Monday, December 6, 2010

5 Questions for Scott Persons

A few weeks ago my friend and colleague Scott Persons published his first ever paper, detailing the results of the first phase of his Masters research at the University of Alberta. The paper received a fair amount of media and blog attention, but I demand attention as well, so here is a mini-interview with Scott  about the paper.

(But before we get started, you should check out Scott on Daily Planet, a very popular science variety show on Discovery Canada that I was shocked to learn is not carried by the American Discovery Channel. Tragedy!)
(Sadly, the frozen dissected lizard did not make the final cut for the segment.) 

1. What inspired you to conduct this study?

The inspiration to do a project on theropod tails came the summer before I began grad school in Edmonton. I was working at the Paleon Museum in Glenrock, Wyoming, and helping to put together a display case on the predatory dinosaurs of the Morrison Formation. Included in the display were two tail vertebrae. One from an Allosaurus and one from a Torvosaurus . . . and they looked really different! (For those of you interested, one major difference is the angle of the caudal ribs. In Torvosaurus the caudal ribs are strongly angled backwards, while the caudal ribs of Allosaurus are nearly perpendicular to the neural spines.) I asked the curator, Shawn Smith, about the differences, and he told me that no one really understood the functional significances. So, that got me thinking about tails, and this study was only the first part of a much larger project investigating theropod tail morphology and function.

2. What are some of your favourite Tyrannosaurus reconstructions?

That’s hard. T. rex is the most commonly depicted dinosaur, and a lot of paleo artists, from Charles Knight to James Gurney, have given us their renditions. Two of my favorites are John Gurche’s illustration of Sue and Michael Skrepnick’s “The ‘King’ prepares to defend his meal” (I’m not sure that’s the proper title). Not only do these depictions get the anatomy right (for the most part), but they succeed in conveying a visceral sense of power and menace. Recently, my favorite is Scott Hartman’s depiction of Stan, because it was created in collaboration with my study and really shows off the beefiness of the tail.

(Scott Hartman's excellent drawing can also be seen in Persons and Currie 2010 --Victoria)

3. Could Tyrannosaurus outrun the Jeep in Jurassic Park?

Well, that depends on how fast you think the Jeep was going. John Hutchinson and Stephen Gatesy have watched this cinematic sequence closely, and they concluded that the Jeep was traveling at over 40 mph (64 kph). No, I don’t think T. rex could go that fast.

But Jurassic Park was actually pretty specific about the T. rex’s intended top speed. Early in the film Richard Attenborough says to Sam Neill “Well, we’ve clocked the T. rex at 32 miles per hour.” Could a Tyrannosaurus do 32 mph (51.5 kph)? That would be about twice as fast as a modern elephant, but not much faster than a black rhinoceros (although maximum rhino speeds are hotly debated). I think it’s important to emphasize that my study only provides one of the many pieces of evidence needed to answer this question, and I think a lot of those pieces are still missing.

However, if we want to force the issue, and if I had to place a bet at the Dino Derby, I’d bet on “yes”. But (just to hedge my bet) the T. rex that I’d enter in the race would be a sub-adult. Young tyrannosaurs were lighter and had proportionately longer shins, so they were probably significantly faster than the bulkier adults.

4. How does this relate to the idea that Tyrannosaurus rex was a scavenger rather than a predator? This is an important and timely debate.

Your sarcasm is well founded. The scavenger vs. predator debate has largely been perpetuated by paleontologist Jack Horner, who is a vocal advocate for the scavenger hypothesis. But, in his book The Complete T. rex, Horner wrote “I’m not convinced T.rex was only scavenger, though I will say so sometimes just to be contrary and to get my colleagues arguing.” – p. 218. Add to this the recent discovery of hadrosaur tail vertebrae with healed tyrannosaur bite wounds, and it’s safe to say the debate over whether T. rex was purely a scavenger is basically over (if, indeed, it ever really existed).

But, if we let ourselves be provoked by this contrarian notion, the tail study’s results are relevant. If Tyrannosaurus was a scavenger, then the big theropod wouldn’t need a large M. caudofemoralis, because it doesn’t take much athleticism to catch a rotting corpse, and a slowpoke T. rex would have been poorly adapted to chase after live prey. So, if Tyrannosaurus had a small M. caudofemoralis and was incapable of rapid locomotion, this would support the scavenger hypothesis. As it turns out, T. rex had what it took to chase and catch dinosaurs like ceratopsians (the horned dinosaurs) and hadrosaurs (the duckbilled dinosaurs) while they were still alive.

[Note from Victoria: I myself have no problem with speculating on the feeding strategies of Tyrannosaurus. However, I knew that this would be what many media sources would jump on with regards to Scott's paper, even though it is not the most interesting aspect of the study, and was correct. So there.]

5. Will it blend?

As demonstrated by Dickson et al. (2007), everything blends . . . except Chuck Norris.

Lastly, Victoria, in case your readers aren’t aware, I’d like to point out how helpful and important your work on ankylosaur tails was to this study. The theropod tail project has built directly on the caudal muscle classification scheme outlined in your 2009 paper in PLoS One.

Well Scott, with that you can occupy the same office as me for the next few weeks at least, I'd say.

You can find Scott's paper online here (PDF not available just yet though, I'm afraid). Scott also did a great guest post over at Dave Hone's Archosaur Musings which is well worth a read.
And finally, Pete would like me to point out the amusing list of results if you google 'scott persons tyrannosaur'.

1 comment:

  1. Actually, my recommendation was that you search for, 'Scott Persons' junk in the trunk: