A palaeontological solution to the arthropod head problem

@article{Budd2002APS,
  title={A palaeontological solution to the arthropod head problem},
  author={Graham E. Budd},
  journal={Nature},
  year={2002},
  volume={417},
  pages={271-275}
}
  • G. Budd
  • Published 16 May 2002
  • Environmental Science
  • Nature
The composition of the arthropod head has been one of the most controversial topics in zoology, with a large number of theories being proposed to account for it over the last century. Although fossils have been recognized as being of potential importance in resolving the issue, a lack of consensus over their systematics has obscured their contribution. Here, I show that a group of previously problematic Cambrian arthropods from the Burgess Shale and Chengjiang faunas form a clade close to crown… 

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TLDR
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Pycnogonid affinities : a review

TLDR
Morphologically some characters – the presence of gonopores on the trunk and absence of a labrum, nephridia and intersegmental tendons – support Cormogonida (Euarthropoda excluding pycnogonids), yet even the putative autapomorphy of chelicerae needs to be treated with caution.
...

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