Hi Ken
 
Joe here. Yes, straight cones are the same as 'most' straight cephalopods. 'Most',
because they usually exclude the Belemnites and straight ammonites such as Baculites.
 Your Endoceras must have been real nasty. I checked quickly on cephalopod sizes. The
current Giant Squid, Architeuthis, is reported up to 20 meters in length. The fossil
actinoceratoid (cone) Rayonnoceras probably exceeded that when including the tentacles.
Cephalopods were the dominant large predators in ancient seas. Slowly displaced by
sharks. Maybe its best the large 'Cones' are extinct as the shell collector could have
only stuffed a couple in the garage and you can imagine trying to clean one.
 
        Spending many years in Atlantic Canada and hearing the stories of Newfoundland
fisherman, I must add that the fishermen would claim that the Giant Squids caught to date
are only 'babies' and that you 'should have seen the one that got away'.
 
                                                Joe,
                                                Calgary.
 
Ken Zentzis wrote:
 
> Hi Joe and Andrew,
>
> I've enjoyed the discussion of fossil cephalopods. Below you mention straight
> "cones"...would this be the same as "straight cephalopods" (a term with which
> I'm familiar)? In Minnesota I've seen specimens of Endoceras sp. (Ordovician,
> Decorah Shale) 8 feet long, and also sections which would belong to examples
> much longer (by virtue of their diameter). Specimens up to 14 ft. have been reported.
>
> Ken Zentzis
> Wichita, Kansas
>
> NORA BRYAN wrote:
> >
> > Hi Andrew,
> >
> > Joe here (on Nora's E-mail).
>
> >             As for 'giant' ammonites. There are a few specimens in the
> > Jurassic here in Alberta that approach the 6 foot size in diameter. They
> > have not been collected as they are in matrix at remote sites.  Now we
> > will have to find one over 8 feet.  I do believe, however, that some
> > straight 'Cones' were much larger; I will try and find a reference.