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How does rapid burial work? New insights from experiments with echinoderms Palaeontology (IF 2.6) Pub Date : 2024-04-17 Malton Carvalho Fraga, Cristina Silveira Vega
This research explores the significance of rapid burial in preserving fossils, with a particular focus on free‐living echinoderms. Experiments were based on ophiuroids to simulate burial under different turbiditic flows. The results showed that a bed thickness of around 10 cm is a limit for the preservation of whole skeletons in most cases. The type of sediment can affect the integrity of the buried
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Response of Mediterranean Sea bivalves to Pliocene–Pleistocene environmental changes Palaeontology (IF 2.6) Pub Date : 2024-03-19 Alessandro Mondanaro, Stefano Dominici, Silvia Danise
The Mediterranean Sea is recognized as a hotspot of marine biodiversity. Analysing its past biodiversity can help in understanding species' response to climate change. We built a species‐level dataset of bivalve occurrences across the Zanclean–Calabrian interval, a time characterized by significant changes in climate, and by bivalve extinctions. The dataset includes more than 400 species distributed
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Modelling height–diameter relationships in living Araucaria (Araucariaceae) trees to reconstruct ancient araucarian conifer height Palaeontology (IF 2.6) Pub Date : 2024-03-12 Aowei Xie, Carole T. Gee, Eva M. Griebeler
To reconstruct a fossil forest in three dimensions, an accurate estimation of tree height is crucial. However, modelling the height–diameter relationship of ancient trees is difficult, because the trunks of fossil trees are usually fragmentary, making direct height measurements impossible. One practical approach for reconstructing ancient tree height is to use growth models based on the height–diameter
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High‐precision body mass predictors for small mammals: a case study in the Mesozoic Palaeontology (IF 2.6) Pub Date : 2024-03-05 E.J. Huang, Jacob D. Wilson, Bhart‐Anjan S. Bhullar, Gabriel S. Bever
Body mass is a pivotal quantity in palaeobiology but must be inferred from an imperfect fossil record. We analyse the performance of regression models derived from various dentoskeletal predictors in mammals to inform fossils from the early, Mesozoic history of this radiation. Our focus is on the critical small end of the size spectrum; critical because the earliest mammals were small, because small
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Correction to ‘Ecological novelty at the start of the Cambrian and Ordovician radiations of echinoderms’ Palaeontology (IF 2.6) Pub Date : 2024-02-23
Novack-Gottshall, P. M., Purcell, J., Sultan, A., Ranjha, I., Deline, B. and Sumrall, C. D. 2024. Palaeontology, 67, e12688. Figure 6 should illustrate echinoderm phyloecospace through the Cambrian and Ordovician periods using the time-scaled UEH phylogeny number 49 as an example, but instead shows the alternative representation using the EAT topology (and phylogeny no. 57; see Fig. S6). This is the
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Forged soft tissues revealed in the oldest fossil reptile from the early Permian of the Alps Palaeontology (IF 2.6) Pub Date : 2024-02-15 Valentina Rossi, Massimo Bernardi, Mariagabriella Fornasiero, Fabrizio Nestola, Richard Unitt, Stefano Castelli, Evelyn Kustatscher
Tridentinosaurus antiquus represents one of the oldest fossil reptiles and one of the very few skeletal specimens with evidence of soft tissue preservation from the Cisuralian (Early Permian) of the Italian Alps. The preservation and appearance of the fossil have puzzled palaeontologists for decades and its taphonomy and phylogenetic position have remained unresolved. We reanalysed T. antiquus using
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Ecological novelty at the start of the Cambrian and Ordovician radiations of echinoderms Palaeontology (IF 2.6) Pub Date : 2024-01-22 Philip M. Novack-Gottshall, Jack Purcell, Ali Sultan, Isa Ranjha, Bradley Deline, Colin D. Sumrall
The Cambrian and Ordovician radiations marked the origins of all major echinoderm clades and established their Phanerozoic ecological blueprint. Recent claims of modest innovation of early echinoderms and other animals suggest constraints on novelty during the origins of phyla. Here, we document the life-habit richness, body size, tiering, habitat usage, mobility, diet and foraging habits of 366 Cambrian–Ordovician
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Germ-soma differentiation and reproduction in a new species of early Cambrian acritarch Palaeontology (IF 2.6) Pub Date : 2023-12-26 Wei Liu, Zongjun Yin, Bing Pan, Bing Shen, Lin Dong, Guoxiang Li
As a significant evolutionary innovation, multicellularity has independently evolved multiple times throughout the evolutionary history of eukaryotes, making a substantial contribution to their diversity. In retracing the multicellularity of eukaryotes, deep-time fossil records play an irreplaceable role. In this paper, we report a new acritarch Concavaesphaera ornata gen. et sp. nov. from the early
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Quantitative ichnology: a novel framework to determine the producers of locomotory trace fossils with the ichnogenus Gordia as a case study Palaeontology (IF 2.6) Pub Date : 2023-12-20 Zekun Wang, Imran A. Rahman
Trace fossils record the interactions between organisms and their surroundings, and can therefore provide unique insights into the coevolution of trace makers and the environment. However, identifying the producers of trace fossils is challenging because different animals can create very similar traces and many ichnotaxa can therefore only be attributed to broad morphological grades. For example, simple
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Macroscopic fossils from the Chuanlinggou Formation of North China: evidence for an earlier origin of multicellular algae in the late Palaeoproterozoic Palaeontology (IF 2.6) Pub Date : 2023-12-19 Jingqi Liu, Yang Zhang, Xiaoying Shi, Anfeng Chen, Dongjie Tang, Tinglu Yang
Multicellular algae are the core topic for understanding the early life evolution on Earth. The timing of origin and cellular differentiation of multicellular algae, however, remains poorly constrained. The Palaeoproterozoic to early Mesoproterozoic is a critical period during which multicellular algae began to occur and evolve in marine environments. This paper reports well-preserved multicellular
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Machine-learning-based morphological analyses of leaf epidermal cells in modern and fossil ginkgo and their implications for palaeoclimate studies Palaeontology (IF 2.6) Pub Date : 2023-12-17 Li Zhang, Yongdong Wang, Micha Ruhl, Yuanyuan Xu, Yanbin Zhu, Pengcheng An, Hongyu Chen, Defei Yan
Leaf stomata form an essential conduit between plant tissue and the atmosphere, thus presenting a link between plants and their environments. Changes in their properties in fossil leaves have been studied widely to infer palaeo-atmospheric-CO2 in deep time, ranging from the Palaeozoic to the Cenozoic. Epidermal cells of leaves, however, have often been neglected for their usefulness in reconstructing
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Developmental models shed light on the earliest dental tissues, using Astraspis as an example Palaeontology (IF 2.6) Pub Date : 2023-12-11 Guillaume Houée, Jérémie Bardin, Damien Germain, Philippe Janvier, Nicolas Goudemand
Fossils of extinct jawless vertebrates are pivotal to deciphering the evolutionary paths that led to the various forms of the vertebrate skeleton. For example, Pteraspidomorphs (stem-gnathostomes), such as the Ordovician Astraspis, display some of the oldest remains of bony and ‘dental’ (dentine and enameloid) tissues. However, the identification of the very nature of these early mineralized tissues
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Uncovering a phylogenetic signal in plant biopolymer chemistry: a comparison of sporopollenin isolation approaches for use in palynological research Palaeontology (IF 2.6) Pub Date : 2023-12-05 Phillip E. Jardine, Matthew S. Kent, Wesley T. Fraser, Klaus-Holger Knorr, Barry H. Lomax
Sporomorphs (pollen and spores) are a mainstay of research into past vegetation, and increasingly sporomorph chemistry is being used as a palaeoecological tool. To make extant sporomorphs directly comparable to fossil specimens, fresh material is processed to remove labile compounds and isolate the sporopollenin wall. A range of processing approaches are currently in use, but the chemistries produced
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Dental microwear texture analysis reveals a likely dietary shift within Late Cretaceous ornithopod dinosaurs Palaeontology (IF 2.6) Pub Date : 2023-12-01 Tai Kubo, Mugino O. Kubo, Manabu Sakamoto, Daniela E. Winkler, Masateru Shibata, Wenjie Zheng, Xingsheng Jin, Hai-Lu You
Dinosaurs were the dominant megaherbivores during the Cretaceous when angiosperms, the flowering plants, emerged and diversified. How herbivorous dinosaurs responded to the increasing diversity of angiosperms is largely unknown due to the lack of methods that can reconstruct diet directly from body fossils. We applied dental microwear texture analysis (DMTA), an approach that quantifies microtopography
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Inaccurate fossil placement does not compromise tip-dated divergence times Palaeontology (IF 2.6) Pub Date : 2023-11-22 Nicolás Mongiardino Koch, Russell J. Garwood, Luke A. Parry
Time-scaled phylogenies underpin the interrogation of evolutionary processes across deep timescales, as well as attempts to link these to Earth's history. By inferring the placement of fossils and using their ages as temporal constraints, tip dating under the fossilized birth–death (FBD) process provides a coherent prior on divergence times. At the same time, it also links topological and temporal
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Putting the F into FBD analysis: tree constraints or morphological data? Palaeontology (IF 2.6) Pub Date : 2023-11-12 Joëlle Barido-Sottani, Alexander Pohle, Kenneth De Baets, Duncan Murdock, Rachel C. M. Warnock
The fossilized birth–death (FBD) process provides an ideal model for inferring phylogenies from both extant and fossil taxa. Using this approach, fossils are directly integrated into the tree, leading to a statistically coherent prior on divergence times. Since fossils are typically not associated with molecular sequences, additional information is required to place fossils in the tree. We use simulations
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Limited convergence in the postcranium of aquatic Crocodylomorpha Palaeontology (IF 2.6) Pub Date : 2023-11-12 Isaure Scavezzoni, Valentin Fischer
Thalattosuchia (Early Jurassic to Early Cretaceous) and Dyrosauridea (Late Cretaceous to Early Eocene) are crocodylomorph archosaurs which diversified in fluvial and marine environments and endured extinction events (i.e. Jurassic–Cretaceous boundary for Thalattosuchia; Cretaceous–Palaeogene for Dyrosauridea). Their postcrania remain globally undervalued in anatomical descriptions and diagnoses, shrouding
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Bridging the extant and fossil record of planktonic foraminifera: implications for the Globigerina lineage Palaeontology (IF 2.6) Pub Date : 2023-11-08 Alessio Fabbrini, Mattia Greco, Francesco Iacoviello, Michal Kucera, Thomas H.G. Ezard, Bridget S. Wade
We conducted a morphometric study and wall texture analysis on extant and fossil specimens of the planktonic foraminifera Globigerina falconensis plexus. Our global data reveal morphological inconsistencies between fossil and extant populations. Our results are significant as G. falconensis is widely used in palaeoceanographic studies in conjunction with its sister taxon G. bulloides. Morphologically
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The dentary of hadrosauroid dinosaurs: evolution through heterochrony Palaeontology (IF 2.6) Pub Date : 2023-10-26 D. Fredrik K. Söderblom, Alejandro Blanco, Albert Prieto-Márquez, Nicolás E. Campione
The near-global distribution of hadrosaurid dinosaurs during the Cretaceous has been attributed to mastication, a behaviour commonly recognized as a mammalian adaptation. Its occurrence in a non-mammalian lineage should be accompanied by the evolution of several morphological modifications associated with food acquisition and processing. This study investigated morphological variation in the dentary
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Quantifying the gastral mass in Early Cretaceous ornithuromorphs (Aves, Ornithothoraces) from the Jehol avifauna Palaeontology (IF 2.6) Pub Date : 2023-10-18 Shumin Liu, Zhiheng Li, Di Liu, Jingmai K. O'Connor
Some birds intentionally ingest stones to facilitate digestion of hard foodstuffs, a behaviour inherited from non-avian dinosaurs and present in some of the earliest birds, as evidenced by clusters of gastroliths preserved within the abdominal cavity of a wide range of dinosaurs and Cretaceous birds. For the first time, high-resolution computed laminographic and computed tomographic scans were used
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Taxic and morphological diversification during the early radiation of Clupeomorpha (Actinopterygii, Teleostei) Palaeontology (IF 2.6) Pub Date : 2023-10-13 Edna Rodríguez-Sánchez, Jesús Alvarado-Ortega, Bruno A. Than-Marchese
Evolutionary radiation is a problematic concept whose definition and classification have recently changed. Radiations can be defined as the pattern of abrupt increase in diversity of a lineage. It is relevant to evaluate the presence and interaction of different types of radiation in extant and fossil organisms to adequately delimitate the radiation types and to know the diversity in the context of
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Cover Image Palaeontology (IF 2.6) Pub Date : 2023-09-03
Cover illustration: Cloudina from the upper Ediacaran of Lijiagou in Shaanxi Province, China (image courtesy of Prof. Shuhai Xiao). Specimen height approx. 2–3 mm.
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Rise and fall of the phacopids: the morphological history of a successful trilobite family Palaeontology (IF 2.6) Pub Date : 2023-09-03 Valentin Bault, Catherine Crônier, Claude Monnet, Diego Balseiro, Fernanda Serra, Beatriz Waisfeld, Arnaud Bignon, Juan José Rustán
Phacopidae were a successful family of the Silurian–Devonian period. Although their diversity trends are well identified, their shape evolution is unknown; their morphology often considered to be conservative. We have quantified these morphologies using geometric morphometrics (landmarks) and investigated their evolution using morphological disparity indices. Results identified morphological variations
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A new method for extracting conodonts and radiolarians from chert with NaOH solution Palaeontology (IF 2.6) Pub Date : 2023-08-14 Manuel Rigo, Tetsuji Onoue, Qiangwang Wu, Yuki Tomimatsu, Lisa Santello, Yixing Du, Xin Jin, Angela Bertinelli
Microfossils are important components of sedimentary rocks used for palaeontological, biostratigraphic, palaeoenvironmental and palaeoclimatic investigations. They are usually extracted from rocks using an acid solution, which might vary depending on the embedding rock lithology. Here we propose a new method using common NaOH (sodium hydroxide; soda) to digest cherts (micro- and cryptocrystalline quartz)
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Palaeobiology and taphonomy of the rangeomorph Culmofrons plumosa Palaeontology (IF 2.6) Pub Date : 2023-07-31 Giovanni Pasinetti, Duncan McIlroy
The deep marine Ediacaran fossil record of Avalonia is dominated by the Rangeomorpha, a clade characterized by up to four orders of fractal-like branching. Despite their abundance, morphological diversity and the recent increase in Ediacaran studies, aspects of their palaeobiology, palaeoecology and phylogenetic position in the tree of life are still hotly debated. The clade has traditionally been
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What's inside a sauropod limb? First three-dimensional investigation of the limb long bone microanatomy of a sauropod dinosaur, Nigersaurus taqueti (Neosauropoda, Rebbachisauridae), and implications for the weight-bearing function Palaeontology (IF 2.6) Pub Date : 2023-07-31 Rémi Lefebvre, Ronan Allain, Alexandra Houssaye
Various terrestrial tetrapods convergently evolved to gigantism (large body sizes and masses), the most extreme case being sauropod dinosaurs. Heavy weight-bearing taxa often show external morphological features related to this condition, but also adequacy in their limb bone inner structure: a spongiosa filling the medullary area and a rather thick cortex varying greatly in thickness along the shaft
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Preservational modes of some ichthyosaur soft tissues (Reptilia, Ichthyopterygia) from the Jurassic Posidonia Shale of Germany Palaeontology (IF 2.6) Pub Date : 2023-07-27 Randolph G. De La Garza, Peter Sjövall, Rolf Hauff, Johan Lindgren
Konservat-Lagerstätten, such as the Toarcian (Early Jurassic) Posidonia Shale of southwestern Germany, are renowned for their spectacular fossils. Ichthyosaur skeletons recovered from this formation are frequently associated with soft tissues; however, the preserved material ranges from three-dimensional, predominantly phosphatized structures to dark films of mainly organic matter. We examined soft-tissue
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The evolutionary origin of the durophagous pelagic stingray ecomorph Palaeontology (IF 2.6) Pub Date : 2023-07-26 Giuseppe Marramà, Eduardo Villalobos-Segura, Roberto Zorzin, Jürgen Kriwet, Giorgio Carnevale
Studies of the origin of evolutionary novelties (novel traits, feeding modes, behaviours, ecological niches, etc.) have considered a number of taxa experimenting with new body plans, allowing them to occupy new habitats and exploit new trophic resources. In the marine realm, colonization of pelagic environments by marine fishes occurred recurrently through time. Stingrays (Myliobatiformes) are a diverse
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Cover Image Palaeontology (IF 2.6) Pub Date : 2023-07-11
Cover illustration: Cloudina from the upper Ediacaran of Lijiagou in Shaanxi Province, China (image courtesy of Prof. Shuhai Xiao). Specimen height approx. 2–3 mm.
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Exceptions to the temperature–size rule: no Lilliput Effect in end-Permian ostracods (Crustacea) from Aras Valley (northwest Iran) Palaeontology (IF 2.6) Pub Date : 2023-07-11 Paulina S. Nätscher, Jana Gliwa, Kenneth De Baets, Abbas Ghaderi, Dieter Korn
The body size of marine ectotherms is often negatively correlated with ambient water temperature, as seen in many clades during the hyperthermal crisis of the end-Permian mass extinction (c. 252 Ma). However, in the case of ostracods, size changes during ancient hyperthermal events are rarely quantified. In this study, we evaluate the body size changes of ostracods in the Aras Valley section (northwest
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Decoding the drivers of deep-time wetland biodiversity: insights from an early Permian tropical lake ecosystem Palaeontology (IF 2.6) Pub Date : 2023-06-16 Steffen Trümper, Björn Vogel, Sebastian Germann, Ralf Werneburg, Joerg W. Schneider, Alexandra Hellwig, Ulf Linnemann, Mandy Hofmann, Ronny Rößler
Wetlands are important to continental evolution, providing both arenas and refugia for emerging and declining biotas. This significance and the high preservation potential make the resulting fossiliferous deposits essential for our understanding of past and future biodiversity. We reconstruct the trophic structure and age of the early Permian Manebach Lake ecosystem, Germany, a thriving wetland at
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Early Cenozoic increases in mammal diversity cannot be explained solely by expansion into larger body sizes Palaeontology (IF 2.6) Pub Date : 2023-06-16 Gemma Louise Benevento, Roger B. J. Benson, Roger A. Close, Richard J. Butler
A prominent hypothesis in the diversification of placental mammals after the Cretaceous–Palaeogene (K/Pg) boundary suggests that the extinction of non-avian dinosaurs resulted in the ecological release of mammals, which were previously constrained to small body sizes and limited species richness. This ‘dinosaur incumbency hypothesis’ may therefore explain increases in mammalian diversity via expansion
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Unique dentition of rhynchosaurs and their two-phase success as herbivores in the Triassic Palaeontology (IF 2.6) Pub Date : 2023-06-08 Thitiwoot Sethapanichsakul, Robert A. Coram, Michael J. Benton
Rhynchosaurs were key herbivores over much of the world in the Middle and Late Triassic, often dominating their faunas ecologically, and much of their success may relate to their dentition. They show the unique ankylothecodont mode of tooth implantation, with deep roots embedded in the bone of the jaw and low crowns that were rapidly worn down in use. During growth, the main area of oral food processing
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Cranial endocast of Anagale gobiensis (Anagalidae) and its implications for early brain evolution in Euarchontoglires Palaeontology (IF 2.6) Pub Date : 2023-06-01 Sergi López-Torres, Ornella C. Bertrand, Madlen M. Lang, Łucja Fostowicz-Frelik, Mary T. Silcox, Jin Meng
Anagalids are an extinct group of primitive mammals from the Asian Palaeogene thought to be possible basal members of Glires. Anagalid material is rare, with only a handful of crania known. Here we describe the first virtual endocast of an anagalid, based on the holotype of Anagale gobiensis (AMNH 26079; late Eocene, China), which allows for comparison with published endocasts from fossil members of
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Associations between trilobite intraspecific moulting variability and body proportions: Estaingia bilobata from the Cambrian Emu Bay Shale, Australia Palaeontology (IF 2.6) Pub Date : 2023-05-08 Harriet B. Drage, James D. Holmes, Diego C. García-Bellido, John R. Paterson
Trilobites were notably flexible in the moulting behaviours they employed, producing a variety of moult configurations preserved in the fossil record. Investigations seeking to explain this moulting variability and its potential impacts are few, despite abundant material being available for study. We present the first quantitative study on moulting in a single trilobite species using a dataset of almost
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Potential of closed contour analysis for species differentiation and holotype designation: a case study on lower Norian (Upper Triassic) conodonts Palaeontology (IF 2.6) Pub Date : 2023-04-20 Attila Virág, Viktor Karádi
Geometric morphometric approaches become increasingly applied in the fields of biology and palaeontology. Taxonomy is a good example, where a long-standing intention of scientists is to eliminate subjectivity as much as possible. In the case of biostratigraphically important conodont elements, the application of such methods is not widespread. Only a handful of studies attempted to deal with the morphological
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Three-dimensional anatomy of the Tully monster casts doubt on its presumed vertebrate affinities Palaeontology (IF 2.6) Pub Date : 2023-04-16 Tomoyuki Mikami, Takafumi Ikeda, Yusuke Muramiya, Tatsuya Hirasawa, Wataru Iwasaki
Tullimonstrum gregarium, also known as the Tully monster, is a well-known phylogenetic enigma, fossils of which have been found only in the Mazon Creek Lagerstätte. The affinities of Tullimonstrum have been debated since its discovery in 1966, because its peculiar morphology with stalked eyes and a proboscis cannot easily be compared with any known animal morphotypes. Recently, the possibility that
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The locomotor ecomorphology of Mesozoic marine reptiles Palaeontology (IF 2.6) Pub Date : 2023-04-17 Susana Gutarra, Thomas L. Stubbs, Benjamin C. Moon, Beatrice H. Heighton, Michael J. Benton
The aftermath of the end-Permian mass extinction provided ecological opportunities for many groups of reptiles, marking the beginning of reptile dominance of the Mesozoic oceans. Clades such as ichthyosaurs, thalattosuchians, sauropterygians, mosasaurs and turtles evolved a remarkable diversity of ecological niches and became important components of aquatic ecosystems. Locomotion is a key aspect of
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Vital statistics, absolute abundance and preservation rate of Tyrannosaurus rex Palaeontology (IF 2.6) Pub Date : 2023-04-18 Eva M. Griebeler
I present a simulation model on vital statistics, absolute abundance (N, total number of individuals that ever lived) and preservation rate (p, minimum number of fossils known divided by N) of Tyrannosaurus rex. It is based on a published age-structured population model that assumes a reptile or bird-like reproduction for T. rex to estimate its age-specific survival rates. My model applies input variables
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Lasanius, an exceptionally preserved Silurian jawless fish from Scotland Palaeontology (IF 2.6) Pub Date : 2023-04-10 Jane C. Reeves, Roy A. Wogelius, Joseph N. Keating, Robert S. Sansom
The fossil record of non-biomineralizing, soft-bodied taxa is our only direct evidence of the early history of vertebrates. A robust reconstruction of the affinities of these taxa is critical to unlocking vertebrate origins and understanding the evolution of skeletal tissues, but these taxa invariably have unstable and poorly supported phylogenetic positions. At the cusp between mineralized bony vertebrates
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Contrasting patterns of disparity suggest differing constraints on the evolution of trilobite cephalic structures during the Cambrian ‘explosion’ Palaeontology (IF 2.6) Pub Date : 2023-04-10 James D. Holmes
Trilobites are an abundant group of Palaeozoic marine euarthropods that appear abruptly in the fossil record c. 521 million years ago. Quantifying the development of morphological variation (or ‘disparity’) through time in fossil groups like trilobites is critical in understanding evolutionary radiations such as the Cambrian ‘explosion’. Here, I use geometric morphometrics to quantify ‘cumulative disparity’
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The effect of geological biases on our perception of early land plant radiation Palaeontology (IF 2.6) Pub Date : 2023-03-20 Eliott Capel, Claude Monnet, Christopher J. Cleal, Jinzhuang Xue, Thomas Servais, Borja Cascales-Miñana
The Silurian–Devonian plant radiation was a critical development in the evolution of early terrestrial ecosystems. Characterizing the diversity dynamics of this radiation has been a focus of numerous studies. However, little is known about the impact of geological bias on our perception of this biodiversification. Here, we use a new, comprehensive compilation of plant occurrences from North America
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Did the Late Ordovician mass extinction event trigger the earliest evolution of ‘strophodontoid’ brachiopods? Palaeontology (IF 2.6) Pub Date : 2023-03-20 Bing Huang, Di Chen, David A.T. Harper, Jiayu Rong
‘Strophodontoid’ brachiopods represented the majority of strophomenide brachiopods in the Silurian and Devonian periods. They are characterized by denticles developed along the hinge line. The evolution of denticles correlated with the disappearance of dental plates and teeth and were already present when the clade originated in the Late Ordovician. Specimens of Eostropheodonta parvicostellata from
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Phylogenetic structure of the extinction and biotic factors explaining differential survival of terrestrial notosuchians at the Cretaceous–Palaeogene crisis Palaeontology (IF 2.6) Pub Date : 2023-02-20 Paul Aubier, Stéphane Jouve, Johann Schnyder, Jorge Cubo
Although the clade Crocodylomorpha is represented by few extant species (Crocodylia), it has a rich fossil record. Hundreds of species, adapted to terrestrial, semi-aquatic and marine environments, have existed over more than 200 million years. Numerous studies have attempted to characterize the factors driving the diversification and extinction events of Crocodylomorpha, resulting in ambiguous and
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Morphological disparity and evolutionary rates of cranial and postcranial characters in sloths (Mammalia, Pilosa, Folivora) Palaeontology (IF 2.6) Pub Date : 2023-02-21 Daniel M. Casali, Alberto Boscaini, Timothy J. Gaudin, Fernando A. Perini
Sloth morphological evolution has been widely studied qualitatively, with comparative anatomy and morpho-functional approaches, or through quantitative assessments of morphological variation using morphometrics. Only recently, however, have folivoran morphological disparity and evolutionary rates begun to be evaluated using discrete character data. Nonetheless, patterns of morphological evolution in
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An early Cambrian polyp reveals a potential anemone-like ancestor for medusozoan cnidarians Palaeontology (IF 2.6) Pub Date : 2023-02-09 Yang Zhao, Luke A. Parry, Jakob Vinther, Frances S. Dunn, Yu-Jing Li, Fan Wei, Xian-Guang Hou, Pei-Yun Cong
Cnidarians form a disparate phylum of animals and their diploblastic body plan represents a key step in animal evolution. Cnidarians are split into two main classes; anthozoans (sea anemones, corals) are benthic polyps, while medusozoans (hydroids, jellyfishes) generally have alternating life cycle stages of polyps and medusae. A sessile polyp is present in both groups and is widely regarded as the
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Thecate stem medusozoans (Cnidaria) from the early Cambrian Chengjiang biota Palaeontology (IF 2.6) Pub Date : 2023-02-02 Hanzhi Qu, Kexin Li, Qiang Ou
Cnidarians are phylogenetically located near the base of the ‘tree of animals’, and their early evolution had a profound impact on the rise of bilaterians. However, the early diversity and phylogeny of this ‘lowly’ metazoan clade has hitherto been enigmatic. Fortunately, cnidarian fossils from the early Cambrian could provide key insights into their evolutionary history. Here, based on a scrutiny of
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Species of Dickinsonia Sprigg from the Ediacaran of South Australia Palaeontology (IF 2.6) Pub Date : 2023-02-07 Scott D. Evans, Gene Hunt, James G. Gehling, Erik A. Sperling, Mary L. Droser
An iconic member of the Ediacara Biota, Dickinsonia Sprigg is one of few such taxa with multiple species. Here we use Gaussian finite mixture models to assess the validity of species distinctions for this genus. Our results indicate that the five described species of Dickinsonia from the Ediacara Member, South Australia are better classified as two based on multiple approaches. Two different methods
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Testing the success of palaeontological methods in the delimitation of clam shrimp (Crustacea, Branchiopoda) on extant species Palaeontology (IF 2.6) Pub Date : 2023-01-16 Manja Hethke, Kai Hartmann, Matthias Alberti, Theresa Kutzner, Martin Schwentner
Fossil spinicaudatan taxonomy heavily relies on carapace features (size, shape, ornamentation) and palaeontologists have greatly refined methods to study and describe carapace variability. Whether carapace features alone are sufficient for distinguishing between species of a single genus has remained untested. In our study, we tested common palaeontological methods on 481 individuals of the extant
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The utility of probability plotting in palaeobiology Palaeontology (IF 2.6) Pub Date : 2022-12-27 Larry F. Rinehart, Andrew B. Heckert, Spencer G. Lucas
We introduce probability plotting for general use in the analysis of biological and palaeontological morphometric data. When applied to morphometric data, this analytical tool can yield palaeoecological, ontogenetic and demographic information. We have adapted and expanded a statistical tool used in reliability engineering, mechanical or electrical lifetime analysis, geochemistry and ore mineral analysis
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How long does a brachiopod shell last on a seafloor? Modern mid-bathyal environments as taphonomic analogues of continental shelves prior to the Mesozoic Marine Revolution Palaeontology (IF 2.6) Pub Date : 2022-12-15 Adam Tomašových, Diego A. García-Ramos, Rafał Nawrot, James H. Nebelsick, Martin Zuschin
Carbonate skeletal remains are altered and disintegrate at yearly to decadal scales in present-day shallow-marine environments with intense bioerosion and dissolution. Present-day brachiopod death assemblages are invariably characterized by poor preservation on continental shelves, and abundant articulated shells of brachiopods with complete brachidia are thus not expected to be preserved if not rapidly
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First application of dental microwear texture analysis to infer theropod feeding ecology Palaeontology (IF 2.6) Pub Date : 2022-12-09 Daniela E. Winkler, Tai Kubo, Mugino O. Kubo, Thomas M. Kaiser, Thomas Tütken
Theropods were the dominating apex predators in most Jurassic and Cretaceous terrestrial ecosystems. Their feeding ecology has always been of great interest, and new computational methods have yielded more detailed reconstructions of differences in theropod feeding behaviour. Many approaches, however, rely on well-preserved skulls. Dental microwear texture (DMT) analysis is potentially applicable to
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Metamorphism as the cause of bone alteration in the Jarrow assemblage (Langsettian, Pennsylvanian) of Ireland Palaeontology (IF 2.6) Pub Date : 2022-12-07 Aodhán Ó Gogáin, Gary O'Sullivan, Thomas Clements, Brendan C. Hoare, John Murray, Patrick N. Wyse Jackson
The Jarrow assemblage is a Lagerstätte of Pennsylvanian tetrapods and fish preserved in the Leinster Coalfield, Ireland. Fossils from this site have an interesting taphonomy that is not observed in other Pennsylvanian coal swamp assemblages. Jarrow tetrapod bone material has undergone alteration and eventual coalification, causing specimens to become poorly defined from the surrounding coal matrix