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The microstructure of Smets' "dinosaur" revealed the fossils to be petrified wood. From Hovelacque, 1890.

Naming a new dinosaur is a tricky thing. More often than not, previously unknown dinosaurs first appear as bits and pieces, and more than a few dinosaurs have been established on little more than isolated teeth. Thanks to the uncertainties often inherent in describing new dinosaurs, sometimes what seem to be novel species turn out to be parts of previously known animals. That’s just how science works—ideas are constantly being investigated and tested. But I’m sure that was little consolation to a 19th century scientist who mistakenly named a new dinosaur from petrified plants.

In 1887, naturalist Abbe G. Smets announced the discovery of Aachenosaurus multidens. Not much of the organism survived in the fossil record—just two dark-colored fragments—but Smets was so confident in his ability to restore the whole animal that he issued a full-scale restoration of a Hadrosaurus-like dinosaur.

Other naturalists were not impressed. Paleontologist Louis Dollo and botanist Maurice Hovelacque didn’t see a dinosaur in the fossil pieces. The fragments, Dollo and Hovelacque concluded, were actually bits of fossil wood!

Smets was outraged. How dare Dollo and Hovelacque deride his discovery? Smets viciously attacked his peers in print, but this only undermined his case. The microstructure of the fossils clearly revealed them to be wood, not bone, and Smets’ anger could not change that fact. As naturalists G.A. Boulenger and Richard Lydekker wrote in a 1889 Geological Magazine article about the controversy, Smets appeared to:

… have followed the Old Bailey maxim, that when you have no case, the only thing left is to abuse the plaintiff and all connected to him.

Indeed, Boulenger and Lydekker were especially aggravated to find that Smets had attempted to use their research to discredit Dollo and Hovelacque. Both men were well-respected naturalists and no amount of name-calling by Smets was going to change that. Smets was only making a fool of himself by trying to turn other naturalists upon each other, and his wooden dinosaur rotted away.

A full-size restoration of what Aletopelta might have looked like, at the San Diego Natural History Museum. Photo by the author.

Dinosaurs created temporary reefs. At least, the ones whose bodies floated out to sea did.

Even though there were no aquatic dinosaurs, dead dinosaurs sometimes washed down rivers to the coast. When their bodies settled on the ocean bottom, scavengers of various sorts and sizes glommed onto the dinosaurs and formed short-lived communities with their own ecological tempo—perhaps similar to what happens to the carcasses of modern whales. The Cretaceous dinosaur bones found in my home state of New Jersey are the result of this kind of transport and marine breakdown, and other examples have been found at sites around the world.

Even bodies of the heavily armored ankylosaurs were sometimes swept out to sea. They must have been quite a sight—a bloated, belly-up ankylosaur, drifting for as long as the gases inside its body could keep it afloat. One of these dinosaurs, found miles from the closest land at that time, was recently discovered in the oilsands of Alberta, Canada, but this wandering ankylosaur isn’t the only one we know of. When I visited the San Diego Natural History Museum last month, I saw another.

Hung on the wall, the creature was less than half the dinosaur it used to be. Even though additional parts of the dinosaur were recovered when it was excavated during the construction of the Palomar-McClellan Airport in 1987, the articulated hindlimbs and adjoining hip material is what museum visitors are greeted with. (The rest sits in the collections.) At first glance, the specimen doesn’t look like much. But what makes this fossil so strange is the group of associated creatures. Embedded on and around the dinosaur bones were shells from marine bivalves and at least one shark’s tooth. This ankylosaur had settled and been buried in the sea off the coast of Cretaceous California.

Tracy Ford and James Kirkland described the ankylosaur in a 2001 paper included in The Armored Dinosaurs. Previously, the specimen didn’t have a proper scientific name. The dinosaur was simply referred to as the Carlsbad ankylosaur. And the details of the dinosaur’s armor, especially over the hips, seemed to be quite similar to that of another dinosaur called Stegopelta. This would make the Carlsbad ankylosaur a nodosaurid, a group of ankylosaurs that typically have large shoulder spikes but lack a tail club.

After reexamining the specimen, though, Ford and Kirkland came to a different conclusion. The dinosaur’s armor identified it as an ankylosaurid, the armored dinosaur subgroup that carried hefty, bony tail clubs. The club itself was not discovered, but the rest of the dinosaur’s anatomy fit the ankylosaurid profile. And the dinosaur was different enough from others to warrant a new name. Ford and Kirkland called the ankylosaur Aletopelta coombsi. The genus name, meaning “wandering shield,” is a tribute to the fact that the movements of geologic plates had carried the dinosaur’s skeleton northward over the past 75 million years.

We may never know exactly what happened to this Aletopelta. Detailed geological context is essential for figuring out how a skeleton came to rest in a particular spot, and that information was destroyed with the excavation of the skeleton. Still, paleontologists have put together a general outline of what happened to this dinosaur. The unfortunate ankylosaurid died somewhere along the coast, and its carcass was washed out to the sea by a river, local flood, or similar watery mode of transport. Aletopelta settled belly-up and was exposed for long enough to become a food source and even home for various organisms. Sharks and other larger scavengers tore at the carcass, but various encrusting invertebrates also settled on the skeleton. Fortunately for paleontologists, the skeleton was sturdy enough to survive all this and eventually be buried. Even though dinosaurs never lived in the marine realm, their deaths certainly enriched the sea.

References:

Ford, T., Kirkland, J. 2001. Carlsbad ankylosaur (Ornithischia: Ankylosauria): An ankylosaurid and not a nodosaurid. pp. 239-260 in Carpenter, K., ed. The Armored Dinosaurs. Bloomington: Indiana University Press.

Hilton, R.P. 2003. Dinosaurs and Other Mesozoic Reptiles of California. Berkeley: University of California Press. pp.39-40

That sauropod looks quite frustrated. These dilapidated dinosaurs rest at Berlin's abandoned Spreepark. Photo by Flickr user davidrush.

In an abandoned Berlin amusement park, dinosaurs are slowly suffering a second extinction. The creatures, attractions at what was once the German Democratic Republic’s Kulturpark Plänterwald, have toppled over, are decorated with graffiti and are slowly rotting away in a setting perfect for a Scooby-Doo episode or another tedious found-footage horror film (your choice).

A felled Stegosaurus at Berlin's Spreepark. Photo by Flickr user extranoise.

Kuriositas recently laid out the park’s backstory. When the static dinosaurs were put in place, Kulturpark Plänterwald was in Soviet-controlled East Berlin. The theme park was the only one on the communist side of the Berlin Wall. But when East and West Germany reunited in 1989, the park quickly collapsed. Even though the attractions at the relabeled Spreepark were expanded, a lack of parking and an unpopular single-price entry fee rapidly cut attendance. By 2001, the park was mired in a pit of debt with no way out. Spreepark closed, and the dinosaurs have gradually been decaying ever since.

For more photos, see the Kuriositas blog post about Spreepark.

Have you seen a dinosaur or other prehistoric creature in an unusual place? Please send a photo to dinosaursightings@gmail.com.

A pair of Pachycephalosaurus face off at the Museum of Ancient Life in Utah. Photo by the author.

Did dome-headed dinosaurs really butt heads? While not one of the most important subjects in paleontology, the question is one of the most fraught. The thick-skulled dinosaurs look as if they were perfectly suited to cracking heads, much like modern bighorn sheep do, but whether or not dinosaurs like Pachycephalosaurus really knocked noggins has depended on who you asked. While some studies have concluded that these dinosaurs were fully capable of bashing skulls, other analyses have disagreed and pointed out that rounded, dome-shaped heads were actually poor weapons in such contests.

The evidence from bone histology and the estimated defensive capabilities of pachycephalosaurs is ambiguous. But a conspicuous lack of skull pathologies seemed to support the idea that these dinosaurs were not butting heads, but instead rammed each other in the flanks or used their domes primarily as flashy ornaments. If pachycephalosaurs were regularly crashing headlong into one another, we would expect many of their skulls to show impact damage from such encounters.

For many years, no one had recorded the expected injuries. That changed this week thanks to a new PLoS One paper by Joseph Peterson and Christopher Vittore. The subject of their paper, titled “Cranial pathologies in a specimen of Pachycephalosaurus,” is a damaged portion of skull from the largest and most famous of all the dome-headed dinosaurs.

The dinosaur’s skull looks as if someone went at it with a hammer. Two large depressions—augmented by numerous smaller pits inside and along their margins—pock the top of the dome. Peterson and Vittore considered several possibilities, including damage caused to the bone after the animal’s death, bone resorption and trauma incurred during the dinosaur’s life. Injury followed by infection seems to be the explanation most consistent with the evidence. And this may not be the only skull of its kind. Towards the end of the paper, Peterson and Vittore point out that a skull of the pachycephalosaur Gravitholus and another belonging to Texacephale appear to have similar injuries to the top surfaces of their skulls.

Case closed, right? This would seem to be pretty good evidence that Pachycephalosaurus really did butt heads. But we should take care in how far we extend hypotheses from one skull. The injuries on the Pachycephalosaurus skull accord with the idea that these dinosaurs were butting heads, but we can’t actually know what happened to this particular dinosaur. The case for head-butting dinosaurs just got a boost, but it would be premature to say whether pachycephalosaurs definitely did or did not engage in the behavior on a regular basis. If the dinosaurs commonly crashed craniums, other damaged domes should be out there. There may be some waiting in the rock or sitting on museum shelves. One thing seems certain, though—Peterson and Vittore’s dinosaur probably had one hell of a headache.

For more on this research, see David Orr’s post at Love in the Time of Chasmosaurs.

Reference:

Peterson, J., & Vittore, C. (2012). Cranial Pathologies in a Specimen of Pachycephalosaurus PLoS ONE, 7 (4) DOI: 10.1371/journal.pone.0036227

A promotional image, featuring a baby Pachyrhinosaurus, for Walking With Dinosaurs 3-D.

Are we about to experience another burst of Dinomania? Maybe. Dinosaurs already have a ubiquitous cultural presence, but nothing drives interest in the beloved prehistoric creatures like Hollywood films. A stampede of dinosaur flicks is set to debut over the next two years.

A few dinosaur features fall somewhere on the educational spectrum. The Werner Herzog-narrated Dinotasia—a re-blended version of the miniseries Dinosaur Revolution—is set to traumatize children who have no idea who Werner Herzog is. And the long-running Walking With Dinosaurs series is scheduled to launch a 3-D sequel sometime next year. The plot for the new installment, set in Cretaceous Alaska, sounds awfully similar to the televised special March of the Dinosaurs.

Not all the upcoming dinosaur dramas are documentaries, though. Pixar recently announced the title of its 2014 feature The Good Dinosaur. The plot plays a little loose with evolutionary theory to bring people and dinosaurs in contact with each other. But the rest of the cinematic dinosaurs are not going to be so friendly. Jurassic Park will get a 3-D conversion for the movie’s 20th (!) anniversary in 2013, and not wanting to be left out, Warner Brothers is apparently working to loose  “a pack of rapidly evolving dinosaurs into the heart of contemporary Los Angeles.” The idea sounds a bit like 2001′s Evolution, which released extremely adaptable aliens into Arizona. Maybe the studio competition will turn the rumors of Jurassic Park 4 into something more tangible, but who knows? Dinosaurs vs. Aliens, one of the latest ideas to exploit the seemingly bottomless limits of the versus subgenre, may hit screens before the Jurassic Park franchise evolves.

From the looks of it, there will be a little something for everyone, from friendly manifestations of childhood dreams to rampaging, bloodthirsty tyrannosaurs. I’m hoping for beautifully rendered feathers, recently discovered dinosaurs we’ve never seen restored before, and a respect for dinosaurs that doesn’t treat them as mindless monsters or just kid’s stuff, but I guess we will have to wait and see. Non-avian dinosaurs vanished around 66 million years ago, but we love to bring them back to life on screen.