Reviews
This Specimen has been sold.
HERE ARE SOME OTHER SIMILAR FOSSILS FOR SALE
3" Iridescent Hoploscaphites Ammonite Pair - South Dakota
This is a pair of Hoploscaphities ammonites collected from the Fox Hills Formation of South Dakota. These ammonites are in excellent condition, considering the difficulty (and time required) to remove them from the rock. The shells have a flashy iridescence that enhances the natural texture and coloring. The larger of the two is believed to be a female and the smaller is a male.
It comes with an acrylic display stand.
It comes with an acrylic display stand.
About These Ammonites
These 70-million-year-old Cretaceous ammonite fossils come from a time when South Dakota was submerged beneath the Western Interior Seaway, a warm, shallow inland ocean that once stretched from the Arctic to the Gulf of Mexico. Ammonites were extinct marine cephalopods related to modern squid, octopus, and cuttlefish, but unlike their soft-bodied relatives, they lived inside coiled, chambered shells. As the animal grew, it added new chambers, using them to regulate buoyancy and move efficiently through the ancient seas. Their abundance and rapid evolution make ammonites some of the most important index fossils for dating marine rocks.
After death, these ammonites settled into seafloor sediments where mineral-rich waters slowly formed concretions around the shells, protecting them from crushing and decay for tens of millions of years. When these stone nodules are split open today, the fossils are revealed locked inside and must be carefully hand-prepared to remove the surrounding rock. This delicate, time-consuming process—often done with air scribes and fine tools—can take many hours per specimen, gradually exposing the shell’s ribs, sutures, and natural curvature. The finished fossils are striking remnants of South Dakota’s ancient ocean, preserving a moment from a world that vanished long before dinosaurs walked on land.
These 70-million-year-old Cretaceous ammonite fossils come from a time when South Dakota was submerged beneath the Western Interior Seaway, a warm, shallow inland ocean that once stretched from the Arctic to the Gulf of Mexico. Ammonites were extinct marine cephalopods related to modern squid, octopus, and cuttlefish, but unlike their soft-bodied relatives, they lived inside coiled, chambered shells. As the animal grew, it added new chambers, using them to regulate buoyancy and move efficiently through the ancient seas. Their abundance and rapid evolution make ammonites some of the most important index fossils for dating marine rocks.
After death, these ammonites settled into seafloor sediments where mineral-rich waters slowly formed concretions around the shells, protecting them from crushing and decay for tens of millions of years. When these stone nodules are split open today, the fossils are revealed locked inside and must be carefully hand-prepared to remove the surrounding rock. This delicate, time-consuming process—often done with air scribes and fine tools—can take many hours per specimen, gradually exposing the shell’s ribs, sutures, and natural curvature. The finished fossils are striking remnants of South Dakota’s ancient ocean, preserving a moment from a world that vanished long before dinosaurs walked on land.
SPECIES
Hoploscaphities nicoletti
LOCATION
South Dakota
FORMATION
Fox Hills Formation - Trail City Member - Hoploscaphites nicolletti Zone
SIZE
Larger Ammonite: 2.55" wide, Entire specimen: 3 x 2.55"
CATEGORY
SUB CATEGORY
ITEM
#209700
We guarantee the authenticity of all of our specimens.
