Cephalopod Help

[Peat Burns]

I have an ammonite(?) that I received circa 1990 from a missionary who said that it was "brought down from the mountains by monks" in Papua New Guinea.  Apparently, there is relatively little known about the palaeontology of the area.  There are similar ammonites showing up in native tribal art pendants (see article in "Deposits Magazine" HERE

 

The article indicates that it is not known whether these ammonites that are showing up are recently imported or of local origin.  I suppose mine could have been imported, but given the date of acquisition and what I was told, I am inclined to think it was collected in situ in Papua New Guinea, but I can't be certain.  The geologic map I found did not distinguish between periods in the Mesozoic, so I don't know if it is Cretaceous or Jurassic, etc.

 

I did find 2 papers (Both available as .pdf online): 

Tatsuro, M & S.K. Skwarko. 1991. Ammonites of the Cretaceous Ieru Formation, western Papua New Guinea. J. Australian Geology & Geophysics 12(3): 245-262

Tatsuro, M & S.K. Skwarko. 1993. Cretaceous ammonites from south-central Papua New Guinea. J. Australian Geology & Geophysics 14(4): 411 - 433.

 

The closest resemblance of the taxa in those papers was Subthurmannia (Fauriella) boissieri.  In doing my own searching, I thought Macrocephalites bifurcatus (middle Jurassic) looked like a good match and has been collected in Papua (see link to museum specimen HERE).  The preservation of that specimen appears to match mine, too.

 

Here are some pics of my specimen.  Any help from the ammonite enthusiasts would be greatly appreciated! @Ludwigia

 

[doushantuo]

[doushantuo]

useful?

Faunenhorizonte.pdf

[Ludwigia]

7 hours ago, Peat Burns said:

 

 Any help from the ammonite enthusiasts would be greatly appreciated! @Ludwigia

 

I'm not very familiar with this ammonite fauna realm, since literature is pretty scarce unless you happen to have free access to scientific journals. However I believe from the little evidence that I've seen that you've hit the nail on the head with your assessment as Macrocephalites bifurcatus.

[Miocene_Mason]

I've only ever heard of fossils from there, nice acquisition! Wonder what the monks were doing looking for fossils.

[FossilDAWG]

It looks quite similar to a Macrocephalites I have from British Columbia.  Of course it we don't have the suture line to compare.

 

Don

[Peat Burns]

7 hours ago, Ludwigia said:

I'm not very familiar with this ammonite fauna realm, since literature is pretty scarce unless you happen to have free access to scientific journals. However I believe from the little evidence that I've seen that you've hit the nail on the head with your assessment as Macrocephalites bifurcatus.

 

6 hours ago, WhodamanHD said:

I've only ever heard of fossils from there, nice acquisition! Wonder what the monks were doing looking for fossils.

 

5 hours ago, FossilDAWG said:

It looks quite similar to a Macrocephalites I have from British Columbia.  Of course it we don't have the suture line to compare.

 

Don

Thanks Ludwigia and FossilDawg for the input on this (and to @doushantuo for the paper).  It seems reasonable for now, at least, to label it Macrocephalites cf. M bifurcatus (Middle Jurrassic?) until a specialist can look at it in person.

 

@WhodamanHD My understanding is that the monks were bringing them down to market to sell. The conversation that I had with the missionary who gave it to me happened over 25 years ago, so my recollections have probably eroded a bit.  It was a neat story;  I was studying in the library, and a "non-traditional" student (i.e. not college age) was studying there, too, and somehow we struck up a conversation, and I probably told him at some point of my affinity for fossils.  He then related his story about the monks and the ammonites in New Guinea.  And so jokingly, I said "Get me one when you are there next!", thinking I'd never see him again.  A couple years later, he came back with two ammonites, one for me and one for one of the professors.  He also brought me a beautiful triton shell.  It's definitely a treasured specimen in my collection.  Now that I have the proper prep tools, I may try to expose some of the inner whorls.

 

Thanks again, all.

[Ludwigia]

33 minutes ago, Peat Burns said:

 

 

Thanks Ludwigia and FossilDawg for the input on this (and to @doushantuo for the paper).  It seems reasonable for now, at least, to label it Macrocephalites cf. M bifurcatus (Middle Jurrassic?) until a specialist can look at it in person.

 

@WhodamanHD My understanding is that the monks were bringing them down to market to sell. The conversation that I had with the missionary who gave it to me happened over 25 years ago, so my recollections have probably eroded a bit.  It was a neat story;  I was studying in the library, and a "non-traditional" student (i.e. not college age) was studying there, too, and somehow we struck up a conversation, and I probably told him at some point of my affinity for fossils.  He then related his story about the monks and the ammonites in New Guinea.  And so jokingly, I said "Get me one when you are there next!", thinking I'd never see him again.  A couple years later, he came back with two ammonites, one for me and one for one of the professors.  He also brought me a beautiful triton shell.  It's definitely a treasured specimen in my collection.  Now that I have the proper prep tools, I may try to expose some of the inner whorls.

 

Thanks again, all.

Definitely Middle Jurassic. Could be either Bathonian or Callovian. Check this out if you haven't already seen it:

 

https://books.google.de/books?id=iMus4MtzIl4C&pg=PA185&lpg=PA185&dq=macrocephalites+bifurcatus&source=bl&ots=Xf2xZpBFyN&sig=E2Z3gDArDj5gyZ2XCK9jDHsbJvI&hl=de&sa=X&ved=0ahUKEwjw9LiIqP3WAhVpJMAKHcM2CAQQ6AEIQjAD#v=onepage&q=macrocephalites bifurcatus&f=false