Class Cephalopoda, Subclass Ammonoidea, Order Ammonitida, Superfamily
fossil is 3 ¾” high on a 2 ¼ x 1” base
Heteromorph ammonites are among the most fascinating of all invertebrate-shelled
cephalopod fossils. Hyphantoceras reussianum are considered uncommon,
and generally limited in distribution to European collectors.
Few find their way to the USA. My German dealer associate recently
sent this one to me as part of a large exchange. It is very well
preserved, featuring a number of twists, turns and angles. Mounted
on a small flat-lying matrix base, it is visually and aesthetically
stunning. A truly wonderful example of nature’s artistry.
was a diverse group of heteromorph ammonites found throughout
the oceans of the world during the
The nostoceratids are famous for the bizarre coiling of their shells.
The ecology of nostoceratids is the subject of continued speculation,
as the bizarrely coiled shells have no streamlining, strongly suggesting
that the living animals had extraordinarily poor swimming ability,
if any ability at all. As such, experts and ammonite enthusiasts
presume that the nostoceratids either floated passively in the
water column, or were bottom-dwellers that may or may not have
crawled on the seafloor. The nostoceratids, as with all other Cretaceous
ammonites, perished during the Cretaceous–Tertiary extinction