| Pachydiscidae
Cenomanian - Maastrichtian | |
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| Eupachydiscus isculensis from Cretaceous – Bergamo (Italy) | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | †Ammonoidea |
| Order: | †Ammonitida |
| Superfamily: | †Desmoceratoidea |
| Family: | †Pachydiscidae Spath 1922 |
| Genera | |
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See text | |
Pachydiscidae is a family of middle and upper Cretaceous ammonites in the superfamily Desmoceratoidea.
Pachydiscidae species are moderate to large in size, evolute to rather involute, and vary in section from inflated and depressed to high-whorled and compressed. They are distinguished from the Desmoceratidae by strong ribbing at some growth stage, that normally crosses the venter uninterrupted, and by the tendency to develop strong tuberculation, at least on the umbilical shoulder.[citation needed]
Pachydischidae evolved from Desmoceratidea, during the Lower Cenomanian, about the same time as the Kossmaticeratidae, but lived further into the Maastrichtian, virtually to the end of the Cretaceous.
Fossils of Pachydiscidae are found in the Cretaceous marine strata throughout the world, including Angola, Antarctica, Armenia, Australia, Austria, Belgium, Brazil, Bulgaria, Chile, Czech Republic, Denmark, France, Germany, Haiti, India, Jamaica, Japan, Mexico, Netherlands, Nigeria, Oman, Russia, South Africa, Spain, Turkey, United States and Uzbekistan.
| Pachydiscidae |
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