Deinocheirus > Spinosaurus

There’s a new giant, sail-backed, piscivorous theropod in town.

Just a month after Ibrahim et al. (2014) revealed their new interpretation of Spinosaurus aegypticus, Lee et al. have done one better: they've published a description of Deinocheirus mirificus, one of the most mysterious dinosaurs ever found. For those not keeping score at home, Deinocheirus was discovered in 1965 during a Polish-Mongolian expedition into the southern Gobi Desert. Unfortunately, all that was found was a pair of enormous arms—indelibly seared into the minds of every man, woman, and child who opened a dinosaur book over the next forty years. It was pretty easy to see that Deinocheirus was an ornithomimid, but it must have been absolutely enormous. It wasn't until 2006 and 2009 that more skeletal material was discovered—both in the field and in a private collection. For more on this, Ed Yong and Brian Switek have fascinating write-ups about the discovery and its history.

It's a duck-billed, hump-backed, horse-headed, slow-moving ominovorous ostrich dinosaur.

I’ll talk about the actual animal another time. Frankly, this picture (by Michael Skrepnick) may be all you need. It’s a giant, duck-billed, horse-headed, hump-backed, air-filled, slow-moving ornithomimid that probably ate anything it could get its beak around. And between the two specimens, there’s basically an entire skeleton in there. That’s exciting.

But here, I’d like to talk about how this paper absolutely trumps Ibrahim et al.’s Spinosaurus paper (2014). Yeah, I know, it’s low-hanging fruit, but somebody has to point these things out. Also, you'll recall that I'm an English major (with a rhetoric focus) so it's within my wheelhouse.

The first thing I noticed: Lee et al. manage to cram more data into their paper than Ibrahim et al., even though the former is significantly shorter than the latter.

Deinocheirus (Lee et al.): Four total pages in the main description, only two of which are text, eighteen pages of text in the supplementary file, and eight pages of "extended data" figures and tables. These may as well be counted as parts of the supplementary file, so let's say four pages of description (only two of which are text) and twenty-six pages of supplement. Total: thirty pages.

Spinosaurus (Ibrahim et al.): Three pages in the main description, only two of which are text, a whopping forty-eight-page supplement, and three pages of "extended data" figures and tables. These may as well be counted as parts of the supplementary file, so let's say three pages of description (only two of which are text) and fifty-one pages of supplement. Total: fifty-four pages.

Notice that it's been more than a week, and any sort of social media/blogosphere backlash against Deinocheirus is nowhere to be found. This despite the fact that Lee et al. are describing a similarly-legendary dinosaur previously known from intriguing but frustrating remains and rebooting it entirely. The two even share a love of piscivory. Lee et al. have produced a bizarre-looking, sail-backed, piscivorous animal that is very different from its relatives. In a way, Spinosaurus and Deinocheirus couldn't be more similar.

But nobody is batting an eye about the ostrich dinosaur. Meanwhile, the paleo community is STILL discussing Spinosaurus, although discussion has slowed considerably now that Ibrahim et al. have told us all stop talking while they write the monograph.

Here's the difference: Lee et al. are very reasonable--conservative, even--in their conclusions, do not make questionable assumptions, and wrap up every loose end. They don’t say anything like “it must have been a quadruped” and then never discuss how a quadrupedal theropod would work. The Internet took that ambiguity and ran with it. By contrast, Lee et al.’s most daring assertion is that Deinocheirus was a slow-moving omnivore. And they back that statement up—it has a long femur, broad pedal unguals, a therizinosaur-like ilium, sacrum that tilts the dorsal spine upward, and relatively short metatarsals. Stomach contents include over a thousand gastroliths and fish bones.

Miraculously, all of these details are written up in the main body of the description. You don’t need to go to the supplementary file to find the details. The supplementary file is really just an extension of the description proper, with a more thorough bone-by-bone analysis and a discussion about how the skeletons came to be found.

This is not the same as...

This. One of them is a misleading composite, and one is a responsible composite.

The figures are also much better. The front page includes photographs of the two specimens in a neutral, non-ambiguous pose so that readers can see how much of each specimen exists, then a skeletal reconstruction in a neutral, non-ambiguous pose as a composite. This is exactly the opposite of how Spinosaurus was shown: a CG model in a swimming pose that misrepresented the length of the femur* and did not adequately explain how much of a composite the new skeletal was. And while there are some photographs in the supplementary file, there weren't nearly enough to get an idea of exactly how much Spinosaurus aegypticus material was known.

I sense that if we saw the new Spinosaurus specimen by itself, there wouldn’t be much to see. No such guesswork is required for Deinocheirus: what you see is what actually exists.

As I said, the supplementary file includes an interesting narrative about how the Deinocheirus specimens were discovered, tracked down, and brought together. The Spinosaurus supplementary file includes a lengthy series of specimen referrals and a poorly-justified case for designating a neotype. The Deinocheirus paper includes excellent photographs of the skull and other bones, along with interpretive line drawings. The Spinosaurus supplementary file includes a drawing of Spinosaurus’ skull with known skull bones colored blue. There are no photographs of those bones. I know from reviewing past literature that these blue bones are a composite, but Ibrahim et al.'s paper does not state that fact.

This is not the same as...

This. One of them is a misleading composite. The other is a photograph and line drawing.

To me, it boils down to this:

Lee et al. say “Look at this thing we found.”

Ibrahim et al. say “Take our word for it, and wait an indeterminate amount of time for the monograph.”

Only one of those statements is good science.

Here’s what the Lee et al. paper proves: you can have good figures, good description, good conclusions, and unambiguous assertions in a brief paper. The Deinocheirus paper does NOT read like an extended abstract or poster presentation. My previous assertion that you simply can’t have a good, detailed paper in Nature or Science is wrong. You clearly can. While I think we all would have preferred to read about Deinocheirus in an open-access journal with more room for multiple, large figures, I'm impressed that Lee et al. were able to work within the restrictions of Nature and produce a quality paper. Despite being twenty-four pages shorter (in all), there is simply no question that Lee et al. have produced a far more comprehensive, reasoned, thoughtful, and descriptive scientific article than Ibrahim et al.

There are lessons to take from this comparison, and I hope writers do take them.

I hope you enjoyed this post, and congratulations to Lee et al. on this stunning discovery. I may have a new favorite giant dinosaur.

*Recall that, in their post at Scott Hartman's website, the authors note the following:

“Also, in the 3D model, the femur is not hanging straight down—it is angled outward/laterally slightly and so foreshortened slightly in lateral view, making it look shorter.”

As I said before, there's no use in putting ambiguity in your description. It leads to Scott Hartman and others trying to figure out where things went wrong.