• Welcome to TONMO, the premier cephalopod interest community, and birthplace of #WorldOctopusDay and #CephalopodAwarenessDays. Founded in 2000, we are a large community of experts, hobbyists and enthusiasts, some of whom come together when we host our biennial conference. To join in on the fun, sign up. You can also become a Supporter for just $50/year to remove all ads and enjoy other perks. Follow us on Twitter for more cephy goodness.

[Old Board Archive] Vampyroteuthis Question (and ammonites)

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,033
This is something I have just made up so please utterly dismiss this if you think that is appropriate!

If the lappets were indeed used for display purposes in order to attract a mate, then it naturally follows that the ammonite must have had well developed eyes in order to recognise visual signals and, as Steve suggests, a well developed brain able to interpret these signals. Species with lappets must have been fairly shallow water creatures as a physical display structure would be pointless in the abyss with little light to penetrate in order for the structure to be seen. Can we therefore assume that the fleshy head of the ammonite must have had a much closer affinity to the coleoids in structure? Eyes such as possessed by the nautilus would, I assume, be unable to determine fine detail due to their basic structure yet the much more advanced squid or octopus type eyes would be able to do so.

The soft body part of the belemnite certainly bears a close resemblance to the squid. It would be interesting to know how closely the two groups are related to see if any parallels could be drawn in their respective soft-bodied anatomies.

I know my little theory of the ammonite possessing a coleoid head as opposed to a nautiloid rests on a number of assumptions, what does anyone else think?

Kevin - I did some hunting around for the book you mentioned. The cheapest I could find was over $200! Ouch. A bit out of my price range, unfortunately.

Confused, as ever,

Phil
 

Steve O'Shea

TONMO Supporter
Registered
Joined
Nov 19, 2002
Messages
4,671
Totally logical stuff Phil!

I've probably asked this before, but are there any traces of muscle-attachment scars inside the aperture of ammonite shell (to have held the animal in)?
Cheers
O
 

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,033
Steve, apparantly muscle scars are occasionally found and present the only direct evidence we have as to the soft bodied creature itself. These scars are normally located at the rear of the final septum. There is a brief reference to them here: (go to the end of the article). Muscles are allegedly attached in long and thin strips though I've yet to find a photo of this:

http://www.nhm.ac.uk/hosted_sites/pe/1998_1/monks/intro.htm

Alternatively, an obscure paper was written on scar attachments in 1898 by a Victorian gentlemen known as Crick:

Crick G. C. 1898. On the muscular attachment of the animal to its shell in some Fossil Cephalopoda (Ammonoidea). Transactions of the Linnaean Society of London (Zoology), 7: 71-113

As this paper was quoted in the above recent article it must still be of great value beside being over a century old.

I hope that this is a useful pointer. I'm sure Kevin can provide some interesting info!

Phil
 

Steve O'Shea

TONMO Supporter
Registered
Joined
Nov 19, 2002
Messages
4,671
Phil said:
These scars are normally located at the rear of the final septum. Muscles are allegedly attached in long and thin strips though I've yet to find a photo of this:

Real interesting Phil. Having found these muscle scars I'm sure there's another set to be located. The scars at the rear of the final septum, if the animal was encased within the shell, would have to be the points of attachment of some retractor muscle system (to pull the rear on the animal, or part of its anatomy, likely the gizzard, inside the last chamber). To counter this, if the animal was truly encased within that last chamber, there must also be an opposing set of muscles, protractors, with points of attachment (and associated muscle scars) probably located towards the edge of the last chamber (to pull the animal back out again). Are you familiar with any reference to these/any such scars?

Sorry to keep asking these questions ... real nice link you gave by the way!
Cheers
Steve
 

Architeuthoceras

Architeuthis
Staff member
Moderator
Joined
Nov 19, 2002
Messages
2,442
attachment scars

The photos below show possible muscle scars. The small arrows point to the approximate location of the last septum, or at least the point where the mature modifications of the shell begin. So this would be the back of the final living chamber. I am not sure these are muscle scars but there is some kind of structure there made before the animal had finished the shell, as if it knew where it was going to finally attach it's muscles. These are internal molds without any shell material left.

An interesting note about Phils avatar. Until recently parts of anomalocaris were parts of 3 different animals, the body was one animal, the mouth another and the appendages another. until the complete animal fossil was found. Someday someone will find the fossil or fossils of an ammonoid that will clarify all.
:nautilus:
 

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,033
Thanks Kevin. They were interesting photos. Just how exactly do you determine muscle scars on the surface of those ammonite casts? They look mildly worn, so how do you differentiate between wear and tear and genuine muscle attachments?

If interested there is a much fuller version of the article I referenced above at:

http://216.239.51.100/search?q=cach...ks/text.pdf+"ammonite+anatomy"&hl=en&ie=UTF-8

This version has a discussion and bibliography section.

Glad you like my little Anomalocaris (now Laggania). It's a little clay model I made at home and superimposed onto an appropriate background. I would love to start up a discussion on this bizarre Cambrian predator but as the thing was probably an arthropod and most certainly not a cephalopod I can't really do it here. Perhaps Tony could start up a TONMOCARIS page for us?

Phil
 

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,033
Slightly off the topic in hand, here's a picture of the best of my collection of fossil ceph bits, excepting the recent Nautilus and Spirula shell. You'll find some belemnites and a fossil nautilus in there as well as a few omnipresent ammonites.

Hope you all like it!
 

Nancy

Titanites
Staff member
Moderator
Joined
Nov 20, 2002
Messages
5,772
What a beautiful collection! And you laid them out so well for the photo - it's interesting enough to be a poster!

Thanks, Phil

Nancy
 

Architeuthoceras

Architeuthis
Staff member
Moderator
Joined
Nov 19, 2002
Messages
2,442
Phil, I am not sure those are muscle scars just faint circular structures on the mold, but in the right place?? That is a great collection, and they are all very well preserved, I would have to search for years to find a good specimen like those.
:nautilus:
 

Phil

TONMO Supporter
Supporter
Joined
Nov 19, 2002
Messages
3,033
Thanks Kevin and Nancy.

Actually I did not find all of those ammonites. I can only wish! The larger ammonites, the large belemnite and the Spirula I bought from a fossil shop, though the smaller belemnites and most of the smaller ammonites come from a site at Folkestone in Kent which is only about five miles from me. The clays there are 100 million years old and renowned for exceptional preservation in three dimensions. The chance finding of a few of these on the beach is what interested me in the subject of cephalopods in the first place.

I've got quite a few more smaller ammonites at home but I thought you'd rather see the larger ones.


Cheers!
 

Forum statistics

Threads
20,889
Messages
206,855
Members
8,474
Latest member
Thomasjedlicka

Monty Awards

TONMOCON IV (2011): Terri
TONMOCON V (2013): Jean
TONMOCON VI (2015): Taollan
TONMOCON VII (2018): ekocak


Top