Here's some more contenders under consideration for my first ammonite. These were shown in Room 152 by British Jurassic Fossils. Above left and right are two Asteroceras sp specimens from the Frodingham Ironstone. Both are approximately 8 cm in diameter and both were priced at $50. Note the difference in color due to differences in the surrounding environment as the mineralization of them occurred.
BTW, if you're thinking 'big snails' regarding ammonites, you've got the wrong picture. While Ammonites share the same Phylum, Mollusca, they are Cephalopods, belonging to the extinct order Ammonoidea, which is related to the present day squid, octopus and nautilus. Ammonites were very mobile and intelligent, and they were hunters and predators as well as prey for other types of ancient creatures, including other ammonites. Ammonites were also social and most species appear to have shoaled or schooled, living together in colonies of hundreds to thousands of individuals.
Here's some best guess ammonite reconstructions which were displayed at Fossil Hall in the Ballroom at the Ramada Inn. Hey, so what's not to love - who can resist such personable cuties with those big, beautiful, intelligent peepers?
Now, picture thousands of these in a free-swimming pack hunting you with those sucker covered tentacles frantically grasping for a hold and those powerful shell and bone crushing beaks ravenously chopping away your flesh and bones, and you'll be starting to get the picture...
British Jurassic Fossils in showed this selection of pyritized Dactylioceras comune ammonites from the Jurassic, Upper Lias Formation near Whitby, North Yorkshire, England. These are approximately 165 million years old. You could take your pick of these for $30 and I thought the piece in I'm showing in hand above right to be the best of the lot. The 7 cm diameter shell has been replaced by pyrite and it showed fine detail on its ribs all the way down to the ammonitella at the center of its phragmocone. I considered the metallic luster of these Dactylioceras to be very aesthetic against the light grey matrix in which they are found. These seemed relatively ubiquitous and a number of other dealers where also showing these ammonites, sometimes for less money, but their pyritized Dactylioceras comune specimens generally lacked the size, fine detail and overall quality of the spread available at British Jurassic Fossils.
Ammonites are still mysterious with much to be learned regarding them by the scientific community. Ammonites were extremely diverse, fast evolving and long lived as an order. While greatly diminished and nearly extincted at several points in their long history, by and large the ammonites flourished vigorously throughout ancient oceans from the Paleozoic era up until the end of the Mesozoic era. They first appear in Late Silurian strata about 400 million years ago and endured as an order through the Late Cretaceous until the mass extinction event that also wiped out the dinosaurs about 60 million years ago, a reign on Earth of over 300 million years. In spite of the fact that millions of ammonite fossils have been recovered world wide, so far no one has discovered an ammonite with preserved arms, tentacles or much of the other soft body parts. So much of what is understood and known about the ammonites is inferred and extrapolated from contemporary cephalopods.
British Jurassic Fossils Tel: 44.1724.732274 Fax: 44.1724.732272 118 North Street, Winterton, Nr. Sconthorpe, No. Linconshire, DN15 9QN, England
Above left, Placenticeras meeki from the Campanian Stage, Upper Cretaceous, Bearpaw Formation, Dawson County, Montana. 20 inches overall, shell 16 inches in diameter. $3800. Close up of suture pattern above right.
Above left, Arietites sp, 27 inches in diameter, $4,500. Above right, Peltoceras athleta, Upper Callouium, Dogger Formation, Middle Jurassic approximately 180 million years ago, Tours, France.
Above left Perisphinctes sp, Dogger Formation, England. 5.5 inches (14 cm) in diameter. $30. Above right, Perisphinctes sp, Jurassic, Malm Formation, Tulear, Madagascar. 8.75 cm. $12.
Mineralien Zentrum Email: firstname.lastname@example.org Tel: 040.369003.11 Fax: 040.369003.10 Steintwiete 11, 20459 Hamburg, Germany
Above left, Asteroceras obtusm, Jurassic, Lower Lias, Sinemurian, Charmouth, Dorset, UK. $90. Above right, Parkinsonia sp, Inferior Oolite, Dorset, GB. $60.
Above left, Esericeras sp, Lower Lias, Fugerrolles, Caluados, Normandy, France. 10.5 cm. $50. Above right, Phylloceras sp, Inferior Oolite, Lower Jurassic, Madagascar. 6.5 cm, $45.
At right, Epimayaites sp, Upper Jurassic, France. 8 cm, $100
Rock Art of the UK Tel: 44.1162.664684 Fax: 44.1162.661101 4 Gipsy Lane, Leicester, LE4 6RB, England
Baculite sp, approximately 5 inches, South Dakota, $95.
Elk Creek Fossils Tel: 605.787.5325 HC 80 Box 720-50, Piedmont, SD 57769
L&J Fossils Tel/Fax: 316.575137 Peter-Roseggerstrabe 38a, 8053 Graz, Austria
The Bone Room Web: The Bone Room Tel: 510.526.5252 1569 Solano Avenue, Berkeley, CA 94707
Xiphactinus audax, mount 16 feet x 5 feet, specimen 15 feet, $29,500. Sold to a Spanish Museum.
Warfield Fossils Tel and Fax: 307.883.2445 2072 Muddy String Road, Thayne, Wyoming 83127
Crystal World & Prehistoric Journeys Tel 613.970.5777 Fax: 613.9701.5945 20 FiveWays Boulevard, Keysborough, Victoria, Australia 3173
Steranoceras sp with Bullamorphites sp, Jurassic, Dogger Formation, Morocco. Largest shell 6 inches. $350.
Sahara Overland Web:Sahara Overland Tel: 011.212.762.6151 Fax: 011.212.129.1516 63 Lotissement Beethoven, Rue Oum Rabiaa, Harhoura / Temara
Australiceras sp, 12 inches, $3000.
Saint-Petersburg Paleontological Laboratory Web:Saint-Petersburg Paleontological Laboratory Tel: 7.812.9676974
For another report on fossils at Tucson 2000, check out fossil collector and fellow Tucsonian Rik Hill's online report at Rik Hill's Scenes from the Tucson 2000 Fossil Show.