Head Segmentation in Early Cambrian Fuxianhuia: Implications for Arthropod Evolution

@article{Chen1995HeadSI,
  title={Head Segmentation in Early Cambrian Fuxianhuia: Implications for Arthropod Evolution},
  author={Jun‐yuan Chen and Gui-qing Zhou and Gregory D. Edgecombe and Lars Ramsk�ld},
  journal={Science},
  year={1995},
  volume={268},
  pages={1339 - 1343}
}
The arthropod Fuxianhuia from the Chengjiang fauna displays primitive aspects of cephalic segmentation and trunk limb morphology that indicate a basal position within Euarthropoda. The cephalon consists of an eye-bearing sclerite that articulates with a head shield bearing antennules and subchelate appendages. Eye stalks, antennules, and subchelate appendages are proto-, deuto-, and tritocerebral limbs and organs, respectovely. The anterior position of the eye-bearing sclerite parallels the… 

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This work documents in the 520-million-year-old Chengjiang arthropod Fuxianhuia protensa an exceptionally preserved bilaterally symmetrical organ system corresponding to the vascular system of extant arthropods, emphasizing complexity that had evolved by the early Cambrian.

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References

SHOWING 1-10 OF 22 REFERENCES

Evidence for Monophyly and Arthropod Affinity of Cambrian Giant Predators

TLDR
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.

Homologies in Cambrian Onychophora

TLDR
New morphological evidence and homology analyses for several characters indicate an anteroposterior reversal of Hallucigenia and Microdictyon, and the taxonomic confusion surrounding the supposed radiolarian family Eoconchariidae is cleared.

The Arthropod Sidneyia Inexpectans, Middle Cambrian, Burgess Shale, British Columbia

TLDR
Evidence suggests that Sidneyia was a bottom-living, carnivorous animal eating larger and harder food than trilobites, and its body plan and absence of chelicera distinguishes Sidneyia from this group.

A Burgess shale-like fauna from the Lower Cambrian of North Greenland

The 'Cambrian explosion' refers to the major adaptive radiation of the metazoans during the earliest Phanerozoic, an event that is best known by the abrupt appearance of hard parts near to the

Composition and preservation of the Chengjiang fauna –a Lower Cambrian soft‐bodied biota

The Lower Cambrian Chengjiang fauna is reviewed and shown to be closely comparable with the younger Burgess Shale fauna. but with various differences in detail. A diverse group of more or less

Morphological disparity in the cambrian.

TLDR
An analysis of the range of morphology among arthropod demonstrates that disparity among living arthropods is similar to that in Cambrian arthropoda, suggesting that special evolutionary processes may not be necessary to explain the early radiation of the metazoans.

Functional Morphology of Feeding and Grooming in Crustacea

A classification system for crustacean setae based on the homology concept decapod crustacean grooming gill and embryo grooming in lithodid crabs grooming structure and function in some terrestial

The Early Evolution of Metazoa and the Significance of Problematic Taxa

TLDR
The Origin of metazoans: a phylogeny deducted from sequences of the 28S ribosomal RNA and problems of arthropod phylogeny with some notes on taxa of doubtful affinities, and a new approach to analyzing problematica.

New constraint on the division of Cambrian time

A U-Pb zircon age of 530.7 ±0.9 Ma for a volcanic ash in the lower Placentian Series of the Avalonian terrane in southern New Brunswick provides a precise point for calibration of Early Cambrian

Fibroblasts as efficient antigen-presenting cells in lymphoid organs.

Only so-called "professional" antigen-presenting cells (APCs) of hematopoietic origin are believed capable of inducing T lymphocyte responses. However, fibroblasts transfected with viral proteins