Fossils for Profit

Yesterday, I wrote about a story questioning the identity of the small early Cretaceous tyrannosaur Raptorex, described about a year ago in Science by Paul Sereno. Peter Larson of the Black Hills Institute is of the opinion that Raptorex is considerably younger geologically, and that it's a juvenile Tarbosaurus, having come from Mongolia instead of the Yixian formation of northern China as Sereno originally proposed.


Raptorex kreigsteini restoration copyright Matt Martyniuk. From Deviantart.

The reason this is in question at all is that Raptorex was collected by a private party, and the only evidence of its original locality is from the testimony of fossil dealers and collectors and interpretation of the matrix in which the bones were preserved. As Ville Sinkkonen pointed out to me in the comments, the evidence for this locality is not a slam dunk.. When I wrote that the paper isn't "wishy washy" about the fossil's origin, I was referring to the fact that it puts one out there, including approximate longitude and latitude. How strongly does Sereno stand by it, I wonder?

There's nothing Sereno et al can say to definitively place Raptorex in the lowest Yixian, because they didn't collect it. I respect Sereno's talents and see the tough spot he was placed in when he gained access to the fossil: should it be ignored? And I'm sure he tried his hardest to pin point where it came from. But we can't be sure, and it's a cloud over Raptorex's head. This is where new research needs to be trained; I'm certainly not schooled enough in paleoecology to be able to weigh the evidence myself. Is Raptorex a key insight into early Cretaceous tyrannosaur evolution? Or is it just a baby Tarbosaurus? I really hope we can find out one day.

Today, you may be aware, is National Fossil Day. I'm not going to go into it too much here, as I've already posted about its potential at Under Indiana. But as I wrote that post, I thought about what a perversion of science the fossils-for-profit market is, and it just does not add up (mind you, I'm mainly speaking of big, flashy fossils, and not things like crinoid fragments and shark teeth). For it to work, you need two parties. One, collectors who are wealthy enough to purchase showy fossils and, possibly, conversant enough in natural history to be aware of their significance. Two, you need the folks who know enough to find them, excavate them, identify them, prep them, and sell them.

Granted, this is simplified, but my main point is this: these people should know better. If you're educated enough in science to see the value of a fossil, you're educated enough to know that its value to science far outweighs its monetary value and whatever prestige one obtains by owning and displaying it. Once it's been ripped from the Earth and passed around, the scientific value is virtually nullified.

Someone might say, "What's the big deal? I just bought an Allosaurus! Science has plenty of those!" And we might, but technology continually improves, and because of that there may be new information to pull from the bones in the future. The vagaries of fossilization my have preserved some quirky feature of the Allosaurus in the foyer, but if it's off limits to science, it may never be found.

Would I love to have some gorgeous theropod mounted in my house? Sure. But to me at least, giving something valuable to science is immeasurably greater. To each his own, I guess.

Raptorex: When it Lived and Where it Lived

A little over a year ago, Paul Sereno made a splash when he published the description of Raptorex kreigsteini, the small tyrannosaurid that looks for all the world like a perfectly scaled down version of the giants of the late Cretaceous, complete with disproportionately small arms. But it was from the early Cretaceous, opening up interesting new paths of inquiry into the evolution of the iconic group.

Yesterday, NatureNews ran a story written by Zoë Corbyn focusing on the doubts of Peter Larson of the Black Hills Institute. His concern: Raptorex is a juvenile Tarbosaurus. He steps around the objection that Raptorex is far to old, geologically, to be a young specimen of Tarbosaurus by proposing that Sereno had the age wrong. The NatureNews story says:

On the basis of two other fossils — a fish vertebra and a freshwater clam — found alongside the dinosaur fossil, the paper says that the specimen of Raptorex is of Chinese origin and about 125 million years old. But the evidence is too vague, given that the fish and clam fossils are widespread in time and geographic area...

You may recall that Raptorex was given its specific name to honor the father of the fossil collector who purchased the fossils and donated them to science. When Henry Kreigstein bought the bones from a dealer operating out of Japan, he was told that they came from an "unspecified location in northern China."

Sereno et al's Science report of a year ago is more specific than that, saying that it came from:

Approximately 41°20′N and 119°40′E, collected privately in the border area between Liaoning Province and the Nei Mongol Autonomous Region of the People’s Republic of China.

The purported Raptorex locality, indicated by the marker. Image from Google Maps.

The rock it was found in is described like so:

Lujiatun Beds of the Yixian Formation, comprising a tuffaceous fluvial facies of the Jehol Group with its well-known Jehol Biota that includes the teleost Lycoptera and pelecypods, which were found in association with the holotypic skeleton. The matrix around the fossil is light green, massive, poorly sorted, tuffaceous, micaceous sandstone with fibrous gypsum. The light-colored, uncrushed bones were buried for the most part in articulation. The absence of laminated, fine-grained sediment or conchostracans characterizes the Lujiatun Beds of the Yixian Formation, dated to the late Early Cretaceous (Barremian-Aptian, ~125 Ma).

So, to translate: Sereno's paper puts forth that Raptorex lived at the earliest stage of the Jehol Biota, a famous Chinese ecosystem that has yielded a bunch of interesting animals. It was a river system that experienced periods of volcanic activity. The Raptorex fossils were discovered with fish and mollusks which are well-known part of that ecosystem. Raptorex was also articulated, meaning its bones were preserved in roughly in the same position they would have been when the animal died, and it was likely buried quickly. That Raptorex was buried in a river or stream, and not a calm body of water is evident in the structure of the rock surrounding the fossil, which isn't laminated, or finely layered, and lacks fossils of the ubiquitous crustaceans called conchostracans, which occur in still waters. This is consistent with the rock of the Lujiatun beds, our earliest window into the Jehol ecosystem.

Sereno's paper isn't wishy-washy on the subject of where Raptorex came from. (See comments below for more on this) Yet Corbyn writes, "Sereno says that the information he received from the various dealers stated that the fossil came from an unspecified location in northern China."

I have couple other problems with this story. First, it's not reporting a published research paper. It's reporting the fact that one guy, a tyrannosaur expert though he may be, doubts the identity of this dinosaur. Cool. Let's see a published paper about it. It also brings in University of Oslo paleontologist Jørn Hurum to back up Larson's claim, but his contribution amounts to "yeah, it looks like a baby Tarbosaurus skull to me." None of this addresses the fact that the skeleton of Raptorex exhibits signs of being that of a near-mature animal, and not a juvenile. A near-mature animal the size of a large dog. Tarbosaurus was just a smidge smaller than T. rex. If Raptorex is actually a young Tarbosaurus, it would have to go through the mother of all growth spurts right at the cusp of adulthood.

I don't really care if Raptorex isn't exactly what Sereno's paper purports it to be. It's an intriguing additon to the story of tyrannosaur evolution, but if it's been misinterpreted, so be it. No one's perfect. But we need a peer-reviewed paper to really evaluate Larson's ideas. We need a detailed analysis of the rock in which its fossils were preserved and another look at its osteology.

The fact that Kreigstein rescued Raptorex for science is commendable, but the fact that the fossil trade has muddied the origin of these fossils is, to put it mildly, yucky. I'll continue with this aspect of the story tomorrow. In the meantime, if I've gotten any part of this complicated story wrong here, be sure to correct me in the comments or by email.

The Earliest Tyrannosaur

Since the tyrant lizards have been in the news so much lately, I figured I'd write a bit on our best known of the early tyrannosaurs, a beast discovered in Late Jurassic rock in China and named Guanlong. The other Jurassic tyrannosaurs are not nearly as well known. We have two relatively complete Guanlong specimens, an adult and a juvenile. While many tyrannosaurs feature head ornamentation of some sort - bumps, spikes, or small crests, Guanlong's head bore a large, delicate crest which in profile looks somewhat like that of Dilophosaurus.

Like the early Cretaceous Chinese tyrannosaur Dilong, it's likely that Guanlong was covered, at least partially, in hairy "proto-feathers." These would have been for warmth and display purposes, and the later giants of the family show no evidence of them, and would not have needed them to maintain their temperature as their large size would have done that job just fine. Both Guanlong and Dilong had three fingers; recently described Raptorex is the earliest tyrannosaur to bear the distinctive two-fingered hand.

National Geographic published a nice article on Guanlong in July of 2008, and the site also features a gallery dedicated to the fossilized mud trap where Guanlong was discovered with a whole mess of tasty fossils.


Drawing by Renato Santos.

More Raptorex

Catching up on NPR's Science Friday and ran across a segment on Raptorex featuring an interview with Paul Sereno, or as Ira Flatow calls him in a typically graceful introduction, "Paul Salerno." He also repeatedly calls Raptorex a "tiny T. rex." Is it so hard to understand that the word tyrannosaur is a perfectly acceptable generic name for the whole family? That way, you don't drive nit-pickers completely crazy.

I loved Sereno's response to Flatow's question about whether Raptorex is a missing link, too. "I cringe when I hear the words missing link."

Sereno also drops a little teaser that he's got another find he'll be revealing in coming months that will also be changing perceptions of dinosaur evolution. Can't wait to see what that is.

Raptorex, Raptorex

Whoa! News outlets and the paleoblogosphere have blowed up mightily over last 24 hours with the news of the new tyrannosaurid Raptorex kriegsteini. Brian Switek wrote a thorough description at Dinosaur Tracking. Chinleana's Bill Parker took a detour from his Triassic stomping grounds to mention it. At DinoGoss, Matt Martyniuk poked fun at its silly name. Beyond the dino-blog world, Jerry Coyne wrote it up on Why Evolution Is True and PZ Myers nodded his head Raptorex's way at Pharyngula. Sports Illustrated hasn't commented on it yet, but the NFL season just started, and there's that NL wild card race to keep an eye on--their plate is pretty full.

Raptorex by Todd Marshall

There's a reason Paul Sereno and his team at the University of Chicago picked a name like "Raptorex," and it was to garner the kind of immediate sensation that causes CNN.com to feature the story on its front page, as it did yesterday. Like the name or not - it strikes me a bit Saturday-Morning-Cartoony - it certainly caused a splash, and in a much more tasteful way than the Ida debacle. So what is the big deal about what appears, on the surface, to simply be another small, basal tyrannosaurid from the early Cretaceous?

Raptorex, as noted by Sereno, is almost exactly proportioned like its late Cretaceous relative, Tyrannosaurus rex. Unlike other early tyrannosaurids found in China, Dilong and Guanlong, Raptorex bears the signature stubby, two-fingered arms that have been amusing us since the discovery of T. rex. Previously thought to be a later development, this indicates that it was an adaptation that had use for small predators as well as the giant tyrannosaurids to come.

PS. It helps if you sing the title of this post to tune of "Birthday Sex" by Jeremih. Weird Al, you have your marching orders. Hop to.