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Michael Wall, Ph.D.
Director of the Biodiversity Research Center of the Californias

Melli, the Model Guy

By Kerri De Rosier

This is the third article in a series of four about the Museum’s
FOSSIL MYSTERIES exhibition, which opened July 1, 2006.

How do you build a shark from a set of teeth? Need a mural with drawings of creatures that aren’t around anymore? How about a full-scale model of a dinosaur? Meet Jim Melli—artist sculptor, zoologist, exhibit designer, naturalist, model builder, insect guy, live exhibit curator. The list goes on.

Melli, whose title is “exhibition artist,” received a zoology degree from San Diego State University and nearly finished a graduate degree in entomology. He remembers taking one art class—in lithography.

His office, which doubles as his workshop, is a jumble of models, drawings, and even some live specimens in jars. His tools: a set of colored pencils, modeling clay, wire mesh, lots of books, and the desire to know.

For FOSSIL MYSTERIES, Melli did the maquettes for the megalodon shark, ankylosaur, pterosaur, baby mastodon, and the lion on a rock. He also designed the Eocene diorama with incredible detail, right down to the lichen on the trees, and drew sketches that were used as the basis for sculptures produced by the Science Museum of Minnesota.

To make the megalodon model, Melli started with only a set of teeth. How do you get a shark from a set of shark teeth? Melli explained that a paleontologist can look at the teeth and determine the closest relative. “The characteristics of the teeth of different sharks tell us which group they belong to,” said Melli. “Teeth are just about the only parts that are preserved on sharks because they have a skeleton of cartilage. Some of the cartilage can become ossified and you can get vertebra, but for the most part, all that remain are teeth.”

Showing me some sample teeth, Melli said, “This one is related to a tiger shark. It has these serrations and this weird hook shape. The tooth is asymmetrical, whereas this tooth, which is related to the mako shark, is adapted toward grabbing fish and holding onto them.” Michael Gottfried from Michigan State University helped Melli and his team reconstruct the shark. Most shark teeth are scattered in the deposits where they are found, because sharks shed their teeth continuously as they age. Similar to a conveyor belt system, the jaw tissues roll forward, and as the younger teeth mature, the older teeth on the outer part of the “conveyor belt” fall out. Melli and his team used casts of an almost-complete set of fossil teeth found in Florida that belonged to one individual: the teeth were all associated in one bunch (all from different parts of the jaw). In a modern shark, teeth are configured differently depending on where they are in the jaw, so the artists were able to accurately reconstruct the shark’s dental pattern. To determine how big to make the shark, Gottfried used a mathematical formula comparing the size of great white shark teeth to the casts of the fossil teeth. Based on the size of the teeth they used, Gottfried calculated that the shark was about 34 feet long.

Gottfried believes the megalodon probably wasn’t as slender as the great white shark, because the bigger the animals get, the beefier they have to be to support all their weight. Also, to be stable, they had wider pectoral fins relative to the body size and a shorter snout than a white shark. The end result is an educated guess—as many reconstructions are.

According to Melli, “Gottfried has the most knowledge of megalodon. Other reconstructions of megalodons are more like white sharks: they are not as accurate as ours. Ours [is] by far the most accurate fleshed-out reconstruction ever made.”

Artists logged many hours to make the reconstruction realistic. The shark has several rows of offset teeth, coming at different angles. Some jaw reconstructions shown at museums depict one row of teeth perfectly lined up. In addition, the model was proportioned and scanned by computer, and then the foam was hand-carved using all those proportions. Melli described the engineering inside the model as a steel internal structure that supports all the weight: “even though it’s all foam, it’s hollowed out, like Styrofoam cups. It has a urethane/fiberglass resin coating on the outside of it, which is really thick and really stiffens it up.”

Atomic Props, one of the subcontractors working for the Science Museum of Minnesota, constructed the shark. Melli traveled to Minnesota three times to consult on the painting, texture, and color. The rest of the time, he depended on phone conferences and e-mailed pictures. There were a lot of challenges.

“How are you going to get this big fiberglass thing to look like an animal?” said Melli. “Some of those challenges are not only about what it looks like, but what materials to use. We have this waterbased epoxy stuff that’s like putty. We put a layer over the fiberglass, smoothed it all out and got rid of that unnatural, sanded fiberglass look.” This material was also used for sculpting details around the eyes, nasal flaps and mouth.

Another challenge for Melli was getting into the mind of fabricators who are more used to creating 15-foot-tall cups of Starbucks® cappuccino or billboards wrapped in Crown Royal® bags than creating something that’s supposed to look lifelike.

“This is the first animal that they’ve done—an alive, real thing,” said Melli. “They know how to do the engineering to make it big, but their artists are used to making giant bags. When I was there, they were making billboards in four section pieces—they were probably 50 or 60 feet long. When you’re going by at 90 miles an hour in a car at a hundred feet away, they look pretty darn good, but if you walk up to them, they’re crude.” Melli had to impress upon the engineers and artists that at the Museum, scientists are going to scrutinize every aspect of the animal’s design.

The shark hangs from the Museum’s atrium, its wide mouth within striking distance as visitors walk past on the second floor.

Melli figures out his own fossil mysteries In addition to sculptures and dioramas, Melli drew some of the illustrations for the text panels, and provided drawings for what he called “a lot of weird little animals that are unique to San Diego” for artists at Blue Rhino Studios who sculpted the animals. But how does Melli know what the animals looked like? When he needs to uncover his own fossil mystery, he turns to books, the scientists on staff, his own life science knowledge, and his imagination.

Melli described how he created Harpagolestes, what he calls “the pit bull from hell.”

“It’s an ungulate, with hoof-like feet. You can tell by looking at the skeleton that it was like a sheep in wolf ’s clothing. What did that guy look like? Well, we have a jaw and some bones, so we know that he was stocky, and there are other fossils that are more complete of animals in the same group.”

He started with a pencil drawing, then made copies, and then did something that every ten-year-old would love to do for a living: he colored them in using colored pencils. “That’s what the fabricators used as color guides,” said Melli.

Then Melli described a crocodile-like creature you can imagine in a pair of running shoes. “It was terrestrial, and it had long legs and serrated teeth. Fish eaters have teeth that aren’t made for slicing and cutting: they’re more for holding. These guys have serrated teeth for slicing flesh, and they were probably pretty efficient in capturing mammals and things that they fed on. They were probably really quick, and prowled around on land more than modern crocodiles do.”

With the help of Melli and the other museum staff, visitors are able to figure out their own fossil mysteries. For example, Melli explained that the Museum has some jaws that look like something was chewing on them. They were all in the same place and got buried and fossilized. “One of the interactive parts of the exhibition shows the bones and asks: ‘what do you think happened? How did all these jaws get there? Was there a landslide? A big flood, and they got swept to their deaths? Or, did some critter take them to his lair and dine on them?’” asked Melli.

It’s Melli’s hope that visitors will have fun, and learn something at the same time. “We want people to connect with nature—turn them on to nature, and have fun, too.”