An epipodite-bearing crown-group crustacean from the Lower Cambrian

@article{Zhang2007AnEC,
  title={An epipodite-bearing crown-group crustacean from the Lower Cambrian},
  author={Xi-guang Zhang and David J. Siveter and Dieter Waloszek and Andreas Maas},
  journal={Nature},
  year={2007},
  volume={449},
  pages={595-598}
}
Crown-group crustaceans (Eucrustacea) are common in the fossil record of the past 500 million years back to the early Ordovician period, and very rare representatives are also known from the late Middle and Late Cambrian periods. Finds in Lower Cambrian rocks of the Phosphatocopina, the fossil sister group to eucrustaceans, imply that members of the eucrustacean stem lineage co-occurred, but it remained unclear whether crown-group members were also present at that time. ‘Orsten’-type fossils… 

Exceptionally preserved crustaceans from western Canada reveal a cryptic Cambrian radiation

TLDR
Diverse crustacean appendages of Middle and Late Cambrian age from shallow-marine mudstones of the Deadwood Formation in western Canada provide the earliest evidence for crown-group branchiopods and total-group copepods and ostracods, extending the respective ranges of these clades back from the Devonian, Pennsylvanian, and Ordovician.

A eucrustacean from the Cambrian ‘Orsten’ of Sweden with epipods and a maxillary excretory opening

The Cambrian species Paulinecaris siveterae n. gen. n. sp., known from two trunk fragments, represents the first record of epipods (serving as gills and osmoregulatory structures) in a crustacean

Early fossil record of Euarthropoda and the Cambrian Explosion

TLDR
While each of the major types of fossil evidence have their limitations and are incomplete in different ways, when taken together they allow a coherent picture to emerge of the origin and subsequent radiation of total group Euarthropoda during the Cambrian.

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

TLDR
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.

The importance of lithographic limestones for revealing ontogenies in fossil crustaceans

TLDR
A summary of the occurrences of crustacean fossils providing developmental information and a demonstration of the potential of the lithographic limestones in this context are presented.

Burgess Shale fossils shed light on the agnostid problem

TLDR
Soft tissues from mature individuals of the agnostinids Peronopsis and Ptychagnostus from the middle Cambrian Burgess Shale are described, implying that crustacean-like morphologies evolved homoplastically.
...

References

SHOWING 1-10 OF 31 REFERENCES

The origin of crustaceans: new evidence from the Early Cambrian of China

  • J. ChenJ. VannierD. Huang
  • Environmental Science
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2001
TLDR
This new fossil evidence supports the remote ancestry of crustaceans well before the Late Cambrian and shows, along with other fossil data, that a variety of body plans already coexisted among the primitive crustacean stock.

Upper Cambrian stem-lineage crustaceans and their bearing upon the monophyletic origin of Crustacea and the position of Agnostus

TLDR
Three new arthropods in uncompressed condition have been discovered in Upper Cambrian limestone nodules of Vastergotland, Sweden and their morphology provides new insights into the evolutionary path and progressive development of ground plan characteristics along the stem-lineage and gives further support for the monophyletic origin of Crustacea.

The Upper Cambrian Rehbachiella and the phylogeny of Branchiopoda and Crustacea

TLDR
This study on Rehbachiella supports the monophyly of the crown-group Crustacea and reveals that only the first maxilla was morphologically and functionally included into the crustacean head, while subsequent limbs were addted to the head in a stepwise manner and became modified separately within the different crustacea lineages, which is of great relevance when evaluating the relationships between these.

Crustacea and Arthropod Relationships

TLDR
This work presents a cladistic analysis of the extant superfamilies of the subclasses Myodocopa and Podocopa (Crustacea: Ostracoda) and examines the position of crustaceans within the Arthropoda within the Metazoa on the basis of morphology.

The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life

TLDR
The Chengjiang Biota is a model for the future distribution and Evolutionary Setting of Phylum Uncertain, which will help clarify the role of “superficial”organisms in the evolution of species.

Evolutionary developmental biology of Crustacea

TLDR
PREFACE INTRODUCTION Bauplane versus Ground Patterns, Phyla versus Monophyla: Aspects of Patterns and Processes in Evolutionary Developmental Biology, G. Scholtz, and The Development of the Crustacean Nervous System.

Reflections on the Phylogenetic Position of the Cephalocarida

TLDR
The phylogenetic position of the Cephalocarida is re-evaluated in the light of the recently discovered Orsten (Upper Cambrian) crustaceans, the living Remipedia, and new interpretation of the Paleozoic ‘trilobitomorphs’.

Cell lineage analysis of the mandibular segment of the amphipod Orchestia cavimana reveals that the crustacean paragnaths are sternal outgrowths and not limbs

TLDR
The results show the power of cell lineage and clonal analyses for inferences on the nature, origin and thus homology of morphological structures and their important role in the formation of the feeding apparatus as a highly specialized chewing chamber in adults of crustaceans, myriapods, and hexapods.

Biomechanics of Filter Feeding in the Antarctic Krill Euphausia Superba: Review of Past Work and New Observations

TLDR
Previous work is reviewed and new observations on the morphology and mechanics of the thoracic endopodites and exopodite of Euphausia superba are presented, which suggest that reconsideration of the biomechanics of filter feeding is in order.