On January 15, the American Museum of Natural History unveiled the first new fossil mount to be added to their paleontology halls in 20 years. It is the reconstructed skeleton of an as-yet-unnamed titanosaur, an immense sauropod dinosaur that lived in Argentina during the mid-Cretaceous. The titanosaur is probably the most hyped-up fossil mount since Sue, at least in the United States (Sophie the Stegosaurus in the U.K. and Tristan the Tyrannosaurus in Germany received similar attention). This merits some discussion. The AMNH public relations staff pulled no punches in selling the titanosaur as a must-see exhibit. Huge advertisements appeared on buses and buildings around New York, including in Times Square. The legendary David Attenborough hosted a television special on the discovery of the fossils. Countless local and national news outlets were invited to the titanosaur’s unveiling earlier this year. But is this dinosaur really the find of the century?
It depends. The titanosaur represents a species new to science, but it has not yet been formally published. The fossils were recovered in 2014 by José Luis Carballido and Diego Pol, paleontologists with the Egidio Feruglio Paleontology Museum (the AMNH connection is that Pol was a doctoral student of Paleontology Division Chair Mark Norell). Bones from at least six individuals of the same species were found, together representing 70% of the skeleton. However, AMNH staff have mostly avoided calling this animal the biggest dinosaur ever.
Indeed, declaring any dinosaur species to be the largest is a fool’s errand. We’ve known for some time that South American titanosaurs, as a group, are probably the biggest land animals that ever lived. Unfortunately, these giants are typically represented by only a few isolated bones. For an animal to become fossilized, it needs to be buried shortly after death. But it takes a lot more dirt to cover a large animal than a small one. A flood or landslide big enough to completely cover a sauropod over a hundred feet long would be an exceedingly rare event. More often, these animals were picked apart by scavengers for some time before a few of the more durable bones were buried and fossilized. For example, Argentinosaurus is known from about ten percent of the skeleton, and Puertasaurus is known from just four vertebrae. Paleontologists can use better-known relatives to produce reasonable reconstructions from even these limited remains, but any length estimate is a ballpark figure. Even among related animals, proportions can vary significantly. Consider, for example, the very long tail of a green iguana as compared to the stubby tail of a Galapagos land iguana. Carballido and Pol’s find stands out among other titanosaurs because two-thirds of the skeleton is known. hen the description is published, it will undoubtedly shed new light on the skeletal anatomy of this group. Still, the missing parts mostly come from the neck and tail, which will probably preclude a precise estimate of the animal’s total length.
*This level of completeness is not entirely unprecedented. Dreadnoughtus, described in 2014, is also about 70% complete.
We can’t say the AMNH titanosaur is absolutely the biggest known dinosaur, but what about the mount? At 122 feet, the reconstructed skeleton prepared by Research Casting International dwarfs AMNH’s resident sauropod, the 82-foot apatosaurine. It’s also a fair bit longer than the museum’s brain-breakingly huge blue whale model. AMNH is not the first museum to display a titanosaur, however. The Royal Ontario Museum has a 110-foot Futalognkosaurus, which the AMNH mount handily beats. But the new titanosaur is essentially the same size as the 123-foot Argentinosaurus at the Fernbank Museum of Natural History (duplicates also exist in Europe and South America). The difference, as mentioned, is that not a lot about Argentinosaurus is actually known, and the mount is almost entirely a sculpted reconstruction. By comparison, the AMNH titanosaur is largely composed of 3-D printed components based on scans of original fossils. “The biggest reconstructed skeleton of a reasonably well-known dinosaur” isn’t the catchiest headline, though.
Suffice it so say that on paper, the AMNH titanosaur isn’t a revolution for dinosaur science. When I went to see it last weekend, I expected to see a typical example of a well-studied group of dinosaurs. I was not prepared.
This bastard is BIG. I could go through a whole series of superlatives, but it’s impossible to describe the experience of sharing space with this magnificent skeleton. You cannot comprehend what a 122-foot dinosaur really is until you’ve experienced it. It helps that the titanosaur occupies a smallish, low-ceilinged room (a century ago, this was the infamous Hall of the Age of Man). It also helps that there are no long lines of sight into this space. You turn a corner and you are quite abruptly in the titanosaur’s presence. Regardless, the marketing line that was ubiquitous earlier this year – “everything else got a whole lot smaller” – rings unsettlingly true. Compared to the titanosaur, the mammoth and mastodon across the hall look like pipsqueaks. Even the AMNH blue whale, which usually requires a double-take, became a little easier to take in.
I’m no stranger to sauropods. I teach people about them at work all the time. But seeing the titanosaur in person was a revelation, and something I strongly recommend to anyone interested in the natural world. The titanosaur may not be the most important dinosaur discovery of our generation, but by giving it corporeal presence, AMNH created an incredible symbol. This is life at its limits, an embodiment of the incredible things the tetrapod body plan can do.
P.S.: If you’re concerned about the fate of the juvenile Barosaurus model that used to occupy this space, worry not. It now lives at the Cleveland Museum of Natural History, and will be on display at least through October of this year.