A soft-bodied mollusc with radula from the Middle Cambrian Burgess Shale

  title={A soft-bodied mollusc with radula from the Middle Cambrian Burgess Shale},
  author={Jean‐Bernard Caron and Am{\'e}lie H. Scheltema and Christoffer Schander and David M Rudkin},
Odontogriphus omalus was originally described as a problematic non-biomineralized lophophorate organism. Here we re-interpret Odontogriphus based on 189 new specimens including numerous exceptionally well preserved individuals from the Burgess Shale collections of the Royal Ontario Museum. This additional material provides compelling evidence that the feeding apparatus in Odontogriphus is a radula of molluscan architecture comprising two primary bipartite tooth rows attached to a radular… 
Primitive soft-bodied cephalopods from the Cambrian
This work reinterpretes the problematic Middle Cambrian animal Nectocaris pteryx as a primitive (that is, stem-group), non-mineralized cephalopod, based on new material from the Burgess Shale, and indicates that primitive cepinghalopods lacked a mineralized shell, were hyperbenthic, and were presumably carnivorous.
Ontogeny, morphology and taxonomy of the soft‐bodied Cambrian ‘mollusc’ Wiwaxia
It is demonstrated that Wiwaxia did not undergo discrete moult stages; rather, its scleritome developed gradually, with piecewise addition and replacement of individually secreted sclerites.
Mouthparts of the Burgess Shale fossils Odontogriphus and Wiwaxia: implications for the ancestral molluscan radula
  • Martin R. Smith
  • Environmental Science
    Proceedings of the Royal Society B: Biological Sciences
  • 2012
New observations—the shape, distribution and articulation of the individual teeth, and the mouthparts' mode of growth—are incompatible with an annelid interpretation, instead supporting a classification in Mollusca.
An Early Cambrian Radula
Microscopic teeth isolated from the early Cambrian Mahto Formation, Alberta, Canada, are identified as components of a molluscan radula, the oldest on record, and on the assumption that the cuticle and radula derive from the same species, there is a strong case for identifying this fossil as an aculiferan (aplacophoran + polyPLacophora) mollusc, possibly a stem-group chiton.
A spinose stem group brachiopod with pedicle from the Middle Cambrian Burgess Shale
The shells of the new stem group brachiopod are often deformed and do not show signs of brittle breakage, which suggests that the valves were originally either entirely organic in composition or, more likely, had just a minor mineral component.
The original molluscan radula and progenesis in Aplacophora revisited
The arrested development in Aplacophora of a central tooth supports the hypothesis that Aplicophora are progenetic, rather than reflecting the earliest molluscan radula, as a vermiform, shell-less taxon.
Hooking some stem‐group “worms”: fossil lophotrochozoans in the Burgess Shale
  • N. Butterfield
  • Biology, Environmental Science
    BioEssays : news and reviews in molecular, cellular and developmental biology
  • 2006
Analysis of the fossil record of two famously problematic worms, Odontogriphus and Wiwaxia, reveals pronounced anatomical and histological discrepancies with molluscan analogues, such that they are more reliably interpreted as primitive features of the superphylum Lophotrochozoa.
A New Stalked Filter-Feeder from the Middle Cambrian Burgess Shale, British Columbia, Canada
The presence in both animals of a digestive tract with a potential stomach and anus suggest a grade of organization within bilaterians, but relationships with extant phyla are not straightforward.
Pelagiella exigua, an early Cambrian stem gastropod with chaetae: lophotrochozoan heritage and conchiferan novelty
The orientation of Pelagiella and the asymmetry of its gills, comparable to features of several living vetigastropods, nominate it as the earliest fossil mollusc known to exhibit evidence of the developmental torsion characteristic of gastropods.
Orthrozanclus elongata n. sp. and the significance of sclerite-covered taxa for early trochozoan evolution
The scleritome arrangement and constitution in this material corroborates the link between Orthrozanclus and Halkieria, but not with Wiwaxia — and calls into question its purported relationship with molluscs.


Articulated halkieriids from the Lower Cambrian of north Greenland
METAZOAN skeletons appear abruptly in the fossil record near the base of the Cambrian (∼540MyrBP (before present))1,2. In the initial stages of diversification, familiar skeletal remains such as
The Early Cambrian Halkieria is a mollusc
It is found that all the characters that can be observed with certainty are compatible with characters in living molluscs and there is no support for theories that regard Halkieria as belonging to the stem group of either the annelids or brachiopods.
New species of the Cambrian and Ordovician chitons Matthevia and Chelodes from Wisconsin and Queensland; evidence for the early history of polyplacophoran mollusks
Matthevia is the probable ancestor of the widely distributed early Paleozoic chiton Chelodes Davidson & King, 1874 and can be linked to the type species of Chelodes through stratigraphic and morphologic intermediates that occur in Lower Ordovician strata of the United States and Australia.
Articulated Halkieriids from the Lower Cambrian of North Greenland and their Role in Early Protostome Evolution
The hypothesis of halkieriids and their relatives having a key role in annelid-brachiopod-mollusc evolution is in accord with some earlier proposals and recent evidence from molecular biology, but casts doubt on a number of favoured concepts.
Original molluscan radula: Comparisons among Aplacophora, Polyplacophora, Gastropoda, and the Cambrian fossil Wiwaxia corrugata
The original molluscan radula was similar to the radula found in Helicoradomena species, and it is shown that distichy also occurs during early development in several species of gastropods and polyplacophorans.
Ediacara-type fossils in Cambrian sediments
Fossil assemblages that preserve soft-bodied organisms are essential for our understanding of the composition and diversity of past life. The worldwide terminal Proterozoic Ediacara-type fossils
An Odontogriphid from the Upper Permian of Australia
A problematic organism, Bowengriphus perphlegis gen. et sp. nov., is described based on two specimens from the Late Permian Rangal Coal Measures of eastern central Queensland. It displays a
Articulated Palaeozoic fossil with 17 plates greatly expands disparity of early chitons
The highly conserved body plan of living chitons belies the broad disparity of this clade during the Palaeozoic era.
A reassessment of the enigmatic Burgess Shale fossil Wiwaxia corrugata (Matthew) and its relationship to the polychaete Canadia spinosa Walcott
Anatomical and histological comparison with modern organisms indicates that Wiwaxia sclerites are polychaete paleae (flattened setae) and that WiWaxia was a jawed annelid broadly related to the extantpolychaete families Chrysopetalidae and/or Aprhoditidae (Palmyra).