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
Multidisciplinary Sciences
J. -B. Caron, J. Moysiuk
Summary: The article describes the largest Cambrian hurdiid radiodont known so far, Titanokorys gainesi, and highlights information about these ancient populations based on their carapace morphology and co-occurrence, as well as the potential ecological niche competition between them.
ROYAL SOCIETY OPEN SCIENCE
(2021)
Article
Geosciences, Multidisciplinary
Farid Saleh, Romain Vaucher, Jonathan B. Antcliffe, Allison C. Daley, Khadija El Hariri, Khaoula Kouraiss, Bertrand Lefebvre, Emmanuel L. O. Martin, Jean-Philippe Perrillat, Pierre Sansjofre, Muriel Vidal, Bernard Pittet
Summary: The Fezouata Biota in Morocco is a unique Lower Ordovician Lagerstadtte, preserving a diverse biological assemblage with organisms typical of Cambrian Burgess Shale-type ecosystems. Most organisms were already dead and decaying on the seafloor before being buried by occasional storm-induced deposits. The non-preservation of completely cellular organisms like jellyfish in the Fezouata Shale is attributed to pre-burial decay. Despite preservation biases, the autochthonous assemblages offer a unique opportunity to understand Early Palaeozoic seas compared to other Cambrian BST biotas.
EARTH-SCIENCE REVIEWS
(2021)
Article
Biochemistry & Molecular Biology
Joseph Moysiuk, Jean-Bernard Caron
Summary: Radiodonts, including Stanleycaris hirpex, are iconic and bizarre-looking Cambrian animals that provide key insight into the development of the arthropod body plan. This study describes 268 exceptionally preserved specimens of Stanleycaris from the Cambrian Burgess Shale, providing the most complete reconstruction of a radiodont to date. The findings reveal new insights into the segmentation and neuroanatomy of radiodonts, as well as demonstrate a deep evolutionary continuity of certain features. The brain of Stanleycaris supports the hypothesis of an ancestrally bipartite head and brain for arthropods.
Article
Multidisciplinary Sciences
Stephen Pates, Joseph P. Botting, Lucy A. Muir, Joanna M. Wolfe
Summary: Two opabiniid-like euarthropods with anterior proboscises were described from the Middle Ordovician Castle Bank Biota in Wales, UK. Phylogenetic analysis suggests that these specimens may be closely related to radiodonts and deuteropods.
NATURE COMMUNICATIONS
(2022)
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
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
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
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
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
Kelsey M. Jenkins, Derek E. G. Briggs, Javier Luque
Summary: This article describes the details of the eyes of the Cretaceous crab Callichimaera perplexa, which had remarkably large eyes and a unique body form. It is the first post-Paleozoic arthropod known to preserve both internal and external eye structures. The research shows that C. perplexa was a highly visual predator that inhabited well-lit environments.
Article
Paleontology
Paul Johnston, Michael Streng
Summary: The bulk sampling of carbonate units in the middle Cambrian in Utah has yielded abundant silicified stenothecoids, including previously unreported species. These fossils suggest a phylogenetic relationship between Stenothecoida and Brachiopoda, indicating a pan-brachiopod stem group that may have evolved from eccentrothecimorph tommotiids.
ACTA PALAEONTOLOGICA POLONICA
(2021)
Article
Geosciences, Multidisciplinary
Greta M. Ramirez-Guerrero, Christopher B. Cameron
Summary: Pterobranchs originated in the basal Cambrian and are mostly known by their preserved tubes in the fossil record. This study focused on poorly known Middle Cambrian Burgess Shale pterobranchs, providing a complete description of certain species and establishing their phylogenetic relationships within the group.
BULLETIN OF GEOSCIENCES
(2021)
Article
Geology
C. R. Woltz, S. M. Porter, H. Agic, C. M. Dehler, C. K. Junium, L. A. Riedman, M. S. W. Hodgskiss, S. Worndle, G. R. Halverson
Summary: The study compared the presence, preservation quality, and assemblage diversity of organic-walled microfossils in 346 shale samples spanning late Paleoproterozoic to middle Neoproterozoic ages to TOC concentrations. The results suggest that samples containing fossils have significantly lower TOC values and lower preservation quality as TOC increases. It is proposed that high TOC content may decrease preservation quality or inhibit the preservation of organic-walled microfossils.
