Fossil Ammonite with Mosasaur Vertebrae in Rock - Asfla, Morocco

This is a 7.3 x 7.1" specimen featuring a complete Choffaticeras segne ammonite and two mosasaur vertebrae, one of which appears to be a cervical vertebra from Tethysaurus nopcsai. It's tough to tell the species for sure, as isolated mosasaur vertebrae can be tough to accurately identify.

The ammonite measures 4.9" wide and the ccervical vertebra is 2.2" wide. It comes from the Upper Cretaceous deposits near Asfla, Morocco. One edge of the rock has been cut flat for vertical presentation.

About Ammonites

Ammonites were ancient marine cephalopods, similar to today's squids and octopuses, but with a defining feature: their distinctive, tightly coiled spiral shells. These shells, resembling those of modern nautiluses, served as both a protective home and a buoyancy aid, allowing ammonites to navigate the prehistoric seas with ease. First emerging around 240 million years ago in the Triassic Period, ammonites thrived for over 175 million years, adapting through numerous forms and sizes. As predatory creatures, they likely fed on smaller marine organisms, using their tentacles to capture prey. However, their long reign came to an end 65 million years ago at the close of the Cretaceous, coinciding with the mass extinction event that also eliminated the dinosaurs.


About Mosasaurs

Mosasaurs were large, carnivorous marine reptiles that lived during the Late Cretaceous Period, approximately 90 to 66 million years ago. Though often mistaken for dinosaurs, they were actually more closely related to modern monitor lizards, including the Komodo dragon. Over time, their ancestors transitioned from land to sea, evolving paddle-like flippers, streamlined bodies, and powerful tails that made them highly efficient swimmers. Some species developed crescent-shaped, shark-like tail fins that allowed for strong, sustained propulsion through open water. Sizes varied widely, with many species measuring 20 to 30 feet long, while the largest—such as Mosasaurus hoffmannii—may have exceeded 50 feet in length.

As apex predators, mosasaurs occupied the top of the marine food chain. Their long jaws were lined with sharp, conical teeth ideal for gripping slippery prey, and fossil evidence shows they fed on fish, sharks, ammonites, seabirds, and even other mosasaurs. Despite their fully aquatic lifestyle, mosasaurs were air-breathing reptiles and had to surface regularly, much like modern whales. They thrived in oceans around the world until the Cretaceous–Paleogene extinction event 66 million years ago, which wiped out the dinosaurs and many marine reptiles, bringing the age of mosasaurs to an end.

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DETAILS
SPECIES
Choffaticeras segne & Tethysaurus nopcsai?
LOCATION
Asfla, Goulmima, Morocco
SIZE
Entire Piece: 7.3 x 7.1"
CATEGORY
SUB CATEGORY
ITEM
#334637
GUARANTEE
We guarantee the authenticity of all of our specimens.