Fossil horseshoe crabs
Created 1 May 1997; Modified 14 February 2001
This page details the critters which I spent about
four years studying formally at the University of Manchester,
and what seems now to be an ongoing concern! If after reading
through this information, you feel that you have something
to add, or something to criticise, I'd like to hear from you.
List of Contents
Introduction
Horseshoe crabs have been around in one disguise or another for quite
some time now, let's just say since the Lower Silurian for arguments
sake. Personally, I reckon they'll outlive that troublesome species
Homo sapiens hands (or at least pincered feet) down.
Why? Well, because they are good at what they do and they don't
seem to have any intention of changing their mode of life or gross
body morphology. This is why they are often refered to as 'Living
fossils'.
H.C. Links
Yes, there are actually a few other links to these beasties.
Here's some for the meantime. I'll arrange them a little better into
subject headings when I get time. If you know of any links which contain,
explain or even have a vague whiff of Horseshoe crab about them, please e-mail me with the details.
for those of you more interested in eurypterids (an extinct aquatic chelicerate), here's a few for you!
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Classification
Xiphosurans are marine aquatic arthropods which are grouped
with the Chelicerates. Other more familiar Chelicerates
include spiders and scorpions (arachnids), and eurypterids
(extinct aquatic arthropods). As more and more sites
yielding exceptionally preserved fossil arthropods turn up
in rocks of Cambrian age, it seems less likely that xiphosurans
and trilobites shared a common ancestor. There are far too
many other better suited candidates.
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Taphonomy of Xiphosurans
Xiphosurans in common with other chelicerates have an
unmineralised exoskeleton of chitinous cuticle.
This is quite unlike the calcium carbonate armour of
trilobites. Consequently, their remains behave slightly
differently during fossil diagenesis. Whereas trilobites
have a widespread occurrence through many different
sediments representing different depositional settings,
xiphosuran fossils are much more restricted in their
occurrence. In fact, they are most often associated with sites
of exceptional preservation, so-called Konservat-Lagerstatten.
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Systematics
This listing is modified from a recent research paper which
I co-authored with my research supervisor, Dr Paul A. Selden.
I have included here the classification down to species level.
However, fossils just keep getting found so the list is bound
to increase!
The Palaeozoic Xiphosura
- Class Xiphosura Latreille, 1802
- Family Weinberginidae Richter and Richter, 1929
- Weinbergina Richter and Richter, 1929
- Weinbergina opitzi Richter and Richter, 1929
- Willwerathia Stormer, 1969
- Willwerathia laticeps (Stormer, 1936)
- Legrandella Eldredge, 1974
- Legrandella lombardi Eldredge, 1974
- Unnamed Taxon 1
- Unnamed Taxon 2
- Bunodes Eichwald, 1854
- Bunodes lunula Eichwald, 1854
- Limuloides Woodward, 1865
- Limuloides limuloides Woodward, 1865
- Unnamed Taxon 3
- Plesion Pasternakevia Selden and Drygant, 1987
- Pasternakevia podolica Selden and Drygant, 1987
- Unnamed Taxon 4
- Plesion Cyamocephalus Currie, 1927
- Cyamocephalus loganensis Currie, 1927
- Plesion Pseudoniscus Nieszkowski, 1859
- Pseudoniscus aculeatus Nieszkowski, 1859
- Unnamed Taxon 5
- Plesion (Family) Kasibelinuridae Pickett, 1993
- Kasibelinurus Pickett, 1993
- Kasibelinurus amicorum Pickett, 1993
- Order Xiphosurida Latreille, 1802
- Suborder Bellinurina Zittel and Eastman, 1913
- Family Bellinuridae Zittel and Eastman, 1913
- Bellinurus Pictet, 1846
- Bellinurus trilobitoides Buckland, 1837
- Family Euproopidae Eller, 1938
- Euproops Meek, 1867
- Euproops anthrax Prestwich, 1840
- Euproops danae Meek and Worthen, 1865
- Euproops rotundatus Prestwich, 1840
- Liomesaspis Raymond, 1944
- Liomesaspis laevis Raymond, 1944
- Unnamed Taxon 6
- Plesion Bellinuroopsis Chernyshev, 1933
- Bellinuroopsis rossicus Chernyshev, 1933
- Unnamed Taxon 7
- Plesion (family) Rolfeiidae Selden and Siveter, 1987
- Rolfeia Waterston, 1985
- Rolfeia fouldenensis Waterston, 1985
- Suborder Limulina Richter and Richter, 1929
- Superfamily Paleolimuloidea sfam. nov.
- Family Paleolimulidae Raymond, 1944
- Paleolimulus Dunbar, 1923
- Paleolimulus avitus Dunbar, 1923
- Family Moravuridae Pribyl, 1967
- Xaniopyramis Siveter and Selden, 1987
- Xaniopyramis linseyi Siveter and Selden, 1987
- Superfamily Limuloidea Zittel, 1885
- Plesion Valloisella Racheboeuf, 1992
- Valloisella lievensis Racheboeuf, 1992
- Family Limulidae Zittel, 1885
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- Back to the Surgery
Thanks Simon for the formatting of the species list.
For all you off-line browsers, this page address is:
https://members.tripod.com/~Lyall/xipho
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