Impressive 22" Mosasaur Jaw Section - Superb Preparation

This is a very impressive jaw section of from Prognathodon, a very large type of Mosasaur. It's 22" long, still embedded in it's original matrix and the preparation on it is outstanding.

It's uncommon to find jaw sections with teeth still in place, they are typically remounted or composited during preparation, but not with this specimen. What makes this piece so outstanding, is there is NO COMPOSITING and the only restoration is some of enamel on the second tooth from the left where it had been broken and repaired. There is some stabilization to the back of the matrix. This specimen is in it's natural state, just superbly prepared.

Another interesting feature of this jaw is you can see several of the unerupted, replacement teeth growing inside the jaw. Mosasaur's like dinosaurs and sharks replaced their teeth frequently as they become worn or broken. There were teeth continuously growing inside the jaw bone, underneath and to the side the visible teeth which could move into place when tooth was lost.

If you are looking for a top quality Mosasaur jaw with no compositing and practically no restoration this one is for you. This specimen displays nicely on the included acrylic stand.

Mosasaurs are a family of enormous marine reptiles that truly dominated the seas 90 million years ago. They ruled during the last 20-25 million years of the Cretaceous period. With the extinction of the ichthyosaurs and decline of plesiosaurs, mosasaurs diversified to become prolific apex predators in nearly every habitat of the oceanic world.

Artists reconstruction of the mosasaur Prognathodon saturator.
Artists reconstruction of the mosasaur Prognathodon saturator.

Larger mosasaurs were the great leviathans of their time, extending 10–15m, or 33–49ft long. Hainosaurus holds the record for longest mosasaur, at a seemingly impossible 57ft. The smaller genera were still an impressive 10–20ft long. Mosasaurs probably evolved from semi-aquatic scaled reptiles which were more similar in appearance to modern-day monitor lizards. They had double-hinged jaws and flexible skulls (much like that of a snake) which enabled them to gulp down their prey almost whole.

The gruesome unchewed contents of fossilized mosasaur guts have revealed a varied diet of sea birds, ammonites, smaller marine lizards, possibly shark, and even other mosasaurs. Ammonites were especially crunchy mosasaur treats. They were abundant in the Cretaceous sea, and some Mosasaurs had specialized teeth for the job.

Mosasaurs probably lurked for an ambush, rather than hunt, possibly using their powerful tail flukes for extra thrust to dart out and swallow unsuspecting prey. Non-reflective, keeled scales may have been a great advantage to the Mosasaur sneak-attack.

Mosasaurs breathed air and gave birth to live young. The bronchi leading to the lungs run parallel to each other instead of splitting apart from one another as in monitors and other terrestrial reptiles. They were well-adapted to living in the warm, shallow, epicontinental seas of the period.

Although Mosasaurs diversified and proliferated at a spectacular rate, their specialization is considered the source of their demise when marine systems collapsed at the end of the Cretaceous.
Prognathodon sp.
Oulad Abdoun Basin, Morocco
Phosphate Deposits
Specimen 22" Long, 12.5" Tall, 5" Thick, 17 lbs
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