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The track of an Early Jurassic theropod dinosaur at St. George, Utah's Dinosaur Discovery Site. This track is of the same general type and close of the age of the tracks recently found near Las Vegas. Photo by the author.

Earlier this month, paleontologists from around the world convened in Las Vegas for the 71st annual Society of Vertebrate Paleontology conference. Preliminary findings were shared, new discoveries were presented, and researchers caught up with friends and colleagues, but not all the news came from the meeting halls. Various field trips held just before the conference introduced paleontologists to the geology and paleontology in the vicinity of Las Vegas, Arizona, and southern Utah. One of them confirmed the traces of a dinosaur not far from the bright lights of the Las Vegas strip.

An article in the Las Vegas Review Journal has the details. About twenty minutes outside of Las Vegas, within the Red Rock Canyon National Conservation Area, lie the tracks of a relatively small theropod dinosaur in the red, roughly 190-million-year-old Early Jurassic rock. Our knowledge of dinosaurs in North America from this time is relatively sparse. Very few skeletons have been found from this period, and much of what we know about the dinosaurs of the Early Jurassic Southwest comes from tracksites. For the moment, these three claw-tipped toe impressions indicate that the Red Rock Canyon dinosaur was a small theropod. Details of the dinosaur’s behavior, such as how fast it might have been walking, have not yet been studied.

The interpretation of the Red Rock Canton site will emerge as research is conducted. According to the LVRJ story, Bureau of Land Management officials are planning to create casts of the tracks to let visitors learn about the site without risking damage to the ancient footprints. If you’re in the area and are really itching to see some dinosaur tracks, though, there are other opportunities within a few hours drive: the Dinosaur Discovery Site in St. George, Utah is packed with similar Early Jurassic dinosaur footprints.

We just can’t get away from Jurassic Park. Though the original film adaptation of Michael Crichton’s novel debuted 18 years ago and the last sequel is now a decade old, a slew of toys, comics, games, fan tributes and rumors of a fourth movie have kept the franchise alive. Now Telltale Games has issued its own entry to the list of Jurassic Park spinoffs: an adventure that goes back to the scene of the crime that set the catastrophic events of the first film in motion.

Remember that can of Barbasol from the first Jurassic Park film? The one containing all those very, very expensive dinosaur embryos? Well, that’s the MacGuffin at the heart of Jurassic Park: The Game. Within the context of the new game, the corporate spies who commissioned the nefarious Dennis Nedry to steal the precious little dinosaurs didn’t entirely trust his ability to complete the task. They sent in a back-up: a professional smuggler named Nima.

As with anything in Jurassic Park, though, the best laid plans of Microraptor and men go awry. Nima quickly gets tangled up in a race to escape the island alive. Other characters are park veterinarian Gerry Harding, Harding’s daughter Jess, a couple of mercenaries sent to evacuate the park and a park scientist who is more concerned about the dinosaurs than the safety of her companions. This all takes place in the hours during and directly following the first film, making the game a parallel storyline that fits snugly within the cinematic Jurassic Park canon.

The new game isn’t another run-and-gun dinosaur shooter. There are more than enough of those out there already—using a rocket launcher against hordes of Velociraptor isn’t a rare gaming experience anymore. Nor does the game primarily feature major characters from the films or let you play as dinosaurs, as past Jurassic Park games have done. Instead, Jurassic Park: The Game is akin to a movie that the player directs through puzzles and action sequences requiring specific actions to solve. One moment you’ll be frantically trying to hit the proper combination of keys to prevent yourself from tripping while running away from Tyrannosaurus, and the next you will have to figure out the proper door code to enter a locked area. And the story unfolds not through just a single character’s perspective—the game requires players to jump between characters to accomplish certain tasks. The storyline propels the player, but only as fast as you can successfully navigate through the puzzles.

This type of game setup is both refreshing and extremely frustrating. During many parts of the story, players must observe their surroundings and use what’s at hand to solve puzzles to keep from being chomped by various theropods, and a dialog option allows players to take certain parts of the game at their own pace. During lulls in the action, players can dig into the backstory of various characters through conversation prompts. At one points, for example, you can stop to chat with Nima about why the island means so much to her, or you can decide to just move on to the next puzzle. The action sequences are a different story. Players are required to hit certain combinations of keys in rapid succession in order to escape packs of Troodon, avoid charging Triceratops and stab attacking Velociraptor, but these events require such speed and deftness at the keyboard or gamepad that a player is almost guaranteed to fail the first few tries. An adventure game should be challenging, of course, but many of the action prompts require such a high level of responsiveness or even anticipation that sequences meant to be fun and exciting quickly became annoying.

As for the look of the game, the designers kept appearances consistent with the original film. The park buildings, fences and vehicles match those from the movie, and the dinosaurs match their big-screen counterparts. As much as I would have loved to have seen feather-covered Velociraptor, the only reasonable choice was to keep the designs consistent. Some of the prehistoric beasts new to the game could have used a little more work, though. The Herrerasaurus are a bit too tubby and have skulls that more closely approximate the look of true Velociraptor than the genetically engineered monsters given that name in the game, and the mosasaur in the final chapter was given a number of flourishes which made the marine reptile look more like a sea monster than a real animal. The game designers appear to at least minimally respect hard-core dinosaur nerds, though: Snippets of dialog and journal entries in the game retcon a few of the scientific issues with the fictional story and even include some up-to-date science.

Despite my quibbles about the new prehistoric threats and some elements of the gameplay, though, Jurassic Park: The Game is an enjoyable and well-executed spinoff that lets players venture deeper into the dinosaur-infested park. The game reminded me of the “choose your own adventure” books I read as a kid—the choices you make as the story unfolds will either open up the next scene or send you spiraling into certain doom. That approach, I think, captured the spirit of the Jurassic Park films. A return to the island may not be safe, but it is fun.

A reconstruction of Pampadromaeus. From Cabreira et al., 2011.

November has been a good month for sauropodomorph fans. Earlier this week I wrote about Leyesaurus, a newly named dinosaur that was part of a diverse cast of creatures preceding the mighty, long-necked sauropods. Now paleontologist Sergio Cabreira and colleagues have named another, even older relative of this peculiar group: Pampadromaeus barberenai. This animal may provide some hints about what the ancestral dinosaur might have been like.

Attendees at the 71st annual Society of Vertebrate Paleontology meeting got a preview of Pampadromaeus courtesy of study author Max Langer a few weeks ago. The study published in Naturwissenschaften goes into more detail. The newly described dinosaur is remarkable for both the location of its discovery and its placement in the dinosaur evolutionary tree. While many of the earliest known dinosaurs, such as Eoraptor and Panphagia, have been found in the Late Triassic strata of Argentina, Pampadromaeus was excavated from roughly 230- to 228-million-year-old, Late Triassic deposits in southern Brazil. Most of the skeleton was found, including the majority of the skull.

But what truly makes Pampadromaeus stand out is the dinosaur’s intermediate place between some of the earliest known dinosaurs and the later, more specialized sauropodomorphs such as Leyesaurus and Plateosaurus. While the skull of Pampadromaeus is long, low and generally resembles those of sauropodomorphs, the newly described dinosaur had different kinds of teeth in the jaw. Leaf-shaped teeth thought to correspond to herbivory were set in the front, while an array of short, recurved teeth often associated with carnivory followed toward the back of the mouth. Perhaps Pampadromaeus was an omnivorous dinosaur not yet fully committed to a life of chewing on plants. The anatomy of the rest of the dinosaur’s approximately four-foot-long body is consistent with a unique and varied lifestyle. Pampadromaeus had long legs and comparatively short arms, which hint that the dinosaur was an obligate biped. It seems unlikely that Pampadromaeus switched between walking on two legs and all fours as in later sauropodomorphs.

Taken together, the skeletal traits may indicate that Pampadromaeus retained features of what is thought to be the ancestral dinosaur archetype: a bipedal carnivore or omnivore similar to Eoraptor. Exactly where the dinosaur fits in relation to sauropodomorphs is difficult to ascertain, however. Several analyses in the new study place Pampadromaeus just outside the sauropodomorph group, which may indicate that the dinosaur represents a “stem” lineage from which the true sauropodomorphs evolved. Further discoveries and analyses are required to provide the context necessary to understand where Pampadromaeus belongs in relation to these dinosaurs. Still, Pampadromaeus is more closely related to the early sauropodomorphs than to the forerunners of theropod dinosaurs. By comparing the anatomy of such a creature to theropod foreunners such as Herrerasaurus and Staurikosaurus, perhaps paleontologists will be better able to understand what the common ancestor of the sauropods and theropods was like and reconstruct one of the great splits in the evolutionary history of dinosaurs.

References:

Cabreira, S., Schultz, C., Bittencourt, J., Soares, M., Fortier, D., Silva, L., & Langer, M. (2011). New stem-sauropodomorph (Dinosauria, Saurischia) from the Triassic of Brazil Naturwissenschaften DOI: 10.1007/s00114-011-0858-0

The reconstructed skull of Marshosaurus at the Natural History Museum of Utah. Photo by the author.

Eastern Utah’s fossil-filled Cleveland-Lloyd quarry is best known for its fossils of Allosaurus. From the time the site was opened in 1929 to the present, the scattered remains of at least 46 Allosaurus have been collected from the roughly 147-million-year-old slice of Late Jurassic rock. But Allosaurus has not been the only dinosaur found there. Rare pieces the huge herbivores Barosaurus, Camarasaurus, Camptosaurus and Stegosaurus have been picked out of Cleveland-Lloyd, as have the remains of other predatory dinosaurs such as the early tyrannosauroid Stokesosaurus, the massive Torvosaurus, the well-ornamented Ceratosaurus and a poorly known theropod named Marshosaurus.

Up until about a year ago, I had never heard of Marshosaurus. Allosaurus, Ceratosaurus and, to a lesser extent, Torvosaurus were traditionally promoted as the predators of the Late Jurassic in North America. That’s why I was surprised to see the restored skull of Marshosaurus set into an explanatory display in the Carnegie Museum of Natural History during the reception at last year’s Society of Vertebrate Paleontology conference. The skull looked slender and quite unlike the deep skulls of the bigger Morrison theropods I had previously learned about. What was this dinosaur?

Marshosaurus was not a new dinosaur that had slipped under my radar. Quite the opposite. In 1979 paleontologist James Madsen, Jr. named and initially described the dinosaur on the basis of a virtually complete pelvis and a few elements of the upper jaws found in the Cleveland-Lloyd quarry. Madsen acknowledged that this wasn’t much to describe a new genus from and lamented that there was simply not enough funding to sift through, prepare and study the dozens of other bones at the site that might belong to the new, relatively small dinosaur. Nevertheless, the known parts of the theropod were clearly different from those of other dinosaurs found at the site, including small Allosaurus, and so Madsen gave the creature the title Marshosaurus bicentismus in honor of the famous paleontologist Othniel Charles Marsh and the bicentennial anniversary of the United States of America.

Parts of Marshosaurus later turned up in other dinosaur bonebeds. Additional skull material, a partial vertebral column, and other portions of the skeleton were found at northeastern Utah’s Dinosaur National Monument in a slightly geologically older part of the Morrison Formation called the Salt Wash Member. (The Cleveland-Lloyd site is part of the stratigraphically higher Brushy Basin Member.) Taken together, the collected remains of Marshosaurus seem to represent an approximately 18-foot-long predator which was in a lower weight class than the giant Allosaurus and Torvosaurus of the same environments. What variety of theropod Marshosaurus was, however, has been unclear until recently.

In his 2010 revision of the dinosaur Megalosaurus, paleontologist Roger Benson included Marshosaurus in his analysis of theropod relationships. Benson found Marshosaurus to be a relatively basal member of the Megalosauroidea—a large and varied group of predatory dinosaurs which presently includes the sail-backed spinosaurs in one subgroup and dinosaurs such as Torvosaurus and Megalosaurus in another. This would mean that Marshosaurus would be an early and archaic member within this large group which generally represents the form of the megalosauroids before the big split between the Spinosaurus and Torvosaurus lineages. Further analyses will test these hypothesized relationships, and perhaps additional Marshosaurus material will be identified from places like Dinosaur National Monument and the Cleveland-Lloyd quarry in the future. We still know very little about this dinosaur. For one thing, how did this relatively small carnivore make a living alongside so many other more imposing predators?

References:

Benson, R. (2010). A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods
Zoological Journal of the Linnean Society, 158 (4), 882-935 DOI: 10.1111/j.1096-3642.2009.00569.x

Madsen, J. 1979. A second new theropod dinosaur from the Late Jurassic of east central Utah. Utah Geology 3(1): 51–60.

I have often been accused of being a fossil killjoy. I regularly disappoint paleontology fans who prefer to see prehistory as a constant battle of all against all. But them’s the breaks—as we understand the fossil record better, sometimes prehistory turns out to be less blood-spattered than we thought.

One of the most recently revised cases involved the approximately 100-million-year-old Lark Quarry in Australia. This place, an immense tracksite, is said to preserve the signs of a seldom-seen dinosaur stampede. The old story went something like this. A huge aggregation of small, bipedal dinosaurs were hanging out along the shore of an ancient lake. The small dinosaurs had no idea they were being watched by hungry eyes. Without warning, a huge carnivorous dinosaur burst from its cover in a nearby stand of trees. Little dinosaurs scattered everywhere, leaving behind evidence of a dinosaur stampede.

There is no doubt that a huge gaggle of little dinosaurs scurried away over the damp Cretaceous lake shore. What has come into question is the identity of the dinosaur that triggered the stampede. The dramatic predator vs. prey story was based on large, three-toed footprints found at the same site. These were previously attributed to a large theropod dinosaur akin to Allosaurus—the recently-discovered Australovenator seemed to be a good candidate—but a recent reanalysis by paleontologists Anthony Romilio and Steven Salisbury found that the imprints don’t actually match the foot anatomy of big predatory dinosaurs. Instead, the relatively blunt-toed tracks correspond to the feet of a herbivorous, iguanodontian dinosaur, something akin to Australia’s own Muttaburrasaurus.

This sort of revision has happened before. Many large, three-toed tracks attributed to tyrannosaurs and other predatory dinosaurs have later been found to belong to hadrosaurs and other herbivorous dinosaurs within a group called ornithopods. Rather than running for their lives, the little dinosaurs who left their footprints at the Lark Quarry site may have been yellow-bellied chickenosaurs that got spooked when a big herbivore got too close or surprised them. And even that scenario assumes that the big tracks and little tracks represent a single event. Something triggered the dinosaur stampede, but there is no solid evidence that a ravenous, sharp-toothed dinosaur was to blame.

Nevertheless, a new documentary about the Lark Quarry site created by the Australian Broadcasting Corporation has played up the drama of the traditional story. I have not been able to see the program yet—the show is only available to Australian viewers thus far—but the promotional trailer certainly emphasizes the role of a mysterious, carnivorous dinosaur. Maybe this is a bait-and-switch—build up the mystery, but then tell viewers that a wandering herbivore was really responsible. Then again, maybe the old story is just too hard to resist. Prime-time dinosaur documentaries are made of flesh-tearing predators, not bumbling ornithopods. Personally, I think a comedic angle—little dinosaurs tripping over themselves as Boots Randolph’s rendition of “Yakety Sax” played in the background—would be just as fitting as the dramatic, terror-laden one, but dinosaur documentary tradition is hard to break.