Palaeontology

ABSTRACT The Guzhangian Weeks Formation (House Range, Utah, USA) contains a virtually unstudied but diverse assemblage of ‘soft-bodied’ organisms. This fauna includes several enigmatic appendages of arthropods that are described in this contribution. Six appendages (two isolated and four paired appendages) are interpreted as frontal appendages of a probably new species of Anomalocaris. They are characterized by a slender morphology, 14 podomeres, ventral spines alternating in size, up to three auxiliary spines per ventral spine, and only two dorsal spines. Another isolated appendage is also tentatively assigned to Anomalocaris, but it exhibits a more robust morphology, a stronger distal tapering, and apparently simple ventral spines, suggesting that it may represent a distinct taxon. These frontal appendages represent the youngest occurrence of anomalocaridids in Laurentia and demonstrate the persistence of older, Burgess Shale-type taxa in the Weeks Formation. An assemblage of four antenniform and six robust and heavily-armed appendages is also described. These are interpreted as the serially arranged, anterior appendages of a single individual of an undetermined arthropod species. This association of three pairs of robust, spiny appendages with two pairs of antenniform structures in a Cambrian arthropod is unique.

ABSTRACT We describe a weakly biomineralized non-trilobite artiopodan arthropod from the Guzhangian Weeks Formation of Utah. Falcatamacaris bellua gen. et sp. nov. is typified by a thin calcitic cuticle, broad cephalon without eyes or dorsal ecdysial sutures, an elongate trunk with distinctively sickle-shaped pleural spines, and a long tailspine with a bifurcate termination. The precise affinities of Falcatamacaris gen. nov. are problematic due to the presence of unique features within Artiopoda, such as the peculiar morphology of the pleural and posterior regions of the trunk. Possible affinities with aglaspidid-like arthropods and concilitergans are discussed based on the possession of 11 trunk tergites, edge-to-edge articulations and overall body spinosity. The new taxon highlights the importance of the Weeks Formation Konservat-Lagerstätte for further understanding the diversity of extinct arthropod groups in the upper Cambrian.

ABSTRACT. Trilobites of the family Lichidae are relatively poorly diversified within the Eifelian mixed siliciclastic-carbonate succession of the southern margin of the Dinant Synclinorium (Belgium). Until now, they were only represented by species belonging to ...

The Authors, on the base of recent international studies and personal observations on the on the field, analyse the importance of the zone of Finale Ligure (Savona Province, Western Liguria, Italy), as crossroad of culture and commerce between distant regions of the Mediterranean area, Italy and Transalpine Europe during prehistoric ages.

Updating Course of SEASTONE ACADEMY, held at the City Council Hall of Pietra Ligure on February 19, 2019.
with the participation of Seastone Riviera - via Nazario Sauro, 196
17027 Pietra Ligure (SV)

Palaeontological material and sites have faced a variety of challenges in the last half century, often due to inadequate legislation from poorly informed legislators designed for very different objects. The most common problematic scenario is for material to be assessed on anthropocentric grounds that are more traditionally applied to archaeological and art objects as 'cultural', and are fundamentally ill-suited for palaeontology. This paper highlights some of the negative consequences of bad legislation in order to explain why it is a global problem that needs to be addressed by the international palaeontological community through direct engagement with legislative bodies.

ABSTRACT Examination of newly collected brachiopods from the Eusebio Ayala Formation of Paraguay reveals the occur-rence of Arenorthis paranaensis sp. nov., Plectothyrella? itacu-rubiensis sp. nov., Hindella sp. and Eostropheodonta conradii (Harrington). Associated graptolites of the N. persculptus Zone indicate that the age of the fossiliferous beds is Hirnan-tian. The overall generic composition of the fauna is similar to that of the atypical Hirnantia Fauna of the Bani Province. The record in Paraguay of Arenorthis, hitherto only known from North Africa, together with species of Plectothyrella? and Eostropheodonta different from those recorded in the Kosov Province, emphasizing the affinities between the Paraguayan fauna and the low-diversity African assemblages. Stratigraphic and faunal evidence indicates that biogeographical links between South America and Africa already existed by the end of the Ordovician when most of the intra-cratonic basins of Gondwana were flooded during the postglacial sea level rise.

The most severe mass extinction among animals took place in the latest Permian (ca. 252 million years ago). Due to scarce and impoverished fossil floras from the earliest Triassic, the common perception has been that land plants likewise suffered a mass extinction, but doubts remained. Here we use global occurrence data of both plant macro- and microfossils to analyse plant biodiversity development across the Permian–Triassic boundary. We show that the plant fossil record is strongly biased and that evidence for a mass extinction among plants in the latest Permian is not robust. The taxonomic diversities of gymnosperm macrofossils and of the pollen produced by this group are particularly incongruent. Our results indicate that gymnosperm macrofossils are considerably undersampled for the Early Triassic, which creates the impression of increased gymnosperm extinction in the latest Permian.

Ichthyosaur fossils are abundant in Lower Jurassic sediments with nine genera found in the UK. In this paper, we describe the partial skeleton of a large ichthyosaur from the Lower Jurassic (lower Sinemurian) of Warwickshire, England, which was conserved and rearticulated to form the centrepiece of a new permanent gallery at the Thinktank, Birmingham Science Museum in 2015. The unusual three-dimensional preservation of the specimen permitted computed tomography (CT) scanning of individual braincase elements as well as the entire reassembled skull. This represents one of the first times that medical imaging and three-dimensional reconstruction methods have been applied to a large skull of a marine reptile. Data from these scans provide new anatomical information, such as the presence of branching vascular canals within the premaxilla and dentary, and an undescribed dorsal (quadrate) wing of the pterygoid hidden within matrix. Scanning also revealed areas of the skull that had been modelled in wood, clay and other materials after the specimen’s initial discovery, highlighting the utility of applying advanced imaging techniques to historical specimens. Additionally, the CT data served as the basis for a new three-dimensional reconstruction of the skull, in which minor damage was repaired and the preserved bones digitally rearticulated. Thus, for the first time a digital reconstruction of the skull and mandible of a large marine reptile skull is available. Museum records show the specimen was originally identified as an example of Ichthyosaurus communis but we identify this specimen as Protoichthyosaurus prostaxalis. The specimen features a skull nearly twice as long as any previously described specimen of P. prostaxalis, representing an individual with an estimated total body length between 3.2 and 4 m.

ABSTRACT The Middle Miocene has been identified as a time of great diversification in modern lineages now distrib-uted in tropical South America, and when basic archetypal traits defining Amazonia appear, including climatic humid conditions, basic floral physiognomy and phylogenetic com-position of modern rainforests. Nonetheless, Middle Miocene localities in South America are poorly known, especially at low latitudes where only one species-rich locality, La Venta in Colombia, has been extensively studied. The present con-tribution describes the mammal fauna of Fitzcarrald, a new Middle Miocene local fauna from western Amazonia in Peru. Fitzcarrald is correlated with the Laventan South American Land Mammal Age based on the presence of taxa defining the 'Miocochilius assemblage zone' in La Venta. The mamma-lian fauna of Fitzcarrald comprises 24 taxa among cingulates, folivores, astrapotheres, notoungulates, litopterns, rodents, odontocetes and a possible marsupial. At this time, tropical South America was characterized by the presence of the Pebas megawetland, a huge lacustrine complex that provided unique ecological and environmental conditions most likely isolating northern South America from southern South America. These isolating conditions might have come to an end with its disappearance in the Late Miocene and the establishment of the subsequent Acre system, the predecessor fluvial system of modern Amazonia. Results of faunistic simi-larity between Fitzcarrald and other Miocene faunas through-out South America support these scenarios. The Fitzcarrald mammal fauna exhibits first appearance datums and last appearance datums of various taxa, showing that tropical South America has played a crucial role in the evolutionary history and biogeography of major clades, and revealing a more complex biological history than previously proposed, based on the record from the southern cone of the continent.