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A restoration of the skeleton of Raptorex, just one of the amazing new dinosaurs announced in 2009.

It has been a good year for dinosaurs. Every month multiple new, interesting discoveries have been announced that either introduce us to new dinosaurs or tell us something new about those already familiar to us. I have been able to cover only a small fraction of all these stories here on Dinosaur Tracking, but here are some of my favorite dinosaur discoveries of 2009.

“Bone-Headed” Dinosaurs Reshaped Their Skulls. A few years ago it was announced that there was some evidence that what were once thought to be three distinct “bone-headed” dinosaurs were really just growth stages of Pachychephalosaurus. The research supporting this hypothesis was published this year, and while it is still being debated, it has opened up questions about the identity of other dinosaurs, too.

Miragaia, the Long-Necked Stegosaur. Stegosaurus was one weird dinosaur, but its long-necked relative Miragaia was even stranger.

New early dinosaurs. Questions about the early evolution of dinosaurs have perplexed scientists for years, but two new dinosaurs announced this year help fill in gaps in our understanding. The predatory dinosaur Tawa hallae and the early sauropod relative Panphagia protos have given paleontologists a new look at what early dinosaurs were like and how the giants of the Jurassic and Cretaceous got their start.

Tianyulong, an Unexpectedly Fuzzy Dinosaur. New specimens of feathered dinosaurs almost always make the news, but Tianyulong was extra-special. It was a dinosaur only very distantly related to birds that was preserved with simple, quill-like structures on its body, supporting the idea that many different dinosaurs might have had body coverings. Tianyulong is not to be confused with Tianyuraptor, a small predatory dinosaur found in the same region of China and also announced this year.

Gooey Hadrosaurs. Hadrosaurs are among the most useful dinosaurs for studying questions about dinosaur biology because they were so numerous and there are a number of exceptionally preserved specimens that give us a look at what their soft tissues were like. This year one team of paleontologists described the preserved skin of a hadrosaur nicknamed “Dakota” and another team studied remnants of blood vessels in a Brachylophosaurus. No doubt we will hear more about the soft tissues of hadrosaurs from both groups in the future.

Year of the Tyrants. It has been an excellent year for anyone who loves tyrannosaurs. Even if tyrannosaurs did not regularly chew on bones they did fight quite a bit (and maybe even ate each other), and their lack of dental hygiene might have assisted the spread of harmful microorganisms among the tyrant dinosaurs that still afflict birds today. And, on top of all that, several new members were welcomed into the tyrannosaur family, including two long-snouted killers and a miniature relative of Tyrannosaurus that will provide new insights into the evolution of some of the largest predatory dinosaurs that ever lived.

This is by no means a comprehensive list. There were plenty of other new discoveries and excellent studies published this year. What were some of your favorites?

The neck of the Sauroposeidon at the Oklahoma Museum of Natural History. Courtesy of Matt Wedel of SV-POW!

That’s Entertainment: In the wake of the “Clash of the Dinosaurs” fiasco, David Hone at Archosaur Musings, has drafted a brief “manifesto” on the dumbing-down of dino documentaries. “If you want your show to be a trashy dinosaurs fighting show then fine, do it,” Hone writes, “but please don’t pretend it’s a serious examination of palaeontology.” For more on the de-evolution of documentaries, see this earlier essay we posted on how sophisticated special effects are increasingly blurring the line between science and fantasy.

Artistic License Revoked: “Learn from my folly,” advises Craig Dylke at Art Evolved, who offers helpful tips on paleo-art after making some rather embarrassing mistakes in an attempt to accurately portray a Squalodon (a whale-like species with teeth).

Why Dinosaurs Matter: At the Whirlpool of Life, Scott Sampson pens an eloquent essay on why dinosaurs are more than “prehistoric eye-candy” and play a vital role in science education: “These ancient creatures can be used to demonstrate that every ecosystem on Earth, whether in the Mesozoic or the present day, is the culmination of millions upon millions of years of co-evolution between and among life forms. Since their heyday overlapped with the fragmentation of Pangaea, dinosaurs also provide an excellent forum for communicating the workings of plate tectonics and the physical evolution of our planet. They can even serve as able guides as we contemplate such pressing issues as global warming….and mass extinction.”

Neck the Halls: “Ever since we started working on Sauroposeidon, Rich Cifelli and I dreamed of seeing the reconstructed neck on display,” writes Matt Wedel at SV-POW! “That vision has come to fruition.” See their photos taken at the Oklahoma Museum of Natural History.

Y Not? The Disillusioned Taxonomist, who has been blogging an A-to-Z guide to British wildlife, was disillusioned to learn that not many scientific names begin with “Y.” Still, his determined research prevailed. Meet Yaverlandia bitholus.

Why Dinosaurs Hate Christmas: Ediacaran explains.

Not Amused: “I usually try to stay away from politics on my site—that’s one of the advantages of writing about creatures that have been dead for 65 million years,” notes Bob’s Dinosaur Blog. Yet Bob’s ire was raised by this political cartoon, suggesting that dinosaurs became extinct because they listened to the advice of climate change activists.

The poster for Avatar, with the pterosaur-like "Banshee" visible at the bottom.

Like many other people over the holiday break, I saw James Cameron’s blockbuster film Avatar. It was absolutely amazing. Set on a far-off world in the not-too-distant future, the film is a sort of Last Samurai or Dances With Wolves in space, but what really grabbed my attention were the creatures that lived on the planet on which the story unfolds.

In his 1989 book Wonderful Life, the paleontologist Stephen Jay Gould wondered what would happen if we could “rewind the tape” of evolution on earth and start it over from the beginning. Would the same organisms evolve, or would life look very different? Unfortunately we cannot actually run this experiment, but if we find life elsewhere in the universe it can act as a sort of test of Gould’s idea.

Granted, the creatures of Avatar are entirely speculative and in some cases are modeled closely on familiar animals, but they are still interesting interpretations of different forms evolution might toss up on another planet. Most of the creatures in the film, for example, are hexapods, meaning that they have six limbs instead of four. The earliest land-dwelling vertebrates on our planet, the ancestors of all amphibians, reptiles, birds, and mammals, had four limbs, but what if by some quirk they had six? What might their descendants look like millions of years later? The creatures of Avatar are imaginative answers to such questions. (Though the Na’vi, the planet’s humanoid inhabitants, have only four limbs, suggesting either a different ancestry or the recent loss of that “extra” pair of limbs.)

Most of the creatures in the film are vaguely mammalian, from the panther-like Thanator to the obviously equine Direhorse, but at least two creatures have a slightly more reptilian aspect. Both, the Mountain Banshee and the Great Leonopteryx, are brightly-colored flying creatures that are  a mix of different animals all stuck together as if some spare parts were just lying around. In general, though, they look like variations of the flying pterosaurs that thrived alongside the dinosaurs, and some prehistoric animals were even taken for inspiration in their design. According to creature creator Wayne Barlowe:

I was influenced by manta rays and skates – sea life motifs were prevalent in my thoughts at the time – when it came to my initial concepts. Their lines informed everything from wings to head profiles. And, yes, being a huge paleontology buff did make me think of the vast variety of relatively little-known pterosaurs and plesiosaurs with their many, unique aerodynamic and hydrodynamic solutions. [emphasis added]

There is much more that could be said about the creatures of Avatar, from their extra breathing holes to the way the Na’vi protagonists can interface with them using a sort of biological “plug and play” capability, but most of all they made me think of evolution. What if certain events in the history of life on our own planet had been different? What if the first terrestrial vertebrates had six legs, or what if the extinction that wiped out the non-avian dinosaurs never happened? We can never know for sure, but science-fiction films like Avatar allow special effects artists to take questions like these to create whole new worlds.

The vertebrae of an embryonic ichthyosaur preserved in the stomach of a plesiosaur. From the Journal of Vertebrate Paleontology paper.

Finding an articulated fossil skeleton is always a delight for paleontologists. Not only do such specimens illustrate how all those bones went together, but sometimes there are little associated bonuses that could not be seen if the skeleton had been scattered. In the case of a 161- to 155-million-year-old plesiosaur recently discovered in Wyoming, the marine reptile died with its last meal preserved in its stomach.

Today Wyoming is far removed from the sea, but during the Late Jurassic a body of water called the “Sundance Sea” covered what is now the “Equality State.” Numerous marine reptiles swam in those waters, including plesiosaurs and ichthyosaurs. When these reptiles were first found, they were often depicted as locked in mortal combat, two sea dragons that were destined to duel, but evidence of such awesome battles has not been found. What has now been recovered, however, is the skeleton of a plesiosaur similar to Pantosaurus striatus with the partially digested remains of a baby ichthyosaur inside.

As reported in the latest issue of the Journal of Vertebrate Paleontology, among the preserved stomach contents of the partially-complete plesiosaur skeleton there were a series of small, ring-shaped bones. At first the researchers did not know what they were, but they eventually recognized the vertebrae of a prenatal ichthyosaur (which was confirmed by the discovery of a jaw fragment from the same animal). This was very strange. Typically ichthyosaurs at so early a stage of development are found inside or in association with their mothers. What was it doing in the belly of a plesiosaur?

Exceptionally-preserved ichthyosaurs from Holzmaden, Germany might hold the answer. Some ichthyosaurs of the genus Stenopterygius have been found there with baby ichthyosaurs sticking out of what would have been their mother’s body cavity. It looks like the mother ichthyosaurs were preserved in the act of giving birth, but a more likely explanation is that the babies were being expelled from the body when the mother was either dead or dying. The babies might have been pushed out during the stress of death or the buildup of gases inside their mother’s body might have forced them out after death, and these babies would have been easy meals for predators that were passing by. The plesiosaur that was the subject of the new research probably scooped up the embryonic ichthyosaur after its mother had expelled it; there was probably no titanic battle like the one envisioned in Journey to the Center of the Earth.

No doubt some will find this disappointing, but it is still a significant find. This is the first time ichthyosaur remains have been found inside a plesioaur. And even though it might be difficult to full reconstruct the chain of events as they occurred this new find provides us with a little window into life and death among marine reptiles during the ancient past.

I don't remember a dinosaur in the nativity... From Flickr user tinkernoonoo

Every year there is a new “must have” Christmas toy that kids can’t do without, but dinosaurs never go out of style.  I am not just talking about the latest roaring, stomping, glow-in-the-dark action figure that will drive parents nuts, but a real dinosaur. I wanted one as a kid (ok, ok, I still would love a dinosaur for Christmas) and plenty of children still ask for them every year. From a list of letters to Santa printed in the Sand Mountain Reporter:

Dear Santa, I have been good this year. All I want for Christmas is a big dinosaur. I will leave you cookies and milk. Love, Ethan Barry

But whether there is a Microraptor, Stegosaurus, or some other dinosaur under the tree this year, we here at Dinosaur Tracking wish you and yours a warm, safe, and happy holiday. Merry Christmas!

We’ll return on Monday, December 28.