Fun Poll: Which of these would you like to see discovered?

[Phil]

Nipponites mirabilis was certainly one of the weirdest ammonites as can be seen from the link and the picture. It demonstrates possibly the most extreme derivation from the classic spiral shell shape amongst all of the ammonoidea, even amongst the heteromorphs. It looks like an irregular tangle of whorls but is really just an interconnecting mass of U-bends

It was a very late ammonite, it lived in the late Cretaceous and has been found in Hokkaido, Japan, and in North America implying it had a very widespread distribution. It has been speculated that this ammonite lived in the surface waters drifting at a shallow depth and feeding on plankton. The ‘head’ was probably angled downwards as it seized small animals with its arms. Given the shape of the shell it must have been a poor swimmer and probably had a lifestyle similar to a jellyfish. The animal must have rolled as it grew and probably had a changing orientation as it developed.

Good choice, Kevin.

(I love the way people always pick the weirdest animals!)

 

[Fujisawas Sake]

Phil,

Is that type of above mentioned change of orientation similar to gastropod torsion? Do you think the viscera and everything would have also changed as well?

These ammonite shell designs get weirder and weirder...

John

 

[Colin]

I had to vote 'other'

okay its not a ceph but what a buzz to see one of these cruising about!!!

Carcharodon megalodon!!!!!!!!!!!!!!!

That's my vote!

 

[Phil]

Colin,

Megalodon? Personally I think we are better off without those! Amazing to think they are known from the teeth alone; no other body parts have been recorded, as far as I know. Very impressive animal though.....from a distance.

John,

Good question; and I admit I am not able to answer it off the top of my head to be honest. I'll have to do a bit of research first. However, I can tell you that Nipponites is believed to have evolved from helically coiled ammonites such as is represented by Bostrychoceras. You may like to have a look at the family of ammonites known as Nostoceratidae, these contain many of the strangest heteromorphs.

I just can't imagine Nipponites growing and maintaining the same orientation. The thing must have twisted as chambers were added; the axis of orientation must have been forever shifting.

Some of these bizarre heteromorphs were not the specialised end-lineages they appear to be, some of the uncoiled or partially coiled heteromorphs in the Lower Cretaceous produced descendants with normal or near-normal coiling.

I apologise, that was not much of an answer for you.

 

[Fujisawas Sake]

Phil,

No, I think that was a pretty darn good answer. I think that torsion might betray a more direct evolutionary link between cephs and gastros. Only time will tell.

I'll have to look more up on my ammonites...

John

 

[chrono_war01]

I voted for other. Bring back the ( I used this since I can't spell)
Since they live in shallow water back, then we can see how they evolved into the ones we have now. Plus, beachgoers would have a lot more fun!

 

[Phil]

I voted for other. Bring back the ( I used this since I can't spell)
Since they live in shallow water back, then we can see how they evolved into the ones we have now. Plus, beachgoers would have a lot more fun!

A good choice, Chrono!

You know, a couple of years back a number of beaks of animal called Provamproteuthis were recovered from the stomachs of some Cretaceous plesiosaurs from Japan. They were about twice as large as the modern Vampire squid and lived in much shallower water as the plesiosaur is not believed to have been a deep diving animal. It would be really interesting to see these animals and try and work out how, when and why the Vampire took the plunge into the dark......

 

[chrono_war01]

From big lump that lives in shallow water to small midget lump in deep water. ( Actually deep water would be an understatment)

 

[H. lunulata]

it would be cool if we could do that

 

[monty]

I just can't imagine Nipponites growing and maintaining the same orientation. The thing must have twisted as chambers were added; the axis of orientation must have been forever shifting.

I thought orientation was one of the few things we can determine accurately, by looking at the "bathtub ring" left by the cameral fluid in the chambers... I don't know the specifics for Nipponites, but I read about this in the geology library at some point when I was avoiding real work or something, and it seemed like this had been done pretty exhaustively for all the various shapes of chambered cephalopods...

 

[Phil]

I thought orientation was one of the few things we can determine accurately, by looking at the "bathtub ring" left by the cameral fluid in the chambers... I don't know the specifics for Nipponites, but I read about this in the geology library at some point when I was avoiding real work or something, and it seemed like this had been done pretty exhaustively for all the various shapes of chambered cephalopods...

Yep, I think you are right about the cameral deposits Monty. Much work has been done on this, much of which involves complicated mathematics, in which case my brain just goes into immediate shutdown. However, here's a link to one such article which deals with early ammonoids, their orientation and locomotion. You will need Adobe Acrobat pdf reader to read it though:

Origin of ammonoid locomotion by Christian Klug and Dieter Korn (2004)

And here is another, very readable, examination of ammonoid heteromorph orientation for you. It includes some nice little animations:

BODY POSITION AND THE FUNCTIONAL MORPHOLOGY OFCRETACEOUS HETEROMORPH AMMONITES by Neale Monks and Jeremy Young.

I think Nipponites is believed to have rolled as it grew as its centre of gravity must have constantly shifted before the final body chamber grew. I'm not sure what work has been done specifically on Nipponites, and I expect that most of it has been in Japan, but I'll keep an eye out for you if I find anything interesting.

 

[Rona]

For some reason that escapes me, I cannot quote other people's messages, but I gotta agree with Colin... Megaladon!!! A shark the size of my house would definitely impress me.

 

[erich orser]

When I was marooned along the backwater shores of the Chesapeake, my friends from California would want to spend all of their time searching our local cliffs and beaches for megalodon teeth! Found amazing amounts of other fossil sharks' teeth, porpoise earbones, dental bits from skates, but local megalodon finds proved elusive. They turned-up in local antique stores in the jewelry cabinets all the time, however. Alas, none of the local clay was quite old enough for exotic cephs.

 

[Snafflehound]

I wouldn't mind a plesiosaur

 

[chrono_war01]

who wouldn't mind. Might be a new stable diet, after we've exhuasted the world's fisheries.