Aturia aturi
Phylum Mollusca, Class Cephalopoda, Subclass Nautiloidea, Order Nautilida, Family Aturidae
Geological Time: Lower Eocene
Size: Fossil is 60 mm tall by 80 mm across (maximum)
Fossil Site: Ad Dakla, Morocco
Code: 18037
Price: Sold
 Description:
This fine Nautiloid is an Aturia from the far Western Sahara of Morocco
which is free of matrix. This allows you the opportunity to view this
fine, robust specimen from all aspects. It has been polished to bring
out the fine details. The complex suturing pattern distinguishes these
cephalopods from the ammonites (I have posted it with the ammonites
as they are close relatives). Indeed the suture is one of the most
complex for all Nautiloids. The Nautilida have a rich evolutionary
history which began in the early Devonian. The order suffered a drastic
decline in the late Devonian, only to have an extensive radiation
in the Carboniferous. They suffered less than some other orders at
the end of the Permian, and did better than the ammonites by surviving
the Cretaceous extinction, leaving one descendant, the modern-day
Nautilus. Why did the Nautilida survive the end-Cretaceous catastrophe
while all Ammonites perished? The Ammonites were more restricted in
distribution, and were more often found in shallower environments
than the Nautilida. While there is some evidence that the may have
persisted for some 100,000 years after the meteor stuck, that is the
last of them. The Aturidae held out until the Miocene, while two species
of Nautiloids exist today as deep water inhabitants. |
