Spirula—a window to the embryonic development of ammonoids? Morphological and molecular indications for a palaeontological hypothesis

@article{Warnke2005SpirulaaWT,
  title={Spirula—a window to the embryonic development of ammonoids? Morphological and molecular indications for a palaeontological hypothesis},
  author={K. Warnke and H. Keupp},
  journal={Facies},
  year={2005},
  volume={51},
  pages={60-65}
}
Nautilus is not suitable as a model organism to infer biological functions, embryonic development, or mode of life in ammonoids. A brief review of the available morphological data is given and molecular data are added to discuss the usefulness of Spirula as a biological proxy for ammonoids. Indeed, there are many morphological hints indicating that Spirula could be a useful model organism for approaching the embryonic development of ammonoids. The molecular data seem to support this hypothesis… Expand

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References

SHOWING 1-10 OF 46 REFERENCES
Analysis of a Carboniferous embryonic ammonoid assemblage implications for ammonoid embryology
An embryonic ammonoid assemblage was discovered in a carbonate concretion recovered from a dysoxic, relatively offshore marine shale of Virgilian (Upper Pennsylvanian) age in Kansas, USA. TheExpand
The mode of life in ammonoids
The following structural features clearly indicate that ammonoid shells were adapted to withstand considerably higher hydrostatic pressures thanNautilus shells: (1) the corrugated and marginallyExpand
Recent Studies on Spawning, Embryonic Development, and Hatching in the Cephalopoda
TLDR
Some of the most intriguing questions in cephalopod biology are related to those forms that produce eggs of extremely large size, and this chapter gives a brief overview of these recent studies placing them in the chronological sequence of embryogenesis. Expand
Biology of early life stages in cephalopod molluscs.
TLDR
Investigations into dispersal and recruitment are of particular interest to fishery biology, but they are also important for ecological biogeography. Expand
Nautilus—a poor model for the function and behavior of ammonoids?
TLDR
Reexamination of the evidence indicates that static stability should not play a role in the swimming of ammonoids with long body chambers, and functional arguments suggest that a coleoid-like swimming mechanism should have evolved prior to the loss of the body chamber in coleoids. Expand
Major divisions of the Cephalopoda
TLDR
Factual and theoretical evidence combine to suggest that many of the features of the Dibranchiata may have developed in their ancestors included in the Nautiloidea, and that many in Nautilus are derived, or possibly connected with, crucial changes in mode of life now known to have occurred in its ancestry. Expand
The Position of the Ammonoidea within the Cephalopoda
TLDR
It is still worth the effort to state more precisely the position of the Ammonoidea within the Coleoidesa clade (= Neocephalopoda) using a cladistic approach. Expand
Juvenile goniatite survival strategies following Devonian extinction events
  • M. House
  • Geology
  • Geological Society, London, Special Publications
  • 1996
Abstract During the Devonian there is a correlation between certain periods of sedimentary perturbations, often associated with hypoxia, and extinction events in the evolution of the goniatite andExpand
A Late Carboniferous Spirulid Coleoid from ahe Southern Mid-Continent (USA)
Ultrastructural study of a longiconic cephalopod, formerly described as Bactrites postremus (Miller, 1930; Mapes, 1979), reveals that the shell wall, consisting of two prismatic layers and lacking aExpand
Dimorphismus bei Ammoniten der Ahrensburger Lias-Geschiebe
SummaryGlacial drift deposits in the Hamburg area contain a microconch and a macroconch form of the Ammonite genusEleganticerasS. S. Buckman 1913 of lower Toarcian age. They are described and closelyExpand
...
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2
3
4
5
...