systematics based on siphuncular structure and the position of muscle scars.
All modern cephalopods are carnivorous predators or scavengers, and before big fish evolved, nautiloids
(nautilus relatives) would have been among the major predators in the seas--some nautiloid
shells from the Ordovician period measured up to three metres in length.
On the other hand, Jennifer Nouri was wowed to learn that a smooth black rock with a stunning white imprint - originally found in Morocco - turns out to be a 400 million-year-old orthocone nautiloid
orientations in Arenig and Llanvirn limestones of Oland, Sweden.
The fossils being referred to are orthocone nautiloids
, Rayonnoceras sp., that occur in the top ten feet or so of the Whitmore Wash Member of the Redwall Limestone in Nautiloid
Canyon and elsewhere in the Grand Canyon region (Fig.
-- Two nautiloid
species, Cimomia ozani new species and Eutrephoceras dekayi (Morton), are described from the Campanian Ozan Formation of the Taylor Group in northeast Texas.
Apart from Dawsonoceras and the Silurian coiled-shell nautiloid
Peismoceras Hyatt, no shell colouration was documented in any other species with highly elaborated sculpture.
A very peculiar specimen of a nautiloid
phragmocone was found close to the root-bearing surface (Figs 1B, 2E).
Ordovician and Silurian nautiloid
cephalopods from Anticosti Island: traject across the Ordovician-Silurian (O-S) mass extinction boundary.
Noteworthy is the occurrence of nautiloid
conchs and specific echinoderm columnals (Fig.
At Early Paleocene the transgression of sea emerged which deposited the Sangiali Group like carbonate shallow marine limestone and shale (fossil bearing like bivalves nautiloids
and gastropods) of Sangiali Formation deltaic siliciclastic Rakhi Gaj Formation and coral reef deposits of Dungan Limestone.
Shell organic inclusions have also been used to make dietary comparisons between modern and fossil nautiloids
(Kashiyama et al.