Article
Geography, Physical
Russell D. C. Bicknell, James D. Holmes, Stephen Pates, Diego C. Garcia-Bellido, John R. Paterson
Summary: The Cambrian explosion marked the rapid development of complex marine ecosystems on Earth due to predator-prey interactions, which led to the evolution of biomineralised exoskeletons and shell-crushing predators. Injured trilobite specimens from Kangaroo Island, South Australia show evidence of attacks mostly on the posterior thorax, suggesting predators attacked from behind. Larger individuals were more likely to survive attacks and exhibit healed injuries, indicating smaller individuals were likely consumed during an attack.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Paleontology
Harriet B. Drage, James D. Holmes, Diego C. Garcia-Bellido, John R. Paterson
Summary: Trilobites exhibit a wide range of moulting configurations, and there is no true association between moulting behavior and body proportions except for body length. The study highlights the importance of considering museum collection bias in paleontological analyses.
Article
Multidisciplinary Sciences
Nicholas J. Strausfeld, Xianguang Hou, Marcel E. Sayre, Frank Hirth
Summary: The origin and evolution of the arthropod head and brain have long been a mystery, but a recent study of the fossilized nervous system of Cardiodictyon catenulum provides new insights. The study reveals an unsegmented head and brain consisting of three cephalic domains, which align with components of the foregut and head appendages. These findings suggest that the cephalic domains of C. catenulum predate the evolution of the euarthropod head yet correspond to brain regions in modern chelicerates and mandibulates.
Article
Ecology
Jun Zhao, Yujing Li, Paul A. Selden
Summary: This passage describes the diversity and importance of sessile epibenthos in the energy flow process of the Cambrian marine ecosystem. Based on new specimens, two new representatives of the group with characteristics of cnidarians and bryozoans are described. If confirmed, these new findings can contribute to understanding the origin and early evolution of these two phyla. The discovery of more sessile epibenthos suggests a greater diversity in the benthic ecosystem of the Guanshan biota (Cambrian Series 2, Stage 4) than previously believed.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
Article
Geosciences, Multidisciplinary
Russell D. C. Bicknell, James D. Holmes, Diego C. Garcia-Bellido, John R. Paterson
Summary: Malformed specimens of the ellipsocephaloid trilobite Estaingia bilobata from the Emu Bay Shale Konservat-Lagerstatte are reported, with most of the malformed specimens clustering among larger individuals. This suggests that larger forms may have successfully escaped predation attempts or represent individuals with old injuries that have healed through subsequent moulting events. The presence of mangled exoskeletons indicates predation on E. bilobata, highlighting its role in the local ecosystem.
GEOLOGICAL MAGAZINE
(2023)
Article
Multidisciplinary Sciences
Jin-bo Hou, Nigel C. Hughes, Melanie J. Hopkins
Summary: Research suggests that the upper limb branch of Paleozoic biramous arthropods may have had a respiratory function, with morphological similarities to gill structures in crustaceans. This finding may indicate an intermediate stage in the evolution of limb branch fusion.
Article
Paleontology
Yuyan Zhu, Han Zeng, Yao Liu, Fangchen Zhao
Summary: This article describes three new artiopodan species discovered in the lower Cambrian Chengjiang fauna in Yunnan, China. The characteristics and evolutionary affinities of these new species are discussed, and their discovery contributes to the biodiversity of artiopodans from the Cambrian and the Chengjiang fauna.
ACTA PALAEONTOLOGICA POLONICA
(2023)
Article
Multidisciplinary Sciences
Alejandro Izquierdo-Lopez, Jean-Bernard Caron
Summary: This study provides a comprehensive reconstruction of the anatomy, ecology, and evolutionary affinities of Tuzoia, a bivalved arthropod from the Cambrian period. The analysis reveals that Tuzoia swam along the seafloor and used its unique leg structure for predation or scavenging. Bayesian phylogenetic analysis places Tuzoia as an early mandibulate hymenocarine lineage.
ROYAL SOCIETY OPEN SCIENCE
(2022)
Article
Multidisciplinary Sciences
Jie Yang, Tian Lan, Xi-guang Zhang, Martin R. Smith
Summary: The origins of animal phyla and their body plans can be traced back to a burst of evolution during the Cambrian period. However, the fossil remains of the phylum Bryozoa, known as colonial 'moss animals', have been difficult to identify due to their similarities with other animal and algal groups. The phosphatic microfossil Protomelission is currently the strongest candidate for Bryozoa fossils, but new findings suggest that it may actually be the earliest dasycladalean green alga and not a bryozoan.
Article
Paleontology
Elise Wallet, Ben J. Slater, Sebastian Willman, John S. Peel
Summary: The Sirius Passet Lagerstatte in North Greenland is one of the oldest records of soft-bodied metazoan-dominated ecosystems from the early Cambrian. Recent discoveries have expanded the known coverage of organic preservation into shallower water depositional settings, revealing a rich diversity of non-mineralizing metazoans.
PAPERS IN PALAEONTOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Xiao-yu Yang, Jean Vannier, Jie Yang, Deng Wang, Xi-guang Zhang
Summary: Researchers have discovered egg clusters of the tube-dwelling priapulid worm from the Cambrian period, providing insights into the unchanged structure of female tubular gonads over half a billion years. These findings offer key information on the reproductive organs and strategies of early ecdysozoans, shedding light on the significance of ecology in the reproductive strategies and lifestyles of modern and Cambrian worms.
GEOSCIENCE FRONTIERS
(2021)
Article
Geology
Morten Lunde Nielsen, Mirinae Lee, Hong Chin Ng, Jeremy C. Rushton, Katharine R. Hendry, Ji-Hoon Kihm, Arne T. Nielsen, Tae-Yoon S. Park, Jakob Vinther, Philip R. Wilby
Summary: The correct interpretation of soft-bodied fossils relies on a thorough understanding of their taphonomy. This study investigates the mineral replacements in panarthropod fossils from the Sirius Passet Lagerstatte and reveals the potential impacts of deeper burial and metamorphism on fossil preservation. The study provides critical context for interpreting the Sirius Passet biota and identifies late-stage overprints in other biotas.
Article
Multidisciplinary Sciences
Anshuman Swain, Matthew Devereux, William F. Fagan
Summary: This study utilized a high-resolution fossil data set from the Burgess Shale to formulate a measure of preservation bias and successfully predict trophic and competitive interactions through abundance correlation network analyses. The analyses demonstrated a shift in assemblages from specialist interaction-dominated to those dominated by generalist and competitive interactions.
Article
Multidisciplinary Sciences
Hatena Osawa, Jean-Bernard Caron, Robert R. Gaines
Summary: A new well-preserved polychaete species, Ursactis comosa gen. et sp. nov., was discovered in the Burgess Shale. It is the most abundant Cambrian polychaete known to date, with a length ranging from 3 to 15 mm. The number of segments in Ursactis is remarkably small compared to other polychaete species, and the body growth is achieved by increasing the size of existing segments rather than adding new ones.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Geography, Physical
Anna F. Whitaker, James D. Schiffbauer, Derek E. G. Briggs, Wade W. Leibach, Julien Kimmig
Summary: The Spence Shale Lagerstatte is an important fossil deposit, preserving a diverse range of middle Cambrian fossils. The analysis of eldonids specimens from this deposit reveals enrichment in rare earth elements, providing new insights into fossil preservation and diagenetic pathways.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geography, Physical
Russell D. C. Bicknell, James D. Holmes, Stephen Pates, Diego C. Garcia-Bellido, John R. Paterson
Summary: The Cambrian explosion marked the rapid development of complex marine ecosystems on Earth due to predator-prey interactions, which led to the evolution of biomineralised exoskeletons and shell-crushing predators. Injured trilobite specimens from Kangaroo Island, South Australia show evidence of attacks mostly on the posterior thorax, suggesting predators attacked from behind. Larger individuals were more likely to survive attacks and exhibit healed injuries, indicating smaller individuals were likely consumed during an attack.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Biology
Dongjing Fu, David A. Legg, Allison C. Daley, Graham E. Budd, Yu Wu, Xingliang Zhang
Summary: This study reports a new arthropod species, Erratus sperare, with trunk appendages representing an intermediate stage of biramous limb evolution. The species occupies an early node within the basal region of arthropods and reveals the earliest occurrence of the endopod within Deuteropoda.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2022)
Article
Biology
Stephen Pates, Joanna M. Wolfe, Rudy Lerosey-Aubril, Allison C. Daley, Javier Ortega-Hernandez
Summary: In this study, a fossil from the Wheeler Formation of Utah is reinterpreted as a new opabiniid, Utaurora comosa nov. gen. et sp. The phylogenetic evidence expands opabiniids to multiple Cambrian stages, highlighting the power of treespace visualization for resolving imperfectly preserved fossils and expanding the known diversity and spatio-temporal ranges within the euarthropod lower stem group.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2022)
Article
Multidisciplinary Sciences
Farid Saleh, Pauline Guenser, Corentin Gibert, Diego Balseiro, Fernanda Serra, Beatriz G. Waisfeld, Jonathan B. Antcliffe, Allison C. Daley, M. Gabriela Mangano, Luis A. Buatois, Xiaoya Ma, Daniel Vizcaino, Bertrand Lefebvre
Summary: This study investigates the assembly processes of Early Ordovician trilobite and echinoderm communities and finds that dispersal increased over time in trilobite communities but not in echinoderms. Dispersal was likely triggered by factors such as the planktic revolution, fall in seawater temperatures, and changes in oceanic circulation, with control from tectonic frameworks and phylogenetic constraints. The diachronous increase in dispersal within trilobite communities highlights the complexity of ecosystem structuring during the early stages of the Ordovician Radiation.
SCIENTIFIC REPORTS
(2022)
Article
Biodiversity Conservation
Daniel Pauly, James D. Holmes
Summary: This study reexamines a length-frequency sample of the Ordovician trilobite Triarthrus eatoni. The results show that the growth of T. eatoni was asymptotic and slower compared to extant marine isopods.
Article
Paleontology
Julien Kimmig, Stephen Pates, Rhiannon J. LaVine, L. J. Krumenacker, Anna F. Whitaker, Luke C. Strotz, Paul G. Jamison, Val G. Gunther, Glade Gunther, Matt Witte, Allison C. Daley, Bruce S. Lieberman
Summary: The Spence Shale Lagerstatte in northern Utah and southern Idaho is a diverse Burgess Shale-type deposit that contains abundant biomineralized and soft-bodied fossils. Panarthropods dominate the deposit, but the knowledge of soft-bodied panarthropods is limited. This study describes 21 new soft-bodied panarthropods from six locations, providing new insights into the panarthropod fauna of the Spence Shale Lagerstatte and expanding our understanding of their distribution.
JOURNAL OF PALEONTOLOGY
(2023)
Article
Paleontology
Harriet B. Drage, James D. Holmes, Diego C. Garcia-Bellido, John R. Paterson
Summary: Trilobites exhibit a wide range of moulting configurations, and there is no true association between moulting behavior and body proportions except for body length. The study highlights the importance of considering museum collection bias in paleontological analyses.
Review
Geosciences, Multidisciplinary
Gaetan J. -M. Potin, Allison C. Daley
Summary: Radiodonta, a clade of stem lineage arthropods, is one of the most widespread and diverse animal groups during the Cambrian Explosion. They had segmented bodies with laterally-oriented flaps, a distinct radial oral cone, large frontal appendages for feeding, compound eyes, and prominent head carapaces. They provide insights into the paleoecology and evolution of early animal communities and euarthropods.
FRONTIERS IN EARTH SCIENCE
(2023)
Editorial Material
Biology
Ariel D. D. Chipman, Harriet Drage
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2023)
Article
Biology
Russell D. C. Bicknell, Michel Schmidt, Imran A. Rahman, Gregory D. Edgecombe, Susana Gutarra, Allison C. Daley, Roland R. Melzer, Stephen Wroe, John R. Paterson
Summary: The stem-group euarthropod Anomalocaris canadensis is a large Cambrian apex predator. It is debated whether A. canadensis can masticate or manipulate biomineralized prey using its spinose frontal appendages. This study uses an integrative computational approach to analyze an A. canadensis feeding appendage and finds that it is suited for ripping but not for eating hard prey. The findings provide insights into the feeding ecology of A. canadensis and its impact on Cambrian food webs.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2023)
Article
Ecology
Gaetan J. -M. Potin, Pierre Gueriau, Allison C. Daley
Summary: The Fezouata Shale Formation in Morocco is an important source of evidence for the Great Ordovician Biodiversification Event. A study on radiodont frontal appendages from this formation reveals the existence of a new species and the classification of a previously unknown radiodont genus. The Fezouata Shale also shows the highest diversity of suspension-feeding radiodonts in history.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
Article
Ecology
Harriet B. Drage, David A. Legg, Allison C. Daley
Summary: This study describes the moulting behavior and adaptive characteristics of a species of extinct euarthropods called marrellomorphs found in the Early Ordovician Fezouata Shale Lagerstatte of Morocco. The research suggests that these marrellomorphs exhibited similar moulting behaviors to extant lobster-like arthropods, which could be attributed to their complex morphology and the need for extracting complex spines. This study expands our understanding of important characteristics of extinct euarthropods.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
Article
Ecology
Lukas Laibl, Pierre Gueriau, Farid Saleh, Francesc Perez-Peris, Lorenzo Lustri, Harriet B. Drage, Orla G. Bath Enright, Gaetan J. -M. Potin, Allison C. Daley
Summary: Fossils of early developmental stages of Marrellid euarthropods, dating back 480 million years, have been found in the Lower Ordovician Fezouata Shale. These stages exhibit distinct morphology, including unique appendage structures and body composition, suggesting similar methods of locomotion and food processing among different developmental stages. The co-existence of adults and juveniles in the same or nearby sites indicates niche differentiation due to the differences in appendage size and the consumption of food resources. The presence of delicate setae in the posterior trunk appendages of early developmental stages might have served to capture smaller food particles. This simple mode of ontogenetic niche differentiation may have been common in early diverging Euarthropod groups.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
Article
Multidisciplinary Sciences
Farid Saleh, Romain Vaucher, Muriel Vidal, Khadija El Hariri, Lukas Laibl, Allison C. Daley, Juan Carlos Gutierrez-Marco, Yves Candela, David A. T. Harper, Javier Ortega-Hernandez, Xiaoya Ma, Ariba Rida, Daniel Vizcaino, Bertrand Lefebvre
Summary: The Fezouata Biota is a unique Early Ordovician fossil assemblage that revolutionized our understanding of Earth's early animal diversification. The new fossil locality Taichoute extends the temporal distribution of fossil preservation and expands the range of depositional environments. The discovery at this site provides important insights during a key evolutionary transition in the history of life on Earth.
SCIENTIFIC REPORTS
(2022)