The Avalon assemblage of Newfoundland, Canada contains abundant fossils of enigmatic soft-bodied Ediacaran organisms, many with remarkable preservation. One of the most numerically dominant groups of organisms in the assemblage is the Rangeomorpha, a frondose clade characterized by self-similar, repeating branching architecture known worldwide from rocks of Ediacaran age. Variations in branching characters and gross morphology have historically been used to divide this group, but there has been little consistency in taxonomic approach to the Rangeomorpha, concomitantly there are conflicting opinions that have resulted in some overlapping taxonomic diagnoses. Here we investigate one such taxonomic dispute, the Beothukis/Culmofrons problem. The two genera were recently synonymized into Beothukis based on the assertion that some characters were of different taxonomic rank than others. Subsequent debate has focused on which taxonomic characters displayed by the Rangeomorpha should be used for genus- and species-level subdivision. To test the validity of using continuous versus discrete characters in rangeomorph taxonomy we use a combination of morphometrics and statistical analysis to identify natural clusters within our specimen dataset which was collected from Beothukis sensu lato including material that was, until recently, attributed to Culmofrons. The results of the cluster assignment validates the differentiation between Beothukis mistakensis and Beothukis (Culmofrons) plumosa, but cannot—in isolation—be used to determine at what taxonomic rank that distinction should be made. We demonstrate a considerable degree of variation within Beothukis and Culmofrons, which has not yet been recorded for unifoliate rangeomorph taxa.

Well-preserved tracks of the wild boar Sus scrofa are described from the Matalascañas Trampled Surface (MTS) in the upper Pleistocene aeolian basal unit of the El Asperillo Cliff, Huelva (southwestern Spain). These are the first published tracks of suid pigs in the fossil record, here formally described as Suidichnus galani igen. and isp. nov. A revision of valid artiodactyl ichnogenera is provided for comparison. The large size of wild boar found in the Late Pleistocene of Spain contradicts the general trend towards smaller size known for the evolution of the species and the Bergmann's ecogeographical rule for the extant subspecies. In the present case, the remarkable large size that can be reached by these tracks is discussed as an ecomorphological adaptation of wild boars to either resource bonanza, and/or predation pressure during the Last Interglacial. The large S. scrofa scrofa identified in MTS corresponds to some of the earliest evidences known to this subspecies in Iberia.

During the late Cambrian–Early Ordovician interval the predominant non-microbial reef builders were sponges or sponge-like metazoans. The lithological and faunal composition of Cambro-Ordovician sponge-dominated reefs have previously been analyzed and reviewed. Here we take the relationship between reef aggregation pattern at reef to seascape scale into account, and look for changes during the Early–Middle Ordovician interval, in which metazoans became dominant reef builders. In a comparison of sponge-rich reefs from eight sites of the Laurentia paleocontinent three different seascape level reef growth patterns can be distinguished: (1) mosaic mode of reef growth, where reefs form a complex spatial mosaic dependent on hard substrate; (2) episodic mode, where patch reefs grew exclusively in distinct unconformity bounded horizons within non-reefal lithological units that have a much larger thickness; and (3) belt-and-bank mode, where reefs and reef complexes grew vertically and laterally as dispersed patches largely independent from truncation surfaces. The distinct modes of growth likely represent specific reef forming paleocommunities, because they differ in content and abundance of skeletal metazoan framebuilders, bioturbation intensity of non-skeletal reef sediment matrix, and in association of reef growth with underlying hard substrate. We suggest, based on a review of Laurentian reef occurrences, that the mosaic mode dominated in Early Ordovician strata and that the dominance shifted toward the belt and bank mode from Middle Ordovician strata onward.

Free-living forms of crustose coralline algae (rhodoliths) accumulate on shallow-water marine shelves in many regions worldwide. They form their own benthic habitats termed ‘rhodolith beds’ and their deposits are well preserved in the rock record. Characteristics of rhodolith deposits can be used to interpret ancient water depths, light levels, and water energies. Accurate paleoceanographic interpretations rely on large-scale, detailed studies of living rhodolith beds, but these studies are scarce. Spencer Gulf in South Australia has the largest living rhodolith beds in southeastern Australia (∼ 3,000 km²). Documentation of these rhodolith deposits includes facies analysis, coralline algal taxonomy, characterization of growth forms and morphometrics, and integration with oceanographic data. Extensive oceanographic data and hydrodynamic modeling enable comparisons between rhodolith morphologies and bottom water energies with unprecedented accuracy. Rhodolith deposits in the gulf are intermixed with carbonate sands and muds under diverse hydrodynamic conditions, with current speeds up to 1.04 m s^–1. At least five coralline algal genera construct rhodoliths in Spencer Gulf. Growth forms include fruticose, lumpy, and warty. Rhodolith morphologies imply that water energy is not the only thing affecting rhodolith movement and growth; rhodoliths can also be shifted by fish and invertebrates. Linear regression models in this study evaluate relationships between rhodolith morphometrics (mean diameter, sphericity, and branch density) and maximum bottom water speeds in Spencer Gulf and their results support the idea that water energy is not a major control on rhodolith morphology under these water energy conditions. Previous studies have revealed that the relationship between rhodolith morphologies and water energy levels is complicated and many authors have cautioned to not rely solely on rhodolith morphologies to interpret paleoceanographic conditions. Results of this study demonstrate that accurate paleoceanographic interpretations cannot be made based on rhodolith morphologies alone, but should also include sedimentology, coralline taxonomy, and associated biota.