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Large, unwebbed bird and bird-like footprints from the Mesozoic and Cenozoic: a review of ichnotaxonomy and trackmaker affinity Lethaia (IF 1.5) Pub Date : 2021-12-29 Martin G. Lockley, Nasrollah Abbassi, Charles W. Helm
The Mesozoic and Cenozoic track record of large birds (avian theropods) with footprint lengths (FL) > 10.0 cm is quite limited, whereas small tracks (FL < 10.0 cm) are abundant from the Early Cretaceous onwards. This large versus small threshold value is consistent with the track record of extant birds among which only ˜10% are large, and so is scaled appropriately to Class Aves. The proportion of
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Bioerosion and palaeoecological association of osteophagous insects in the Maastrichtian dinosaur Arenysaurus ardevoli Lethaia (IF 1.5) Pub Date : 2021-12-21 Penélope Cruzado-Caballero, José I. Canudo, Silvina De Valais, Jaime Frigola, Eduardo Barriuso, Josep Fortuny
Bioerosions produced by the osteophagous diet of animals that fed on dinosaur bones are very scarce in the European fossil record. Herein we present bioerosion on hadrosaurid remains from the Maastrichtian Tremp Formation of the Pyrenean Basin, which is only the second such case recorded from the Iberian-Occitan Plate besides a sauropod from the Jurassic-Cretaceous of Valencia. The hadrosaurid fossil
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Ferruginous casts of bromalites in kaolin beds: microbial ferrihydrite-goethite transformation as early stage taphonomy in lacustrine and riparian sediments Lethaia (IF 1.5) Pub Date : 2021-12-21 Paul L. Broughton
Two spatiotemporally distant deposits in western North America on differing sides of the K-Pg boundary are recognized to have accumulated innumerable ferruginous faecal-like specimens consisting of 3-D casts suspended in kaolin clay fills of lacustrine and riparian areas proximal to fluvial channels. Evidence presented interprets these specimens as organic in origin, consisting of coprolites and other
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A sting in the tale of Parioscorpio venator from the Silurian of Wisconsin: is it a cheloniellid arthropod? Lethaia (IF 1.5) Pub Date : 2021-12-16 Simon J. Braddy, Jason A. Dunlop
Parioscorpio venator Wendruff et al., 2020a from the early Silurian Waukesha biota of Wisconsin, USA, interpreted as the earliest scorpion, then a basal euarthropod, is reinterpreted here as a cheloniellid-like arthropod with large raptorial appendages. The diversity of Cheloniellida Broili, 1932 is reviewed. Drabovaspis complexa Chlupáč, 1963, from the Upper Ordovician Letná Formation of Czechia,
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Ecology, morphology and ontogeny of Paleolimulus kunguricus—a horseshoe crab from the Kungurian (Cisuralian) of the Cis-Urals, Russia Lethaia (IF 1.5) Pub Date : 2021-10-13 Serge V. Naugolnykh, Russell D. C. Bicknell
Paleolimulids represent a group of fossil horseshoe crabs that are morphologically comparable to the extant limulids. Recent work has highlighted that, contrary to traditional opinions, Paleolimulidae has a limited taxonomic and morphological diversity at the species and generic level. In the light of this new perspective, it is imperative that material documenting novel facets of species within this
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A new vertebrate fossil-bearing layer in the Rhætelv Formation (Kap Stewart Group) of central East Greenland: evidence of a Hettangian marine incursion into the continental Jameson Land Basin Lethaia (IF 1.5) Pub Date : 2021-10-12 Lars B. Clemmensen, Sofie Lindström, Octávio Mateus, Malte Mau, Jesper Milàn, Dennis V. Kent
The Kap Stewart Group (Rhaetian-Sinemurian, Triassic–Early Jurassic) of the Jameson Land Basin in central East Greenland has traditionally been regarded as a strictly continental unit with delta and perennial lake sediments. New finds of plesiosaur bone remain in a thin storm deposited sandstone bed in the middle part of the Rhætelv Formation of the Kap Stewart Group, however, indicates a likely period
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Biofilm harvesters in coastal settings of the early Palaeozoic Lethaia (IF 1.5) Pub Date : 2021-10-12 Nora Noffke, M. Gabriela Mángano, Luis A. Buatois
The ichnogenera Syringomorpha and Daedalus are here interpreted as products of infaunal biofilm harvesters. This study investigated: (1) Syringomorpha nilssoni and Syringomorpha isp. from the Cambrian Series 2-Miaolingian Campanario Formation, northwest Argentina; and (2) Daedalus halli from the Floian Grès et Schistes de la Cluse de l'Orb Formation, Montagne Noire, France. Syringomorpha nilssoni occurs
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Biomineralization of primary carbonate cements: a new biosignature in the fossil record from the Anisian of Southern Italy Lethaia (IF 1.5) Pub Date : 2021-10-11 Adriano Guido, Matteo Sposato, Giuseppe Palladino, Alessandro Vescogni, Domenico Miriello
Biomineralization is a generic term used to indicate biological-mediated mineral formation. In carbonate mineralization, nucleation of crystals can be: (1) controlled directly by the organisms, like in the skeletal formation of most metazoans; (2) induced by microbial communities, by indirect precipitation mediated by their metabolic activities; or (3) influenced by organic matter decay, with mineral
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Discovery of plant cuticles in phyllite, late Pennsylvanian Southern Anthracite Field, eastern Pennsylvania, USA: a new research resource? Lethaia (IF 1.5) Pub Date : 2021-10-11 Erwin L. Zodrow, José A. D'Angelo
We report a small number of well preserved Late Pennsylvanian plant fossils physically associated with an 8-cm-long assumed anthracitic axis on one of the larger rock slabs (phyllite) described by Leo Lesquereux from the Southern Anthracite Field, USA. The fragmentary fossils, not larger than 1.6 mm, resemble microscopically ‘fossilized-cuticles’. Additionally, observed are 10–28 μm diametric bodies
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A demineralized osteostracan fossil from the Silurian Kalana Lagerstätte of Estonia: revealing its internal anatomy and uncovering a unique type of fossilization Lethaia (IF 1.5) Pub Date : 2021-10-11 Oive Tinn, Liisa Lang, Tiiu Märss, Signe Vahur, Kalle Kirsimäe
The anatomy of a dorsal head shield of an agnathan fossil Kalanaspis delectabilis, belonging to class Osteostraci from the Aeronian (early Silurian) Kalana Lagerstätte of Estonia was studied using the X-ray computer-tomography. Scanning exposed shallow superficial relief on the dorsal surface of the head shield, which unmasked the internal anatomy of the specimen. The Kalanaspis fossil displays a mosaic
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High-resolution Pliocene–Pleistocene calcareous nannofossil distribution and palaeoenvironmental changes in the northwest Nile Delta, Egypt Lethaia (IF 1.5) Pub Date : 2021-09-17 Sherif Farouk, Sreepat Jain, Mohammad Abd-Elazez, Tamer El Shennawy, Fatma Shaker
The Pliocene–Pleistocene sequences in the Nile Delta are of immense economic significance due to their hydrocarbon potential. Hence, a better understanding of the time-calibrated basinal palaeoenvironmental changes is essential to improve the hydrocarbon recovery. A total of 182 sub-surface samples from the Sapphire-DC well in the offshore north-western part of the Nile Delta were analysed to reveal
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First fossil evidence of leaf-feeding caterpillars from India and their feeding strategies Lethaia (IF 1.5) Pub Date : 2021-09-17 Taposhi Hazra, Robert A. Spicer, Manoshi Hazra, Subhankar Kumar Sarkar, Teresa E.V. Spicer, Subir Bera, Mahasin Ali Khan
Evidence of predatory marks on fossil leaf remains provides a unique window into ecological and evolutionary associations of the past, but finding both damage and the phytophagous insects causing that damage pattern in the same fossil specimen is a very rare phenomenon. Normally, caterpillars have little fossilization potential because of their delicate structure, but here, we present the first fossil
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Recurring taphonomic processes in the carnivoran-dominated Late Miocene assemblages of Batallones-3, Madrid Basin, Spain Lethaia (IF 1.5) Pub Date : 2021-09-02 David M. Martín-Perea, Maria S. Domingo, Enrique Cantero, Lloyd A. Courtenay, Alberto Valenciano, Lucía R. Sualdea, Juan Abella, Jorge Morales
Carnivoran-dominated fossil sites are scarce in the fossil record but provide precious information on the diversity and ecology of past carnivoran guilds. The Cerro de los Batallones sites host the oldest carnivoran-dominated assemblages, with the highest carnivoran abundances observed in the fossil record. Batallones-3 (Late Miocene, Madrid Basin, Spain) hosts three discrete, carnivoran-dominated
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Shell microstructures of latest Permian Rugosochonetidae (Brachiopoda): evidence from SEM- and CT-scanned shell materials Lethaia (IF 1.5) Pub Date : 2021-09-02 Yang Zhang
Microscopic perforations in brachiopod shells, such as endopunctae, pseudopunctae, extropunctae, aditicules and epipunctae, have various biological functions. Based on excellently preserved material, aditicules are found to be widely developed in the Fusichonetes and Neochonetes, and setae-bearing aditicules are shown to exist in rugosochonetid brachiopods for the first time. SEM and Micro-CT images
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The concept of ‘heteromorph ammonoids’ Lethaia (IF 1.5) Pub Date : 2021-08-30 Neil H. Landman, Marcin Machalski, Christopher D. Whalen
‘Heteromorph ammonoids’ encompass all ammonoid species whose shapes do not conform to a closely coiled planispiral shell. The term is useful as a broad description for such ammonoids. However, as a concept, ‘heteromorph ammonoids’ no longer has any scientific value or explanatory power. Although such ammonoids have traditionally been considered aberrant forms, they represent instead an integral part
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First discovery of the soft-body imprint of an Oligocene fossil squid indicates its piscivorous diet Lethaia (IF 1.5) Pub Date : 2021-08-10 Aleksandr A. Mironenko, Maxim S. Boiko, Alexandre F. Bannikov, Alexander I. Arkhipkin, Viacheslav A. Bizikov, Martin Košťák
The first well-preserved soft-body imprint of a fossil squid was discovered from the Lower Oligocene of the Krasnodar region, Russia. The squid is perfectly preserved, with many details of its body available for study, such as imprints of eyes and head, a pair of statoliths, jaws, and stomach contents. Statoliths of this squid are the first finds of in situ statoliths in fossil non-belemnoid coleoids
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Coprolites in natural traps: direct evidence of bone-eating carnivorans from the Late Miocene Batallones-3 site, Madrid, Spain Lethaia (IF 1.5) Pub Date : 2021-07-27 Juan Abella, David M. Martín-Perea, Alberto Valenciano, Daniel Hontecillas, Plini Montoya, Jorge Morales
We describe two carnivoran coprolites found in the pseudokarst natural carnivore trap of Batallones-3, from the Late Miocene of Spain. The larger one, comprising multiple indistinguishable fragments of broken and corroded bones, indicates that the producer of the dropping might have been highly capable of crushing the softer parts of large bones. On the other hand, the smaller one shows several relatively
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Morphological diversity and disparity in trilobite cephala and the evolution of trilobite enrolment throughout the Palaeozoic Lethaia (IF 1.5) Pub Date : 2021-07-22 María Gabriela Suárez, Jorge Esteve
Morphology permits the extracting of information to study patterns of disparity and diversity of a particular group of animals through time. Enrolment is a characteristic behaviour of trilobites, having been first recorded in the Cambrian and continued until their demise at the end of Permian mass extinction. Morphological trends related to enrolment strategies have been documented previously but are
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Conch geometry, ontogeny and dimorphism in the Early Bajocian ammonoid Stephanoceras from Normandy, France Lethaia (IF 1.5) Pub Date : 2021-07-22 Michel Schmidt, Dieter Korn
A large suite of specimens belonging to the Early Bajocian Stephanoceras from Évrecy (Normandy, France) displays wide variation in conch and sculpture. The quantitative analysis of the conch geometry and its ontogeny on the basis of more than 50 sectioned specimens reveals major problems in the separation of species within the assemblage; clear morphological boundaries between possible species cannot
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Diversity, palaeoecology and palaeoenvironmental significance of the Eocene chondrichthyan assemblages of the Bolca Lagerstätte, Italy Lethaia (IF 1.5) Pub Date : 2021-07-22 Giuseppe Marramà, Giorgio Carnevale, Jürgen Kriwet
Over the last few years, the morphology, taxonomy and systematics of the cartilaginous fish taxa of the two main sites of the Bolca Lagerstätte, Italy, (Pesciara and Monte Postale sites) have been extensively discussed in a series of papers, resulting in a complete revision of this neglected component of the Eocene Tethyan ichthyofauna. Here, we provide a comprehensive overview of the diversity, palaeoecology
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The functional performance of productidine brachiopods in relation to environmental variables Lethaia (IF 1.5) Pub Date : 2021-07-21 Rylan V. Dievert, Murray K. Gingras, Lindsey R. Leighton
Fossils are useful as palaeoenvironmental indicators when evaluated using large occurrence and lithology association data sets and/or functional morphology. However, when functional morphology is invoked on an ad hoc basis there exists a risk of circular reasoning. Performance spaces/landscapes constructed using biomechanical experiments can be used to tie performance to morphology quantitatively.
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Late Anisian microbe-metazoan build-ups in the Germanic Basin: aftermath of the Permian–Triassic crisis Lethaia (IF 1.5) Pub Date : 2021-07-21 Yu Pei, Jan-Peter Duda, Jan Schönig, Cui Luo, Joachim Reitner
The so-called Permian–Triassic mass extinction was followed by a prolonged period of ecological recovery that lasted until the Middle Triassic. Triassic stromatolites from the Germanic Basin seem to be an important part of the puzzle but have barely been investigated so far. Here, we analysed late Anisian (upper Middle Muschelkalk) stromatolites from across the Germanic Basin by combining petrographic
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Eurypterid morphology and implications for ecdysis and evolutionary longevity Lethaia (IF 1.5) Pub Date : 2021-06-13 Danita S. Brandt
Three morphological characters of eurypterids (Arthropoda, Chelicerata) have been suggested as potentially affecting the ease with which this group experienced ecdysis and, therefore, the likelihood of mortality during moulting: (1) the presence or absence of appendages bearing numerous or long spines; (2) the width of the swimming appendage; and (3) the type of prosoma ventral plate. If ecological
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Morphological and compositional analyses of coprolites from the Upper Cretaceous Bauru Group reveal dietary habits of notosuchian fauna Lethaia (IF 1.5) Pub Date : 2021-06-11 Fábio A. de Oliveira, Rodrigo M. Santucci, Carlos Eduardo M. de Oliveira, Marco B. de Andrade
The fluvial deposits of the Adamantina Formation (Upper Cretaceous, Bauru Group) have produced a rich fossil vertebrate record of fishes, amphibians, lizards, snakes, turtles, dinosaurs and mammals. However, the record of notosuchians (Crocodylomorpha) is remarkable in terms of both diversity and number of findings. Here, we report a large number of new coprolites found in association with skeletons
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Vauxiids as descendants of archaeocyaths: a hypothesis Lethaia (IF 1.5) Pub Date : 2021-06-09 Cui Luo, Aihua Yang, Andrey Yu. Zhuravlev, Joachim Reitner
Archaeocyaths were one of the major animal groups contributing to the Cambrian Explosion. Despite an overall poriferan appearance of their hypercalcified skeletons, they exhibit a number of peculiar features such as the presence of septa and an absence of spicules. This sets archaeocyaths apart from general trends in early poriferan evolution. Fossils recently discovered from the early Cambrian Guanshan
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Newly discovered Wuchiapingian to Olenekian conodonts from the Longgar area, southern Lhasa Terrane and their palaeobiogeographical implications Lethaia (IF 1.5) Pub Date : 2021-06-09 Guichun Wu, Zhansheng Ji, Gary G. Lash, Jianxin Yao, Shaowen Zhang, Yongxi Li
Biostratigraphical, geochemical and palaeomagnetic studies have demonstrated that the Lhasa Terrane occupied a low-latitude southern hemisphere region during Late Permian to Early Triassic time. However, the palaeogeographical relationship of the South Qiangtang and the Lhasa terranes remains a topic of debate. The principal dispute focusses are on whether the Bangong-Nujiang Suture Zone (BNSZ) separating
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Identification of conodont fossils in pelagic deep-sea siliceous sedimentary rocks using laboratory-based X-ray computed microtomography Lethaia (IF 1.5) Pub Date : 2021-06-09 Shun Muto, Shinsuke Yagyu, Satoshi Takahashi, Masafumi Murayama
This study provides a description of a method of observing conodont elements in pelagic deep-sea sedimentary rocks (chert and siliceous claystone) using laboratory-based X-ray computed microtomography for the first time. By careful preparation of conodonts embedded in rock samples and processing of tomographic sections, we managed to produce 3D images with high enough spatial resolutions for identification
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New data on the palaeosteohistology and growth dynamic of the notosuchian Araripesuchus Price, 1959 Lethaia (IF 1.5) Pub Date : 2021-05-17 María L. Fernández Dumont, Maria E. Pereyra, Paula Bona, Sebastián Apesteguía
Notosuchian crocodyliforms represent an intriguing group since they are mainly terrestrial forms and therefore with completely different lifestyles than extant crocodylian, which is reflected in their particular skeletal anatomy. Although there are some inferences in the literature related to the palaeoecology of notosuchian, little is known about their biology (e.g. metabolism, growth dynamics). The
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Predator–prey interactions among Pliocene molluscs from the Tjörnes Peninsula, Iceland; across the trans-Arctic invasion Lethaia (IF 1.5) Pub Date : 2021-05-13 Samuel H. Neely, Patricia H. Kelley, Michelle M. Friedman
The fossil record provides a long-term perspective to better understand the impacts of species invasions in their environmental contexts. Temporal analyses of predator–prey interactions from the Tjörnes deposits, Iceland, track naticid gastropod drilling predation across the trans-Arctic invasion (TAI: ~3.5 Ma). These deposits represent three zones subdivided into 25 marine fossil-bearing beds that
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Heliolitid corals and their competitors: a case study from the Wellin patch reefs, Middle Devonian, Belgium Lethaia (IF 1.5) Pub Date : 2021-05-10 Jan J. Król, Julien Denayer, Pawe? Wolniewicz, Miko?aj K. Zapalski
Wellin patch reefs are small Upper Eifelian build?ups within the fine?grained argillaceous limestone of the Hanonet Formation. Whereas the reefs themselves are not well exposed, their fossil assemblage is accessible in the hills near the town of Wellin, approximately 40\xA0km SE of Dinant in Belgium. It is especially rich in massive stromatoporoids, heliolitids and other tabulate corals. They exhibit
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Silurian stratigraphy and graptolite faunas of the Mora 001 and Solberga 1 drill cores, Siljan District, central Sweden Lethaia (IF 1.5) Pub Date : 2021-05-10 Jörg Maletz
The Mora 001 and Solberga 1 drill cores provide the best available overview on the early Silurian (Llandovery, Rhuddanian to Telychian) graptolite succession available for the Siljan Ring impact structure of central Sweden. The Solberga 1 succession includes a nearly complete graptolite succession from the Pernerograptus revolutus Biozone (late Rhuddanian) to the Oktavites spiralis Biozone (late Telychian)
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A contiguous record of the SPICE event, sea-level change and the first appearance of Fenghuangella laevis in Shandong Province, North China Lethaia (IF 1.5) Pub Date : 2021-05-10 Guangying Ren, Fanwei Meng, Mikaela A. Pulsipher, James D. Schiffbauer, Jinliang Yuan, Yan Zhao, Ying Guo, Jian Gao, Chao Chang
Achieving accurate chronostratigraphical correlation between late Cambrian sections in North China and sections from elsewhere in the world has been a long-standing problem, largely owing to a lack of preserved or identified biostratigraphical marker fauna. Here, we examine trilobite occurrences, the sequence of facies and lithological change, and carbon and oxygen isotopes from the carbonate sequence
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Palaeoecology and taphonomy of a middle Miocene domical cheilostome bryozoan, Siwa Oasis, the northern Western Desert of Egypt Lethaia (IF 1.5) Pub Date : 2021-04-16 Magdy El Hedeny, Andrej Ernst, Ahmed El-Sabbagh, Mohammed Rashwan, Saleh Al Farraj, Ghada Al Basher, Heba Mansour
A primary study of bioerosional structures and skeletobionts associated with an almost monotypic assemblage of free-lying bryozoan colonies of Celleporaria? sp., from the middle Miocene succession of the Siwa Oasis, Egypt, revealed four groups of encrusters (serpulids, sheet-like cheilostome bryozoans, balanoid barnacles and oysters) and eight different ichnotaxa. Undersides of the colonies have basal
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The evolution of thecideide microstructures and textures: traced from Triassic to Holocene Lethaia (IF 1.5) Pub Date : 2021-04-02 Maria Simonet Roda, Erika Griesshaber, Lucia Angiolini, David A.T. Harper, Ulrich Jansen, Maria Aleksandra Bitner, Daniela Henkel, Eloy Manzanero, Tamás Müller, Adam Tomašových, Anton Eisenhauer, Andreas Ziegler, Wolfgang W. Schmahl
Thecideide brachiopods are an anomalous group of invertebrates. In this study, we discuss the evolution of thecideide brachiopods from the Triassic to the Holocene and base our results and conclusions on microstructure and texture measurements gained from electron backscatter diffraction (EBSD). In fossil and Recent thecideide shells, we observe the following mineral units: (1) nanometric to small
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The influence of volcanic activity and trophic state on plant taphonomic processes in Triassic lacustrine-deltaic systems of western Gondwana Lethaia (IF 1.5) Pub Date : 2021-03-09 Tomás Ezequiel Pedernera, Adriana Cecilia Mancuso, Eduardo Guillermo Ottone
The impact of volcanic activity and trophic state on the preservation of plant remains from two Triassic palaeolake deposits in western Gondwana is investigated. Six taphonomic modes are identified for the Potrerillos–Cacheuta sequence and the Los Rastros Formation, along with proposed taphonomic pathways for each mode. The taphonomic pathways were compared with those proposed for the Agua de la Zorra
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A Lower Cretaceous Lagerstätte from France: a taphonomic overview of the Angeac‐Charente vertebrate assemblage Lethaia (IF 1.5) Pub Date : 2021-01-23 Lee Rozada, Ronan Allain, Romain Vullo, Jean Goedert, Dominique Augier, Amandine Jean, Jonathan Marchal, Claire Peyre de Fabrègues, Martin Qvarnström, Rafael Royo‐Torres
Terrestrial ecosystems from the Lower Cretaceous of Europe and bonebeds formed in swampy environments are poorly known. The Berriasian‐early Valanginian Angeac‐Charente site in France represents an example of both. Nine field campaigns have yielded thousands of fossils of over a hundred taxa, including 16 taxa from vertebrate macroremains with numerous trample and crocodile bite marks; 22 taxa from
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Planktonic foraminifera assemblages from the Brazil–Malvinas Confluence: palaeoceanographic implications of sub-surface temperature reconstructions in the western South Atlantic Lethaia (IF 1.5) Pub Date : 2021-02-07 Natalia García Chapori, Cecilia Laprida
Planktonic foraminifera census data have been widely used to reconstruct changes in ocean ecosystems as well as ocean chemistry and circulation through calibration functions. Here we analyse new core-top census data from 22 sites in the western South Atlantic, improving the geographical coverage and spatial resolution of the environmental gradients from the region covered by the Brazil–Malvinas Confluence
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Sclerobionts associated with Orbiramus from the Early Ordovician of Hubei, China, the oldest known trepostome bryozoan Lethaia (IF 1.5) Pub Date : 2021-01-27 Junye Ma, Paul D. Taylor, Caroline J. Buttler
In addition to a marked rise in marine biodiversity, the Ordovician witnessed the most profound increase in the complexity of marine ecosystems in the history of the earth, including the expansion of tiering and enhanced biotic interactions. In order to understand these changes, it is important to study palaeoecological relationships among organisms at the commencement of the Great Ordovician Biodiversification
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Foraging flatworms and roundworms caught in the act: examples from a Middle Triassic mud flat in Germany Lethaia (IF 1.5) Pub Date : 2020-12-24 Dirk Knaust
Exceptionally preserved remains of Platyhelminthes (flatworms) and Nematoda (roundworms) are closely associated with ammonoids, nautiloids and asteroids in Middle Triassic carbonates of the Upper Muschelkalk Group in Germany. Although soft-bodied organisms occur in different parts of the succession, the reported examples indicate foraging and a possible scavenging relationship of these worms and their
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Cirrus versus radice: a brief study of confused crinoid terminology Lethaia (IF 1.5) Pub Date : 2020-12-22 Stephen K. Donovan
Comatulid and isocrinid crinoids have flexible, motile attachment structures called cirri that articulate synarthrially. In other crinoids, structures that are superficially similar, yet non-motile, articulating symplectially or synostially and in some taxa branched, are referred to as radices or radicles. To refer to a ‘root’ structure as a cirrus just because it is unbranched is erroneous. Obviously
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An Early Triassic small shelly fossil-style assemblage from the Virgin Limestone Member, Moenkopi Formation, western United States Lethaia (IF 1.5) Pub Date : 2020-12-05 Vivienne Maxwell, Ben Thuy, Sara B. Pruss
Small shelly fossils (SSFs) are minute fossils moulded or replaced by apatite, and less commonly, other minerals like glauconite and iron oxides. This taphonomic mode is best known from Cambrian deposits, though some occurrences occur across geological time. Instances of small shelly-style preservation were found in insoluble residues from the Lower Triassic Virgin Limestone Member exposed in southern
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The shell fabric of Palaeozoic brachiopods: patterns and trends Lethaia (IF 1.5) Pub Date : 2020-12-05 Facheng Ye, Claudio Garbelli, Shuzhong Shen, Lucia Angiolini
The varied microstructures of brachiopod biominerals represent a robust archive to understand the evolution and adaptations of marine calcifiers in time. Therefore, a detailed study of the shell microstructure of Cambrian to Devonian brachiopods from Iran is here presented. The shell of 38 brachiopod species, representatives of 22 families and nine orders, has been analysed using scanning electron
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Early Palaeozoic Discinocarina: a key to the appearance of cephalopod jaws Lethaia (IF 1.5) Pub Date : 2020-12-03 Aleksandr A. Mironenko
Cephalopoda is the only class of molluscs in which virtually all its modern representatives have a pair of powerful jaws. There is little doubt that jaws have contributed to the evolutionary success of cephalopods, but their origin still remains a mystery. Though cephalopods appeared at the end of the Cambrian, the oldest unequivocal jaws have been reported to date from the Late Devonian, though they
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ʻConodont pearlsʼ do not belong to conodonts Lethaia (IF 1.5) Pub Date : 2020-12-01 Annalisa Ferretti, Daniele Malferrari, Martina Savioli, Teresa Siepe, Luca Medici
We investigated the mineralogical and chemical signatures of enigmatic microspherules commonly recovered in conodont residues and referred to in literature as ‘conodont pearls.’ Comparison between these ‘pearls,’ associated conodonts and other phosphatic skeletal elements present in the same stratigraphical level was run in an effort to reveal any possible relation between ‘conodont pearls’ and the
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The oral apparatus composition of the Early Carboniferous elictognathid conodont ‘Siphonodella’ Lethaia (IF 1.5) Pub Date : 2020-12-01 Przemysław Świś, Jerzy Dzik
Conodont P1 elements of ‘Siphonodella’ are the most important guide fossils for the Tournaisian and topmost Famennian. Hypotheses on the origin and evolution of the elictognathid (‘Siphonodella’) clade are based exclusively on the morphology of one pair of elements in the 15 element apparatus, because of difficulties with its reconstruction. An unusually rich sample taken from the Kowala Quarry in
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From lagoons to mud mounds: palaeoecology of the Givetian to Frasnian stromatoporoids from the Holy Cross Mountains, Poland Lethaia (IF 1.5) Pub Date : 2020-11-27 Paweł Wolniewicz
Stromatoporoids are an extinct group of Palaeozoic sponges that dominated the Devonian carbonate buildups. Although their general environmental requirements are known, their palaeoecological preferences at genus level are less studied. Seven stromatoporoid associations are distinguished within the Givetian (Middle Devonian; associations 1–3) and Frasnian (Upper Devonian; associations 4–7) of the Holy
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Evaluating the role of coastal hypoxia on the transient expansion of microencruster intervals during the early Aptian Lethaia (IF 1.5) Pub Date : 2020-11-26 Alexander Hueter, Stefan Huck, Ulrich Heimhofer, Stéphane Bodin, Stefan Weyer, Klaus P. Jochum, Yvonne Roebbert, Adrian Immenhauser
Worldwide, a growing number of modern coastal marine ecosystems are increasingly exposed to suboxic- or even anoxic conditions. Low seawater oxygen levels trigger significant ecosystem changes and may result in mass mortality of oxygen-sensitive biota. The applicability of observations from recent (anthropogenically influenced) suboxic coastal settings to fossil anoxic shallow-marine environments is
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Crowded Trichophycus ichnofabrics in the early Ordovician successions of central Iran: insight into the Ordovician radiation Lethaia (IF 1.5) Pub Date : 2020-11-05 Aram Bayet-Goll, Alfred Uchman, Mehdi Daraei, Carlos Neto de Carvalho
The Tremadocian-to-Floian siliciclastic deposits of the Shirgesht Formation in the Kalmard Block of central Iran show abundant occurrences of the mid-tier Trichophycus venosus, a common ichnotaxon in the archetypical Cruziana ichnofacies. This trace fossil records a considerable increase in exploitation of offshore infaunal ecospace in comparison with older formations. Here, Trichophycus is relatively
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New dinosaur, crocodylomorph and swim tracks from the Late Jurassic of the Lusitanian Basin: implications for ichnodiversity Lethaia (IF 1.5) Pub Date : 2020-11-04 Diego Castanera, Elisabete Malafaia, Bruno C. Silva, Vanda F. Santos, Matteo Belvedere
New dinosaur (theropod and sauropod), crocodylomorph and swim tracks from Upper Jurassic units of the Lusitanian Basin, housed at the Sociedade de História Natural in Torres Vedras, are here described. They were collected from three different geological formations, the Praia da Amoreira‐Porto Novo (upper Kimmeridgian) and the Alcobaça (Kimmeridgian‐lower Tithonian) formations in the Consolação Sub‐basin
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Diversity and palaeoecology of Australia's southern-most sauropods, Griman Creek Formation (Cenomanian), New South Wales, Australia Lethaia (IF 1.5) Pub Date : 2020-10-29 Timothy G. Frauenfelder, Nicolás E. Campione, Elizabeth T. Smith, Phil R. Bell
Predominately, occurances of Australian sauropods from the Early to mid-Cretaceous of Queensland and Western Australia, lie between ~45° and 55°S palaeolatitude. The Cenomanian Griman Creek Formation, which straddles the New South Wales–Queensland border, preserves arguably one of the richest Cretaceous terrestrial faunas in Australia. Although sauropod postcranial elements are notably absent or as
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The Anthropozoic era revisited Lethaia (IF 1.5) Pub Date : 2020-10-27 Valentí Rull
This paper explains in some detail the poorly known proposal of Stoppani (1873) regarding the Anthropozoic era, whose beginning was defined by the first traces of human presence on Earth. This author set the stratigraphical bases for the definition of the ‘human era’, but the proposal had two main weaknesses: the dismissal of biological evolution and the lack of an absolute chronology. Further developments
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Carboniferous–Permian conodonts and the age of the lower Cutler Group in the Bears Ears National Monument and vicinity, Utah, USA Lethaia (IF 1.5) Pub Date : 2020-10-22 Adam K. Huttenlocker, Charles M. Henderson, David S. Berman, Scott D. Elrick, Amy C. Henrici, W. John Nelson
The Carboniferous–Permian (C–P) Cutler Group in southeastern Utah archives large-scale environmental changes along multiple facies belts, including major sea-level changes and continental aridification that intensified into earliest Permian times. Nevertheless, the stratigraphical position of the C–P boundary within the Cutler Group has been poorly constrained, until now. Here, we report the first
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Ediacaran macrofossils prior to the ~580 Ma Gaskiers glaciation in Newfoundland, Canada Lethaia (IF 1.5) Pub Date : 2020-09-11 Alexander G. Liu, Benjamin H. Tindal
Macrofossils of the inferred protist‐grade organism Palaeopascichnus linearis occur stratigraphically beneath glacial diamictites of the ~580 Ma, Gaskiers‐equivalent, Trinity ‘facies’ of the Rocky Harbour Formation on the Bonavista Peninsula of Newfoundland, Canada. These fossils significantly pre‐date previously reported macrofossils from Avalonia and extend the taphonomic window for moldic preservation
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Predatory drill holes in the oldest thyasirid bivalve, from the Lower Jurassic of South Germany Lethaia (IF 1.5) Pub Date : 2020-09-10 Baran Karapunar, Winfried Werner, Franz T. Fürsich, Alexander Nützel
Drill holes provide valuable information about palaeoecological interactions in fossil ecosystems, but the Jurassic drill‐hole record is scarce. We report circular drill holes in the infaunal bivalve Eothyasira antiqua(Münster in Goldfuss) from the Pliensbachian grey shales of the Amaltheenton Formation of Franconia, southern Germany. The outcrop of the Amaltheenton Formation at Buttenheim yields a
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From fossil associations to ecological communities: a case study from the ‘Cipit boulders’ of the upper Ladinian–lower Carnian St Cassian Formation, Dolomites, NE Italy Lethaia (IF 1.5) Pub Date : 2020-09-10 Francisco Sánchez‐Beristain, Joachim Reitner
The definition of a fossil ecological community from fossil associations has always been problematic. Determining coevality of the members of a fossil association has posed one of the most ravelling problems in this matter. However, in case of relicts of fossil reefs, this problem seems, to some extent, solvable due to the frequency of fossil findings in life position. In addition, the interaction
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A tholichthys‐like larva (Teleostei, Percomorpha) from the Eocene of Northern Caucasus, Russia Lethaia (IF 1.5) Pub Date : 2020-09-10 Giorgio Carnevale, Alexandre F. Bannikov
A morphologically bizarre fish larva is described based on a single specimen from Eocene (Bartonian) locality of Gornyi Luch, Krasnodar Region, Northern Caucasus, SW Russia. The fossil larva described here was collected form the Kuma Horizon and inhabited an open marine setting with bottom waters characterized by poorly oxygenated conditions, where it was associated with abundant pelagic fish taxa
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Moulting in the Cambrian oryctocephalid trilobite Arthricocephalites xinzhaiheensis from Guizhou Province, South China Lethaia (IF 1.5) Pub Date : 2020-09-09 Yifan Wang, Jin Peng, Qiujun Wang, Rongqin Wen, Hui Zhang, Guangying Du, Yunbin Shao
It is important to understand moulting behaviours in trilobites through different growth stages. Most studies have focused on patterns of moulting in trilobites based on a few exuviae. The present study is based on 177 disarticulated specimens of Arthricocephalites xinzhaiheensis from the Balang Formation (Cambrian Series 2, Stage 4, Guizhou Province, South China). The abundance of disarticulated assemblages
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Structural, chemical and isotope evidence for secondary phosphate mineralization of grasping spines of Early Palaeozoic chaetognaths Lethaia (IF 1.5) Pub Date : 2020-09-09 Hubert Wierzbowski, Hubert Szaniawski, Błażej Błażejowski
Microscope, cathodoluminescence, chemical and oxygen isotope studies have been conducted to determine the original mineralogy and diagenetic alteration of phosphatic grasping spines of Cambrian chaetognaths. The obtained data, along with a comparison to the composition of conodont apatite, show the presence of a few generations of diagenetic phosphate phases. A thin, outer layer of the spines is composed
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Palaeoecological analysis of a methane seep deposit from the Upper Cretaceous (Maastrichtian) of the U.S. Western Interior Lethaia (IF 1.5) Pub Date : 2020-09-02 Delaney R. Ryan, James D. Witts, Neil H. Landman
Methane seeps were a common feature in the Late Cretaceous Western Interior Seaway of the United States. We document the occurrence of methane seep deposits in the Pierre Shale on the Cedar Creek Anticline in east‐central Montana for the first time. The seep deposits occur in the lowermost part of the Baculites baculus Zone (the Endocostea typica Zone), corresponding to the lowermost Maastrichtian
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Cyclic environmental changes during the Early Toarcian at the Mochras Farm Borehole (Wales): a variable response of the foraminiferal community Lethaia (IF 1.5) Pub Date : 2020-07-12 Francisco J. Rodríguez‐Tovar, Eulogio Pardo‐Igúzquiza, Matias Reolid
Cyclostratigraphical analysis of the foraminiferal assemblages from the Early Toarcian at the Mochras Farm Borehole (Wales) was conducted in order to evaluate the incidence of cyclic palaeoenvironmental changes on the foraminiferal community. Different variables such as type of morphogroup, evolutionary strategy, habitat, particular taxa, diversity and abundance were studied using the Lomb–Scargle