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A skeletal restoration of Smok wawelski. The black parts are missing elements of the skeleton. From Niedźwiedzki et al, 2011.

Sometimes fossils aren’t what they initially seem.

Back in 2008, paleontologists Jerzy Dzik, Tomasz Sulej and Grzegorz Niedźwiedzki presented what they believed was a big predatory dinosaur from an approximately 200-million-year-old Late Triassic site in Lisowice, Poland. They gave it the nickname “The Dragon of Lisowice,” and in a short summary of the find, Sulej and Niedźwiedzki speculated that the then-unnamed creature “may have initiated the evolutionary line that would eventually culminate in the famous super-predator Tyrannosaurus rex.” The Dragon was thought to signify the dawn of truly terrifying theropod dinosaurs, but it turns out this carnivore may have been a particularly imposing member of a very different lineage.

When first mentioned in the 2008 paper, the predator from prehistoric Poland was said to be known from various skeletal elements that may represent two individuals. An dinosaur-like skeleton was reconstructed on the basis of these partial remains, and now an in-press version of a paper describing the animal by the same researchers has become available through the journal Acta Palaeontologica Polonica. Now the “dragon” has a name: Smok wawelski.

The new paper records some changes from the earlier report. For one thing, the various skeletal scraps found at the excavation site are said to belong to a single individual and not two as originally hypothesized. More significantly, though, the proposed family relationships of Smok have been changed.

Despite being touted as an Allosaurus ancestor shortly after its discovery, in the new paper Smok is simply called “a new large predatory archosaur.” This is a very general statement. The Archosauria is a huge group of vertebrates whose first members evolved more than 240 million years ago; it includes crocodylians, pterosaurs, dinosaurs and various extinct lineages closely related to these major groups. Of these, Niedźwiedzki and colleagues state that Smok shows resemblances to both theropod dinosaurs and a group of extinct, land-dwelling crocodile cousins called rauisuchians, though distinguishing which lineage the animal should be assigned to is difficult. Smok is definitely some kind of archosaur, but precisely what branch of the archosaur family tree it belongs on has not yet been fully resolved.

Exactly what Smok is requires further research to sort out—the paper states that Niedźwiedzki is working on this issue as part of his PhD thesis—but the prospect that it was a dinosaur doesn’t look good. As Bill Parker and others have commented elsewhere, Smok is almost certainly more closely related to crocodile-line archosaurs than to dinosaurs. Characteristics of the skull and hips, especially, underscore this as the most likely possibility. The overall resemblance of Smok to large predatory dinosaurs is a result of evolutionary convergence, or the independent evolution of characteristics in distantly related groups, and the dinosaurian appearance of the reconstructed skeleton was primarily created through using a dinosaur-like template for the known remains.

This isn’t the first time a carnivorous croc-relative has been mistaken for an ancestor of big, bad theropod dinosaurs. In 1985, paleontologist Sankar Chatterjee described a large Triassic predator he called Postosuchus. Described as “the arch predator of its time,” Postosuchus was correctly identified as being a rauisuchian, but Chatterjee also believed that the predator also exhibited traits that foreshadowed those seen in Tyrannosaurus many millions of years later. In fact, Chatterjee proposed that many major characteristics seen in tyrannosaurs were present in Postosuchus, and therefore the Triassic creature “may [have been] close to the ancestry of tyrannosaurs.”

Chatterjee was wrong about Postosuchus being the rootstock for tyrannosaurs. Rauisuchians had nothing to do with the ancestry of Tyrannosaurus or any other dinosaurs—they were a unique group of creatures more closely related to crocodiles which overlapped in time with early dinosaurs. (The tyrannosaurs, instead, originated from small, feather-covered coelurosaurian dinosaurs which looked quite different from the latest and most famous members of the group.) The resemblances Postosuchus and Smok share with large predatory dinosaurs are the results of convergence and are not true signals of close evolutionary relationships. Dinosaur or not, though, these rauisuchians were still formidable and terrifying predators. A terrestrial, 16-foot, carnivorous crocodile-like predator is not something I would like to meet in a dark alley (or anywhere else, really).

References:

Chatterjee, S. (1985). Postosuchus, a New Thecodontian Reptile from the Triassic of Texas and the Origin of Tyrannosaurs Philosophical Transactions of the Royal Society B: Biological Sciences, 309 (1139), 395-460 DOI: 10.1098/rstb.1985.0092

Dzik, J., Sulej, T., & Niedźwiedzki, G. (2008). A Dicynodont-Theropod Association in the Latest Triassic of Poland Acta Palaeontologica Polonica, 53 (4), 733-738 DOI: 10.4202/app.2008.0415

Niedźwiedzki, G., Sulej, T., Dzik, J. (2011). A large predatory archosaur from the Late Triassic of Poland Acta Palaeontologica Polonica DOI: 10.4202/app.2010.0045

Sand sculpture dinosaurs, as seen in Albufeira, Portugal. Courtesy reader Sean Markey.

I’m not that good making sand sculptures. Give me a pail and a shovel and I can make a rockin’ series of turrets for a sand castle, but the finer points of sand art elude me. That’s why this beach sculpture seen in Albufeira, Portugal is so impressive. Sent in by reader Sean Markey, the art shows a group of carnivorous dinosaurs chowing down on a sauropod dinosaur, much like some of the Late Jurassic dinosaurs of that country’s Lourinhã Formation must have done. I don’t know how likely an Allosaurus would have been to share with a hungry Torvosaurus in real life, though.

Back in 1918, special effects artists had to make dinosaurs the old-fashioned way. Creating sculptures out of clay and bringing them to life through stop-motion animation was the only way to go, and the pioneering artist in this medium was Willis O’Brien. He’s probably best known for his work on King Kong—the giant ape and Skull Island’s dinosaurs were his creations—but O’Brien also made a number of silent short films which featured prehistoric creatures, including The Ghost of Slumber Mountain.

The plot is pretty simple. Uncle Jack tells his nephews about the time he went up to Slumber Mountain, (surprise!) fell asleep and dreamed of seeing prehistoric creatures through a magical telescope carried by a fellow named Mad Dick (who was played by O’Brien himself). The whole thing was mainly an excuse to get dinosaurs and other ancient critters on screen—the film’s tagline was: “These giant monsters of the past are seen to breathe, to live again, to move and battle as they did at the dawn of life!”

The short is just a shadow of what it was meant to be. Originally planned to be a feature film, the final product stretched only 18 minutes. Still, the movie was a financial success. According to the folks at Turner Classic Movies, it took about $3,000 to make the film but it brought in over $100,000 in profit. Not too shabby.

Although it’s usually only remembered by film buffs and dinosaur fans today, The Ghost of Slumber Mountain represents a significant milestone in the history of movies because it was the first time live actors were paired with stop-motion dinosaurs. This is the movie that got the ball rolling and gave O’Brien some of the skills he would later use on movies like The Lost World and Mighty Joe Young. Without it, we might never have seen Professor Challenger face dinosaurs on an South American plateau or seen a giant gorilla hang from the Empire State Building.

A hot pink Stegosaurus at the Dinosaur Ridge visitor's center. Photo courtesy David Schey.

I’ve seen plenty of roadside dinosaurs out here in the American West, and many of them come in muted shades of green and brown. There are a few exceptions to the rule, though, like this hot pink Stegosaurus spotted by reader David Schey at the Dinosaur Ridge visitors center in Morrison, Colorado. “Is this what paleontologists see after having one too many?” David wonders. I can confidently say, “no.” When I’ve had one too many, I see pink Allosaurus.

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

A reconstructed Tyrannosaurus rex at the Museum of Ancient Life. Photo by author.

A few months ago I took at look back at Jim Lawson’s dinosaur-centered series Paleo. This wasn’t like Disney’s Dinosaur, but a bloodier collection of tales about survival in the Late Cretaceous of North America. The comic’s run ended a few years back, that is, until Lawson started posting pages from his previously unpublished story “Loner” on the web.

As you might guess from the title, “Loner” is the tale of a solitary tyrannosaur. He is one hate-filled beast. In the first few pages alone our star contemplates devouring the young of a nearby female tyrannosaur for no other reason than to quell  his inner turmoil. Not exactly a sympathetic hero.

I won’t say more about the story here—you can check it out for yourself as the the tale continues. In regard to the artwork, though, “Loner” gets off to a rough start. The artwork is not as detailed as that in the original run of the series, and there are a lot of odd, sharp angles on the dinosaurs. The tyrannosaurs look pointy in places they shouldn’t. It’s also difficult to tell the individual animals apart—the book is filled with tyrannosaurs, each looks almost the same as any other. Thank goodness there are text panels to explain who’s who. Given the general lack of new dinosaur comics lately, though, I’m still glad to see Paleo back for another round.

[Hat-tip to Love in the Time of Chasmosaurs for tipping me off to Lawson's blog.]