This virtual collection was last curated by Jonathan Hendricks on August 12, 2022. 
Each model is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Unless otherwise indicated, each model was created by Emily Hauf using specimens at the Paleontological Research Institution, Ithaca, New York.
An associated section about the Subclass Ammonoidea is now available on the Digital Encyclopedia of Ancient Life.
Order Agoniatitida
Holotype of the cephalopod Agoniatites intermedius (PRI 5370); from the Devonian Cherry Valley Limestone of Cayuga County, New York. Specimen from the collections of the Paleontological Research Institution, Ithaca, New York.
Fossil ammonoid Manticoceras sinuosum from the Devonian Cashaqua Formation of Yates County, New York (PRI 49803). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Longest dimension of specimen is approximately 6 cm. Model by Neil Pezzoni.
Order Goniatitida
Fossil specimen of the goniatite ammonoid Agathiceras ciscoense from the Pennsylvanian Wayland Shale of Brown County, Texas (PRI 76762). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York.
Fossil specimen of the goniatite ammonoid Imitoceras rotatorium from the Mississippian of Floyd County, Iowa (PRI 44566). Specimen is on display at the Museum of the Earth, Ithaca, New York. Maximum diameter of specimen is approximately 8.5 cm.
Fossil specimen of the cephalopod Tornoceras uniangulare from the Devonian Geneseo Shale of Tomkins County, New York (PRI 55004). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Maximum diameter of specimen is approximately 6 cm.
Order Prolecanitida
Fossil specimen of the ammonoid cephalopod Medlicottia intermedia from the Permian of Kazakhstan (PRI 70568). From the collections of the Paleontological Research Institution, Ithaca, New York. Maximum diameter of specimen is approximately 4.5 cm.
Order Ceratitida
Fossil specimen of the ceratite ammonoid Gymnotoceras beachi from the Triassic Toad Formation of British Columbia (PRI 43629). Specimen is from the collections of the Paleontological Research Institution. Maximum diameter is approximately 4.5 cm.
Order Ammonitida
Planispiral ammonites
Fossil specimen of the ammonoid cephalopod Cleoniceras besairiei from the Cretaceous period. Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Maximum diameter of specimen is approximately 12 cm.
Fossil specimen of the ammonite cephalopod Perisphinctes from the Jurassic period. Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Maximum diameter of specimen is approximately 7.5 cm.
Fossil specimen of the ammonite cephalopod Dactylioceras commune from the Jurassic of Dorset, England (PRI 76785). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Maximum diameter of specimen is approximately 4.5 cm.
Fossil specimen of the ammonoite Teloceras sp. from the Jurassic of Calvados, France (PRI 76759). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Maximum diameter of specimen is approximately 4.5 cm.
Fossil specimen of the ammonite Oppelia subradiata from the Jurassic Interior Oolite of de Bayeux, France. Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Maximum diameter of specimen is approximately 10 cm.
Fossil specimen of the ammonoid cephalopod Gunnarites sp. from the Cretaceous Lopez de Bertodano Formation of Snow Hill Island, Antarctica (PRI 61543). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Diameter of specimen (not including surrounding rock) is approximately 9 cm.
Fossil specimen of the ammonoid cephalopod Engonoceras pierdenale from the Cretaceous Comanche Peak Limestone of Texas (PRI 76761). From the collection of the Paleontological Research Institution, Ithaca, New York. Maximum diameter of specimen is approximately 16 cm.
Fossil specimen of the ammonoid cephalopod Cadoceras sublaeve from the Jurassic (Callovian) of Gloucestershire, England (PRI 70580). Specimen is from the collections of the Paleontological Research Institution. Largest dimension is about 5.5 cm.
Fossil specimens of the ammonite cephalopod Maorites sp. from the Cretaceous Lopez de Bertodano Formation of Seymour Island, Antarctica (PRI 61273). Specimen is from the research collections of the Paleontological Research Institution, Ithaca, New York. Longest dimension of rock is approximately 17.5 cm.
Fossil shell of the ammonite Grossouvrites sp. from the Cretaceous Lopez de Bertodano Formation of Seymour Island, Antarctica. Specimen is from the research collection of the Paleontological Research Institution, Ithaca, New York. Maximum diameter of specimen is approximately 25 cm.
Fossil internal mold (or, steinkern) of a chamber of the ammonite Grossouvrites sp. from the Cretaceous Lopez de Bertodano Fm. of Seymour Island, Antarctica (PRI 61185). Specimen is from the research collections of the Paleontological Research Institution, Ithaca, New York. Longest dimension of specimen is approximately 8.5 cm.
Fossil ammonoid Asteroceras obtusum from the Jurassic of England (PRI 43873); specimen exhibits ammonite sutures. Specimen is on display at the Museum of the Earth, Ithaca, New York. Maximum diameter of specimen is approximately 8.5 cm.
Fossil ammonoid Sagenites shastensis from the Triassic Hosselkus Limestone of Shasta County, California. Specimen is on display at the Museum of the Earth, Ithaca, New York. Maximum diameter of shell is approximately 5 cm.
Fossil ammonoid cephalopod Discotropites lineatus from the Triassic Hosselkus Limestone of Shasta County, California. Specimen is on display at the Museum of the Earth, Ithaca, New York. Maximum diameter of shell is approximately 6 cm.
Heteromorph (irregular) ammonites
Fossil specimen of the ammonite cephalopod Hoploscaphites nebrascensis from the Cretaceous Fox Hills Formation of South Dakota (PRI 76775). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Longest dimension of specimen is approximately 8.5 cm.
Fossil ammonoid Scaphites warreni from the Cretaceous Mancos Shale of Utah (PRI 44578). Specimen is on display at the Museum of the Earth, Ithaca, New York. Longest dimension of specimen is approximately 6 cm.
Fossil specimen of the heteromorph ammonite Hypoturrilites gravesianus from the Cretaceous of Kent, England (PRI 76777). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Length of specimen is approximately 10.5 cm.
Fossil specimen of the heteromorph ammonoid Diplomoceras maximum, on display at the Museum of the Earth in Ithaca, New York (PRI 13889). This specimen was discovered by Dr. William Zinsmeister and Dr. Anton Oleinik in Cretaceous-aged rocks on Seymour Island, Antarctica. The complete length of this twisted ammonoid’s shell is approximately 4 meters.
Fossil specimen (fragment) of the large heteromorph ammonite Diplomoceras sp. from the Cretaceous Lopez de Bertodano Formation of Seymour Island, Antarctica (PRI 61188). Specimen is from the research collections of the Paleontological Research Institution, Ithaca, New York. Length of specimen is approximately 13 cm
Baculite ammonites
Fossil specimen of the ammonoid cephalopod Baculites compressus from the Cretaceous Pierre Shale of South Dakota (PRI 44571). Specimen from the collections of the Paleontological Research Institution, Ithaca, New York. Specimen is approximately 15.5 cm.
Fossil specimen of the ammonite cephalopod Baculites sp. from the Cretaceous Pierre Shale of Wasta, South Dakota (PRI 70605). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Maximum length of specimen is approximately 8.5 cm.
Fossil specimen (fragment) of the baculite ammonite cephalopod Baculites sp. from the Cretaceous Pierre Shale of Wasta, South Dakota (PRI 70605). Specimen is from the collections of the Paleontological Research Institution, Ithaca, New York. Maximum length of specimen is approximately 7 cm.