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Horseshoe Crab Death Trail


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Attached is a spectacular ichno / body fossil association showing the final moments of a Solnhofen horseshoe crab. Interestingly, the death trail (Mortichnia) has priority over the maker, so it's labeled accordingly: Kouphichnium walchi instead of Mesolimulus walchi. Fascinating! emo71.gif

 

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Trace fossils and their formers.

In: Boucot, A.J. et al. (1990)

Evolutionary Paleobiology of Behavior and Coevolution.

Elsevier Publishing, 725 pp.

 

 

 

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Pretty neat, thanks for sharing.

I wonder if the tracks had to be prepped or were just present. And do you know if that's a full sized Horseshoe Crab that died of old age or struggled in the muck after being covered? It looks small compared to a modern day Horseshoe, but im not familiar with different species of them.

~Charlie~

"There are those that look at things the way they are, and ask why.....i dream of things that never were, and ask why not?" ~RFK
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What a delicious fossil!

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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Interesting, but I don't know that I agree with that treatment. Trace fossils are rarely (I might say never) so distinctive that only one species could possibly have made them. In this case, is there anything so unique to Kouphichnium walchi as to rule out such tracks being made by any species of horseshoe crab other than Mesolimulus walchi? If I think about modern species, leafcutter bees, of which there are several genera and many species, all make similar traces as they cut segments out of leaves. No-one would advocate lumping all these genera and species under one name just because they leave a similar hole in leaves.

For rules of priority to apply, there has to be an exclusive relationship between the first named taxon and subsequent names, such that what is being named is identical (i.e. the different names all apply to the same organism, and to no other). How can we be sure of that for a trace fossil vs its maker (or one of its makers)?

Don

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On 5/2/2014 at 10:30 AM, fossilized6s said:

Pretty neat, thanks for sharing.

I wonder if the tracks had to be prepped or were just present. And do you know if that's a full sized Horseshoe Crab that died of old age or struggled in the muck after being covered? It looks small compared to a modern day Horseshoe, but im not familiar with different species of them.

 

 

Great observation and question. The asphyxiating environment was probably what caught the juveniles dead in their tracks!

 

Quote

Most common are limulids at the end of their trackways (Kouphichnium; Pl. 6). An experienced quarryman recognizes the pattern and knows exactly in which direction to dig for the prized body fossil. Nor does he have to dig far, because even a sturdy horseshoe crab made it no more than a few meters after touching bottom in the asphyxiating environment. There is only a minor drawback: limulids thus preserved never reach the body sizes recorded by trackways in marginal facies. Probably only juveniles swam up and became swept into the anoxic zone when a turbidity current passed by.

 

Seilacher, A. (2007)

Trace Fossil Analysis.

Springer Publishing, 240 pp.

 

 

 

image.png.a84de26dad44fb03836a743755df237c.png

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Interesting, but I don't know that I agree with that treatment. Trace fossils are rarely (I might say never) so distinctive that only one species could possibly have made them. In this case, is there anything so unique to Kouphichnium walchi as to rule out such tracks being made by any species of horseshoe crab other than Mesolimulus walchi? If I think about modern species, leafcutter bees, of which there are several genera and many species, all make similar traces as they cut segments out of leaves. No-one would advocate lumping all these genera and species under one name just because they leave a similar hole in leaves.

For rules of priority to apply, there has to be an exclusive relationship between the first named taxon and subsequent names, such that what is being named is identical (i.e. the different names all apply to the same organism, and to no other). How can we be sure of that for a trace fossil vs its maker (or one of its makers)?

Don

An excellent argument. This seems to be a case of the divide between precision (of the system) and accuracy (of the systematics). I am conservative in this respect, and would rather be half-right than wrong. ;)

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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On 5/2/2014 at 10:43 AM, FossilDAWG said:

Interesting, but I don't know that I agree with that treatment. Trace fossils are rarely (I might say never) so distinctive that only one species could possibly have made them. In this case, is there anything so unique to Kouphichnium walchi as to rule out such tracks being made by any species of horseshoe crab other than Mesolimulus walchi? If I think about modern species, leafcutter bees, of which there are several genera and many species, all make similar traces as they cut segments out of leaves. No-one would advocate lumping all these genera and species under one name just because they leave a similar hole in leaves.

For rules of priority to apply, there has to be an exclusive relationship between the first named taxon and subsequent names, such that what is being named is identical (i.e. the different names all apply to the same organism, and to no other). How can we be sure of that for a trace fossil vs its maker (or one of its makers)?

Don

 

 

Great discussion! I found these excerpts from a recent paper to help clarify the methodology of attribution:

 

Quote

The limulid ichnogenus Kouphichnium is quite common during the Late Jurassic. It was described by Nopsca (1923) and is based on the type ichnospecies Ichnites lithographicus Oppel, 1862 from Solnhofen. In 1964, Malz coined the specific name Kouphichnium walchi to the tracks of a dying limulid (mortichnia), also from Solnhofen.

 

Both Kouphichnium and M. walchii are recorded in Solnhofen and Cerin. If M. walchii is responsible for the mortichnia K. walchi, we can assume that the same species is very likely the trackmaker of a part or the entire ichnogenus Kouphichnium, at least in the Upper Jurassic of western Europe. We tentatively refer the trackmaker of Canjuers to M. walchii, although we are aware that K. walchi, being part of a parataxonomy, is related to body fossils as well as tracks. We also acknowledge that the trackmaker could also be another species, not described yet. Indeed, extant limulid species are geographically isolated but have the same ecology, morphology (Shuster, 1982) and serology (Shuster, 1962). This implies that they could have coexisted during the Late Jurassic. The discovery of limulid specimens in Canjuers would reset our hypothesis.

 

So far, it is likely that the species M. walchii was the trackmaker. The tracks could illustrate an important connection between the Canjuers lagoon and the Tethys, or a spawning behavior, leading to a temporary introduction of typical marine animals in the lagoon.

 

Peyre de Fabrègues, C., & Allain, R. (2013)

A limulid trackway from the Late Jurassic (Tithonian) Lagerstätte of Canjuers (Var, France).

Comptes Rendus Palevol, 12(4):181-189

 

 

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On a more etherial level, I'm enthralled by a fossil in 4 dimensions.....one that displays a record of ancient life in the normal 3, with a function of time apparent on a human scale rather the geologic. Any low tide explorer can place himself in the last hour of it's life.

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Are y'all saying that a body fossil can be renamed for its trace (but only if the trace were named first)?? So if I wrote a paper naming this thing:

post-4372-0-64030300-1399326275_thumb.jpg

say, Haslamichnus chemainusensis, and then someone else wrote a paper describing a new genus/sp of worm, clam, whatever... and then later the trace and body fossil were found connected, then my Haslamichnus chemainusensis name would have to be applied to that body fossil? Even though the -ichnus suffix clearly refers to a trace rather than a body?

Why don't they just keep ichnofossils separate, with separate names, from body fossils? I would see no problem with saying, forevermore, that Kouphichnium was caused by Mesolimulus.

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That one was featured in David Attenborough's Lost World, Vanished Lives - The Rare Glimpses. Its an awesome fossil!

Edited by JimB88
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Great fossil!

----------------------------------------------------------------------------

:popcorn: John

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  • 8 months later...

hey all,

Ichnotaxonomy is kind of my "thing", and I specifically work on Kouphichnium these days. Body fossils are indeed kept separate from ichnofossils. This is nessessary for all kinds of reasons but primarily one animal can make numerous types of traces.... and one type of trace can be made by multiple animals. A good example is Rusophycus ( a classic). This trace is now known to be made by trilobites but also shrimp-like animals as well. Much the same as Kouphichnium is made by numerous genera of horseshoe crabs datign back to early xiphosurans in the Silurian. This trace has been innacurately labeled and has been dealt with in a few papers since it was published. This is a kouphichnium ichnofossil that terminates in body fossil of Mesolimulus.

The law of priority is only applicable if you have 2 fossils that are the same species and thus whichever was named first carries the name as the senior subjective synonym and the other becomes the Junior subjective synonym and is abandoned. a species may also be reassigned to a new or preexisting genus if it was placed in the wrong basket.But according to the Zoological Code for Nomenclature ( which has its own section for trace fossils) traces are to be considered separate from the body fossils. It gets tricky when you have compound fossils. One grading into another in the ichnology realm. For example a Cruziana with numerous Rusophycus along the trail or a Kouphichnium with numerous Selenichnites / Limulocubichnous along the trail. Underprint fall-out or substrate variations such can also get complex taxonomically. For example with a tetrapod trackway changing to a swim trace. We tend to assign multiple names in these cases as a comound trace includes two or more morphologicaly distinct or more importantly, exhibit differnt behaviors (ie Kouphichnium x Selenichnites). There is still lots of discussion in the literature how to handle these gradations, but it is very clear that body fossils and traces are indeed named separately. Hope this clarifies a bit :)

cheers

Are y'all saying that a body fossil can be renamed for its trace (but only if the trace were named first)?? So if I wrote a paper naming this thing:

attachicon.gifChemInchnoShr.jpg

say, Haslamichnus chemainusensis, and then someone else wrote a paper describing a new genus/sp of worm, clam, whatever... and then later the trace and body fossil were found connected, then my Haslamichnus chemainusensis name would have to be applied to that body fossil? Even though the -ichnus suffix clearly refers to a trace rather than a body?

Why don't they just keep ichnofossils separate, with separate names, from body fossils? I would see no problem with saying, forevermore, that Kouphichnium was caused by Mesolimulus.

  • I found this Informative 1
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...This trace has been innacurately labeled and has been dealt with in a few papers since it was published. This is a kouphichnium ichnofossil that terminates in body fossil of Mesolimulus...

Could you please cite those papers for this thread? Thanks for the update!

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Here is a good figure from one of those recent papers. Applying both species is certainly more logical and a lot less confusing. Great thread!

 

IMG1.jpg

 

Diedrich, C.G. (2011)

Middle Triassic horseshoe crab reproduction areas on intertidal flats of Europe with evidence of predation by archosaurs.

Biological Journal of the Linnean Society, 103(1):76-105

 

 

 

image.png.a84de26dad44fb03836a743755df237c.png

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Here is a good figure from one of those recent papers. Applying both species is certainly more logical and a lot less confusing. Great thread!

attachicon.gifIMG1.jpg

Diedrich, C.G. (2011)

Middle Triassic horseshoe crab reproduction areas on intertidal flats of Europe with evidence of predation by archosaurs.

Biological Journal of the Linnean Society, 103(1):76-105

Thanks, you beat me to it :) This is certainly a good one! Great sketch of the traces as well!

M

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