Distinguishing anomalocaridids from arthropods and priapulids

  title={Distinguishing anomalocaridids from arthropods and priapulids},
  author={Hou Xian-guang and Jan Robert Bergstr{\"o}m and Yang Jie},
  journal={Geological Journal},
The Chengjiang fossil lagerstätte has yielded four described species of dinocaridids. These have been interpreted either as arthropods or as arthropod progenitors, occasionally with the anomalocaridid Parapeytoia yunnanensis serving as a link. This view is rejected both because anomalocaridids have a number of derived characters absent from early arthropods, and also because a shared origin gives a more parsimonious picture. Sclerites thought to belong to the mouth of P. yunnanensis differ… 

The oral cone of Anomalocaris is not a classic ‘‘peytoia’’

It is shown that Anomalocaris has a different oral cone, with only three large plates and a variable number of smaller and medium plates, which suggests that suction, rather than biting, was used for food ingestion, and that anomalies in general employed a range of different scavenging and predatory feeding strategies.

A giant Ordovician anomalocaridid

Phylogenetic analyses support a position of anomalocaridids in the arthropod stem, as a sister group to the euarthropods, and confirm the presence of a dorsal array of flexible blades attached to a transverse rachis on the trunk segments.

The Burgess Shale Anomalocaridid Hurdia and Its Significance for Early Euarthropod Evolution

Hurdia possesses a general body architecture similar to those of Anomalocaris and Laggania, but differs from those anomalocaridids by possessing a prominent anterior carapace structure, and provides insight into the origins of important arthropod features, such as the head shield and respiratory exites.

New anomalocaridid appendages from the Burgess Shale, Canada

Abstract:  The complex history of description of the anomalocaridids has partly been caused by the fragmentary nature of these fossils. Frontal appendages and mouth parts are more readily preserved

A Possible Larval Roundworm from the Cambrian 'Orsten' and Its Bearing on the Phylogeny of Cycloneuralia

Shergoldana australiensis is presented here as possibly the first record of a free-living immature cycloneuralian from the Cambrian, even if it remains uncertain whether it has closer affinities to the one or other in-group.

Morphology of diverse radiodontan head sclerites from the early Cambrian Chengjiang Lagerstätte, south-west China

Six morphotypes of possible hurdiid head sclerite elements from the Chengjiang Lagerstätte are described, some of which are closely associated with other typical radiodontan body parts and reflect a fundamental structure of double layers of cuticle.

The xenusian-to-anomalocaridid transition within the lobopodians

A scenario of almost complete transition from early lobopodians to ancestral arthropods within the xenusian-anomalocaridid segment of the phylogenetic tree is results in.

Loricate larvae (Scalidophora) from the Middle Cambrian of Australia

A new species of Cambrian Scalidophora, Orstenoloricus shergoldii gen. et sp.

Functional morphology, ontogeny and evolution of mantis shrimp‐like predators in the Cambrian

The arrangement of the elbow joint supports the view that the great appendage evolved into the chelicera of Chelicerata sensu stricto, as similar joints are found in various ingroup taxa such as Xiphosura, Opiliones or Palpigradi.



Evidence for Monophyly and Arthropod Affinity of Cambrian Giant Predators

Evidence indicates that anomalocaridids, Opabinia, and Kerygmachela form a monophyletic clade, and for this group an unnamed (sub)phylum-level taxon within an arthropod (super)Phylum is proposed.

New rare bivalved arthropods from the Lower Cambrian Chengjiang fauna, Yunnan, China

  • Hou Xian-guang
  • Environmental Science, Geography
    Journal of Paleontology
  • 1999
Five new bivalved arthropods are described from the Lower Cambrian Chengjiang fauna, Yunnan, China, providing new important information concerning the soft bodied and limb characters of the early bivalves.

The place of tardigrades in arthropod evolution

The phylum Tardigrada is an engaging but enigmatic group composed of minute metazoans with four pairs of stubby lobopodous appendages that share important derived characters with arthropods but, as a consequence, the phylogenetic position of the taxon remains uncertain.

Stem group arthropods from the Lower Cambrian Sirius Passet fauna of North Greenland

  • G. Budd
  • Geography, Environmental Science
  • 1998
Discussion of fossil evidence for the origin and early evolution of the arthropods has been dominated for many years by the evidence from the Middle Cambrian Burgess Shale from British Columbia

The "evolution" of Anomalocaris and its classification in the arthropod class Dinocarida (nov.) and order Radiodonta (nov.)

The remarkable “evolution” of the reconstructions of Anomalocaris, the extraordinary predator from the 515 million year old Middle Cambrian Burgess Shale of British Columbia, reflects the dramatic

A death assemblage of priapulid worms from the Middle Cambrian Burgess Shale

  • D. Bruton
  • Geography, Environmental Science
  • 2001
A slab of Burgess Shale (Middle Cambrian), displaying an incomplete exoskeleton of the large arthropod Sidneyia inexpectans and encompassed by nine specimens of the priapulid worm Ottoia prolifica,

The Largest Cambrian Animal, Anomalocaris, Burgess Shale, British Columbia

It is suggested that this animal, the largest known from Cambrian rocks, swam by using the series of closely spaced lateral lobes essentially as a lateral fin along which waves of motion were propagated.

The morphology and phylogenetic significance of Kerygmachela kierkegaardi Budd (Buen Formation, Lower Cambrian, N Greenland)

  • G. Budd
  • Biology, Geography
    Transactions of the Royal Society of Edinburgh: Earth Sciences
  • 1998
The combination of characters found in Kerygmachela allows it to be allied with the lobopods, represented in the extant fauna by the onychophorans, tardigrades, and possibly the pentastomids, and in the Cambrian fossil record by a morphologically diverse set of taxa, some of which are not assignable to the extant groupings.

A Cambrian gilled lobopod from Greenland

  • G. Budd
  • Biology, Environmental Science
  • 1993
The discovery of several 'Burgess Shale'-like faunas in the Cambrian has added significant new data to the debate about the nature of the 'Cambrian explosion', and the data from Kerygmachela may suggest a biphyletic origin for the arthropod grade of organization.

The phylogeny of arachnomorph arthropods and the origin of the Chelicerata

The present study provides a detailed discussion of primary hypotheses of homology and includes a more complete range of terminal taxa than previous analyses, and provides the first convincing synapomorphies for the Arachnomorpha.