Welcome Sign-In | Register
Sold for: Sign-in or Join (free & quick)
includes Buyer's Premium (BP) 


Tylosaurus kansasensis
Late Cretaceous
Smoky Hill Chalk, Niobrara Formation, Logan
Co., Western Kansas, USA
Undisputed Emperors of the high Cretaceous seas, the Mosasauridae were a family of serpentine marine reptiles, apex predators, and scourge of the many and varied ocean-dwelling creatures with which they shared the ancient waters. With a heavy, barrel-shaped body and long propulsive tail, it outlasted all rivals. The family was named for the river Meuse, near Maastricht in the Netherlands, where remains of this astonishing creature were first discovered in the late eighteenth century. Over seventy different species have been discovered around the world, however, in Antarctica, Australasia, Europe, Africa, and the Americas from north to south, ranging from 7 feet in length, to the monstrous 55-foot long Mosasaurus hoffmanni of the late Cretaceous Niobrara chalk in Kansas. This is an outstanding example of a Tylosaurus skull, perfectly preserved with superlative, fine-grained bone texture and a wonderful woody patination. It boasts a near-complete set of the robust and extremely effective-looking, recurvate teeth, with a lovely dark brown enamel. These are backed up by the curious secondary array of pterygoid (flanged) teeth on the palate. The Mosasaur had a soft skull and a jaw that could unhinge, and probably swallowed its prey whole. The still-living food would have been greatly hindered from escaping from the deadly creature's mouth by this nasty surprise waiting inside. Such jaws and dentition are a distinctive feature of Snakes, suggesting to Edward Drinker Cope that Snakes and Mosasaurs may have shared a common ancestor (in fact, they are most similar to the modern Monitor lizards). A museum-standard and highly evocative specimen, the skull measures 47 inches long, presented on an ebonized metal display stand, 23½ inches high.

Condition Report*:

Condition report available upon request.

*Heritage Auctions strives to provide as much information as possible but encourages in-person inspection by bidders. Statements regarding the condition of objects are only for general guidance and should not be relied upon as complete statements of fact, and do not constitute a representation, warranty or assumption of liability by Heritage. Please note that we do not de-frame lots estimated at $1,000 or less and may not be able to provide additional details for lots valued under $500. All lots are sold "AS IS" under the Terms & Conditions of Auction.

Fees, Shipping, and Handling Description: Requires 3rd Party Shipping (view shipping information)

Sales Tax information  |  Terms and Conditions

Bidding Guidelines and Bid Increments

Glossary of Terms

Auction Info

Auction Dates
May, 2012
20th Sunday
Bids + Registered Phone Bidders: 2
Lot Tracking Activity: N/A
Page Views: 3,377

Buyer's Premium per Lot:
25% on the first $50,000 (minimum $14), plus 20% of any amount between $50,000 and $1,000,000, plus 12% of any amount over $1,000,000 per lot.

Heritage membership

Join Now - It's Free

  1. Past Auction Values (prices, photos, full descriptions, etc.)
  2. Bid online
  3. Free Collector newsletter
  4. Want List with instant e-mail notifications
  5. Reduced auction commissions when you resell your
Consign now
  • Cash Advances
  • More Bidders
  • Trusted Experts
  • Over 200,000 Satisfied Consignors Since 1976
Consign to the 2017 May 3 Photographs Signature Auction - Dallas.

Learn about consigning with us

I know for a fact that the sale by Heritage was way beyond what I was offered by other people. If I had to do it over again, I would absolutely choose Heritage again.
Charles Ruffing Jr,
Phoenixville, PA
View More Testimonials receives more traffic than any other auction house website. (Source:

Video tutorial

Getting the most out of search

Recent auctions

2016 April 26  Illustration Art Signature Auction - Dallas
2016 April 26 Illustration Art Signature Auction - Dallas
REALIZED $1,693,612

© 2016 Heritage Auctions | All Rights Reserved