If you don’t have $30 million to bid on “Gus” – a 67 million-year-old Tyrannosaurus rex skeleton to be auctioned at Sotheby’s on July 14 – you can have a late Cretaceous jewel for relative peanuts: a T.-rex tooth for a mere $40,000 to $60,000.

The tooth displayed in a vitrine next to the hostess stand is part of the fun at Sotheby’s hot-button restaurant, Marcel. It’s one of dozens of precious objects and works of art displayed amidst the clubby but open-to-all French eatery’s mohair-upholstered booths, walnut-paneled walls, and original metal lamps designed by the landmark building’s architect, Marcel Breuer.

The art displays are a bold marketing stroke at Sotheby’s, the world’s largest auction house with over $5 billion in annual sales at locations around the world. Most of the works in Marcel’s dining room, bar and adjacent areas — such as an Ellsworth Kelly abstract composition in blue, black and green at the top of the stairs — are for sale at auction. (The few that aren’t are on loan from private collections).

The works are chosen by “a curatorial  committee in our private sales division,” explained Lisa Dennison, chairman of Sotheby’s North and South America.

“Their responsibility is to work with Marcel so there’s something interesting on display at all times,” she said.

A QR code fills diners in on the treasures on view.  One recent batch included untitled abstract paintings by Franz Kline and Willem de Kooning, sculptures by John Chamberlain, a Renoir nude and a Robert Indiana aluminum “Love” sculpture.

“Marcel fits with their strategy. They’re in the business of selling not only art, but luxury items and even a dinosaur,” said Art historian Mari-Claudia Jimenez, a former Sotheby’s president and now an advisor to the institution.

“The displays give you a sense of how you might live with a dinosaur tooth or a Robert Indiana sculpture or the Joan Mitchell painting over the entire dining room,” Jimenez added.

Of course, Marcel is first and foremost a restaurant, and chef-co-owner Marie-Aude Rose’s  classic dishes have thrilled guests since the opening last month. Her menu is attuned to well-traveled local taste.

Rose, who also co-owns La Mercerie downtown, didn’t worry about competing with the setting or  the masterpieces on view. 

“You go to Paris and there are amazing restaurants in settings surrounded by art,” she said.

“Our neighbors here are used to traditional French. I wanted to make Marcel a place they could come back to,” she added. 

The most popular dishes include endive salad, beef tartar and Dover sole meunière

But the ones we’ve ordered more than once were Hungarian-style chicken strongly seasoned with paprika and Provençal-influenced orecchiette pasta with basil, tomato and olive oil — eclectic, bold dishes that complement the venue’s beauty.

The dining room and a sunken outdoor garden are the vision of designer Robin Alesch, who with her husband Stephen Alesch own architectural firm Roma and Williams, which is a partner in the restaurant with Sotheby’s.

“We wanted it to reflect the taste of the building. It wasn’t going to be an English pub,” she laughed,” Dennison said with a laugh.

Bronze, stone and wood — materials in synch with Breuer’s Brutalist design — frame  a white-tablecloth setting  “like a private club, but a very democratic one that’s open to everyone,” Jimenez said.

Our wide-eyed spies said “everyone” has included Michael Bloomberg, Woody Allen and his estranged journalist son Ronan Farrow (on the same night!), Sofia Coppola, Jodie Foster, Chloe Sevigny, Miuccia Prada, and a horde of real estate moguls — but mostly, food lovers from the neighborhood.

How much the Marcel displays add to an art work’s value is hard to quantify. Jimenez recalled that a painting by Russian expressionist Alexej von Jawlensky was “originally estimated at $150,000 to $200,000 and sold for $256,000.”

But Stephen Alesch said it was too early to tell. “We’re just starting out,” he said.