticosti Island, Québec, Canada

Cyclocystoids are a poorly known, rare, extinct class of bi-facially flattened, disc shaped echinoderms, ranging from the Middle Ordovician to the Early Carboniferous. Articulated cyclocystoids are relatively common in the Ordovician but are rarer in younger strata. Here we describe Perforocycloides nathaliae new genus and species, from the early Silurian of Anticosti Island, Québec, Canada, the first articulated cyclocystoid from the Silurian of North America. This taxon is distinguished from other cyclocystoids by the number of variably sized marginal ossicles, the lack of interseptal plates, and the novelty of pores located in the distal part of the sutures between adjacent marginals on the dorsal surface. These dorsal intermarginal sutural pores led to canals which penetrated the contiguous area of the lateral surface of the marginals and emerged on the ventral surface between the cupules of adjacent marginals. These dorsal intermarginal sutural pores/canals appear to be unique to Perforocycloides and whilst their function is speculative, they provided some form of communication between the dorsal disc and the distal side of the ventral marginals/cupules. Perforocycloides most closely resembles the Ordovician–Silurian genus Zygocycloides, suggesting that this genus may have diversified more widely during the Silurian than previously reported. A review of global Silurian cyclocystoid distribution suggests taxa were geographically confined and that greatest diversity appears to have been located within Baltica. However, it also demonstrates our current limited knowledge. No specimens have been recorded from Gondwana (e.g. Africa, Australia, South America), Siberia, and North and South China, nor are any specimens known confidently anywhere from Přidolí strata.This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made