Ammonoid Correlation & Time Charts

To me, that doesn't sound like a problem whatsoever, no copyright issues with hyperlinking, Fossil Kid, unless you're hyperlinking to beyond a paid subscription type firewall. If you need "official" permission, than good ole' webmeister Tony will have to step in :biggrin2:

He should be up in roughly 3 hours, I'd say...
 
It's the fact you've established it's Cretaceous, otherwise my initial guess would've been Psiloceras psilonotum, which alas is from the Hettangien...

A further clue might be found in the systematic account of the Ammonoidea in the 1966 Geol. Soc. Memoire on the Geology of the country around Canterbury and Folkestone

"Except for the Desmoceratid Beudanticeras, which is common in the mammillatum Zone and occurs frequently in the early beds of the Upper Gault, the "Leiostraca", or smooth ammonites are known only by a few chance finds of Hypophylloceras, Tetragonites, Pictetia, Desmoceras, Puzosia and Uhligella. These ammonites are thought to have preferred open waters and to have had their European centre of dispersal in the Mediterranean region."

The problem obviously being, that your picture is of a much more slender shell than any of the quoted species above...

Is your fossil much eroded? The posted picture is somewhat vague, so I can't make out very specific markings...
 
Super quick question for you:

Ammonites became extinct in which stage of the upper/late Cretacious? Do we know, more or less?

Cenomanian | Turonian | Coniacian
Santonian | Campanian | Maastrichtian

Thanks!
 
Well Toren as far as I understand it, ammonoids survived right up to the end of the Maastrichtian; indeed a few ammonoids have been found in France that have been dated up to a few hundred years(!) before the K-T boundary. However, a paper that was published last year revealed that a few scaphitid ammonites may have soldiered on to the early Eocene by a couple of million years in European waters.

Links to both papers are available in the 'New Papers on Fossil Cephalopods' thread.
 
It's not so much the colours but that amazing LSD inspired OTT painting on the right that disturbs me.

Good chart, have bookmarked it.
 
Latest Zonation for part (most) of the Late Cretaceous of the Western Interior US. Contains a nice history of the zoning of late cretaceous rocks, fun to see how it has changed and been refined.

(about 3M pdf)

Cobban, W.A., Walaszczyk, Ireneusz, Obradovich, J.D., and McKinney, K.C., 2006, A USGS zonal table for the Upper Cretaceous middle Cenomanian−Maastrichtian of the Western Interior of the United States based on ammonites, inoceramids, and radiometric ages: U.S. Geological Survey Open-File Report 2006-1250, 45 p.
 

Shop Amazon

Shop Amazon
Shop Amazon; support TONMO!
Shop Amazon
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
Back
Top