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Brachiosaurus Wasn’t Fuzzy
True to Life?

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Species: altithorax
Range: Late Jurassic (Tithonian, 150-145 MYA) from Utah, Wyoming, Colorado, and Oklahoma
Size estimate: 85 ft length, 62 tons
Discovery: Elmer Riggs, 1903
Classification: dinosauria, saurischia, sauropoda, macronaria, brachiosauridae

Brachiosaurus Wasn’t Fuzzy

You might have noticed the spikes lining the back and hips of this Brachiosaurus sculpture. To a degree, they might resemble pictures you may have seen on the internet which add fuzz at random to dinosaurs. That’s not what these spikes represent. The only skin impressions we have for Brachiosaurus come from footprints, and they suggest it had small, spiky scales on its feet, sort of like mini soccer cleats. Scale impressions from other sauropods usually preserve a mosaic of large hexagonal scales. ­Diplodocus May have grown a loosely Iguana-like fringe of scales, probably along its dorsal ridge. Nothing supports fuzz on sauropods.

What are these spikes doing here? They play only a practical role. Seagulls and other birds were fond of perching on this Brachiosaurus sculpture’s back. When we refreshed the paint job, we added the spikes to prevent them from perching up there and covering the new paint up with a “paint job” of their own. The paint on the fuzz is intended to make them seem as invisible as possible—hopefully you have to squint to see them!

True to Life?

Since no one has ever seen a living dinosaur, and the missing pieces of the fossil record withhold important clues to their appearance, no artistic representation of a dinosaur ever gets it 100% right. On top of that, new discoveries can change our ideas of extinct creatures drastically. So, how close does this sculpture come to what we know of the original animal?

• Over the course of 120 years of study and artistic representation of this popular taxon, a little historical review will set up some helpful context. Elmer Riggs first described Brachiosaurus altithorax in 1903 based on a partial skeleton lacking its skull, as so often happens with sauropods. At the time, it ranked as the largest dinosaur yet discovered and would hold that title for decades more—explaining its popularity in part. Eleven years later, a German expedition to Tanzania uncovered bones they described as a new species of Brachiosaurus which they dubbed brancai. Since the Tanzanian specimens rendered a more complete image of the species’ skeleton and included a well-preserved skull, “Brachiosaurus” brancai became the visual model for scientists and artists alike in representing the genus. In 1988, taxonomic maverick Greg Paul argued for placing the Tanzanian species in its own sub-genus, which he termed “Giraffatitan.” Though no authors since then have followed Paul’s convention of the Giraffatitan sub-genus, due to significant proportional differences between the two species, starting in 2009  more and more scientists are now setting the Tanzanian species within the genus Giraffatitan. The sculpture presented here conforms to the tradition of using the African brancai species as a model for the North American altithorax species and should be taken with the proverbial grain of salt.
• By the way, if this historical background has you wondering whether the Dinosaur Park will follow suit and rename this sculpture a Giraffatitan, know that we have no plans to do so. As artistic representations, the Park’s sculptures do not always need to conform precisely to scientific models (though we make every effort to do so, especially with our newest sculptures). Updating the sculptures as frequently as the science changes simply defies practicality. More importantly—and forming the main motive in this case—we prefer to use the outdated sculptures as records of scientific ideas of the past and may even purposely include outdated depictions among our newer additions for this very reason. The ‘raptors Deinonychus and Utahraptor both exemplify this policy even more obviously. In other words, continuing to call this statue Brachiosaurus frames the opportunity to talk about this taxon’s history more easily than the alternatives. On the other hand, we have a cast/sculpture of the Tanzanian skull, and since it represents an actual specimen rather than the artistic concept of a whole species, we refer to it as Giraffatitan. All that said, if future plans support the creation of a new, more anatomically accurate Brachiosaurus model here at the Park, we would consider renaming this sculpture a Giraffatitan.
• Getting down to the details, then: naturally, the head takes Giraffatitan as its model since we haven’t found a Brachiosaurus skull yet. Or rather, we haven’t found a skull we can confirm belongs to Brachiosaurus. A somewhat isolated skull recovered by one of Othniel Marsh’s expeditions 20 years before Riggs named Brachiosaurus may belong to it. The skull appears longer and lower than Giraffatitan’s long skull, and the scientists who described it noted that it shares some features with both Camarasaurus and Giraffatitan. Overall, though, in terms of general shape it does better resemble Giraffatitan’s tall, crested skull than Camarasaurus’ boxy skull. Either way, the head of this sculpture probably approximates Brachiosaurus’ life appearance fairly well, but not exactly.
• Thanks to a behavioral hypothesis popular during the 1920s, sauropod nostrils traditionally show up on the top of the head in older art, ostensibly for snorkeling purposes. Subsequent studies have shown such a habit would be physically impossible. Further studies have shown that the soft tissue nostrils almost always occupy the lower part of the bony narial opening, as shown on this sculpture.
• Where are this guy’s ears?! If you look carefully, you might see tiny holes behind the skull on this sculpture. Though their location is more or less in the right spot, the apertures should be much larger—closer to half the back of the skull. Again, such soft tissues don’t fossilize, so we don’t know exactly what dinosaur ears would look like, but comparisons with dinosaurs’ living relatives, birds and crocodiles, favor such a model. Oh, and the enormous cartilage structures mammals employ definitely don’t apply to dinosaurs; reptiles lack the evolutionary toolkit that allowed mammals to grow elaborate and adjustable ear structures. No bunny ears on Brachiosaurus!
• Scientists don’t know what soft tissues surrounded the mouth, whether they were beak-like or like lizard lips. Regardless of what soft tissue model we use, the skulls of other sauropods argue against the overbite seen here, at least to this degree.
• One of the important differences between Brachiosaurus and Giraffatitan lies in the proportions of their torsos. Brachiosaurus’ torso grew longer than that of Giraffatitan’s, making it appear longer and lower, with shorter legs, even in individuals that would have similar limb proportions. This sculpture naturally favors the Giraffatitan proportions a little more closely. Brachiosaurus would also appear more barrel-chested in width. The excellent Museum of Ancient Life in Lehi, Utah, features a Brachiosaurus skeletal mount that, like this sculpture, guests can walk under—if you pay them a visit, you’ll find their skeleton is noticeably broader across the rib cage than this sculpture is.
• “Sauropod,” meaning “lizard foot,” refers to the fact that these animals retained five bony fingers and toes on each foot, unlike most dinosaurs. That doesn’t mean they would show up in the living animal, and fossil trackways confirm that some sauropod toes were completely embedded in flesh. Unfortunately, due to sauropods’ typically large sizes, artists often draw from elephants as inspiration, giving their sauropod subjects elephantine feet. This sculpture mostly bucks that trend. Its hind feet correctly portray three large claws and hide the remaining two toes behind a layer of skin. Its hands likewise show the proper thumb claw, and while the sculpt itself suggests two more claws, the paint job mostly mitigates this oversight. Brachiosaurus’ hands lost their phalanges in favor of forming into circular columns that rested directly on the knuckles; the thumb claw probably offered extra traction for steering. Some of Brachiosaurus’ later relatives even ditched the thumb claw entirely. Check out the Moabosaurus and Camarasaurus hind leg mounts in the Stewart Museum for a better picture of general sauropod skeletal anatomy for the feet and hands.
• Sadly, this sculpture also follows the elephantization trope so common in dinosaur art when it comes to its skin. Reptiles don’t typically wear the saggy skin elephants bear—even when they have wattles of some sort, like those on iguanas, the skin’s looseness doesn’t translate across the entire animal. Were this sculpture’s skin more anatomically accurate (at least based on Brachiosaurus’ relatives—see “Brachiosaurus wasn’t fuzzy” on this page for more detail), it would bear a mosaic of scales over skin formed into larger bumps. Wrinkly skin would be limited to immediately around the shoulders and hips.
• Yes, the color is inspired by giraffes. No, we don’t know or have any evidence clarifying how correct or false this interpretation may be, although a recent study apparently recovered a type of skin chemical from a Diplodocus skin sample that supports a color range of browns, tans, even oranges and yellows. This sculpture’s current color scheme is probably more plausible than some it has had in the past.
• Behind the Scenes: for many years, this poor Brachiosaurus sculpture had eyes in its nose. The error probably happened during the process of making the full-sized sculpture, since the small-scale maquette used as a template has its eyes in the right place. Sculptors for the full-size statue may have used a picture of the skull as a reference and misidentified which opening would have been the eye socket; like elephants, Giraffatitan and some other sauropod skulls have such prominent noses that the eyes become easy to overlook. In 2019, artists Kirk Larsen and J. Cotton gave the Brachiosaurus a facelift and fixed some of those errors, as well as giving it newer, more lifelike eyes.
• Behind the Scenes: we often have to check this sculpture’s armpits for wildlife like wasps or even bats. If ever you see an animal hanging from this sculpture, please alert Park staff—DO NOT ATTEMPT TO INTERACT WITH IT YOURSELF. Whether pterosaurs or other airborne animals hung off of a live Brachiosaurus, science can’t determine that, but considering how often birds, insects, and even bats hitch rides on large mammals, it’s not implausible.
• Behind the Scenes: unlike most of the other sculptures in the Park, this Brachiosaurus is designed and reinforced specifically for guest interaction. Please enjoy the photo op of fitting an entire group of humans under its belly. You can even check to see if it’s ticklish . . . though if you get stomped on as a result of such an experiment, that’s on you! We do not recommend climbing it.