Wyrex’s fancy footwork and tender hands: Get to know this tyrannosaur’s softer side

As we all know, Tyrannosaurus rex is the world’s No. 1 favorite dinosaur, so we at the Houston Museum of Natural Science are as pleased as punch over our specimen Wyrex, a truly splendid fossil that will help fill out the Cretaceous zone of the new Hall of Paleontology.

Wyrex will join our casts of Stan, an adult rex, and Bucky, a teenage Tyrannosaurus, in the new hall next week.

Bakker Wyrex Blog
Here’s our Wyrex sniffing at the trail of our duck-billed dinosaurs

Our Wyrex gets its name for Montana rancher Don Wyrick, who spotted bones eroding out of river sediments that were deposited about 66 million years ago during the Lancian Age — the last slice of dinosaur history before the great die-off.

Of course, T. rexes are famous for their bone-crushing bite and the old question of whether they were cowardly scavengers or fearless predators. But equally fascinating is the century-old puzzle of tyrannosaur digits. (Fingers, not phone numbers).

And that’s precisely why our Wyrex is a scientific groundbreaker. He has the best-preserved hands and feet of any T. rex ever uncovered, and he has something to say about three tyrannosaurian problems:

Theory No. 1: Some scientists say: T. rex was a waddling stumblebum, so slow that you could easily escape it at an amble.

Let’s look at the hard (fossilized) data.  Our database includes all the maxi-fauna today —  land creatures who grow to a ton or more. We find that slow walkers, like elephants, have short shins and very short ankles compared to their thigh length.  A charging African elephant, for example, hits 22 miles per hour. Faster large animals, such as rhinos (who get almost as heavy as elephants) are equipped with more length in shin and ankle. An angry white rhino easily surpasses 30 miles per hour.

Wyrex, in contrast, seems elegantly leggy — his shin and ankle are way, way longer compared to his thigh than the ratios we see in an elephant. Wyrex confirms what a dozen other T. rex skeletons have already told us: These giant dinos were built for speed. (Whether they were built for comfort, I’d guess no one was brave enough to find out.)

Bakker Wyrex Blog
A rhino, a fast big critter, next to a T. rex. Notice how long the shin and ankle are in the rex.

Here’s another way to test the slow-rex theory. Fast animals today — small, medium and large — have compact ankles. The long ankle bones, called “metapodials,” are tightly bound to each other so they make one strong unit. Slow walkers like elephants have loosely constructed metapodials that let the entire ankle spread out.  Check out our Wyrex’s ankle. Tight or loose?

TIGHT! There are three long ankle bones, and the inner and outer bones hug the middle bone so tightly that the whole ankle works as one bony unit. That is not an elephant-style spreading foot.

Our three rexes, Stan, Bucky and Wyrex, tell us most emphatically that their species were not slowpokes.

Theory No. 2:  Some scientists say that T. rex fingers were powerful meat hooks.

Wyrex’s hand is worth pondering. In the new hall you’ll be able to stand very close to the bones, so you can compare your arm and fingers to his. At first glance, the rex mitt does seem as strong as a grizzly bear’s. But wait … in nature, what matters is how strong your hand is compared to the rest of your body. Wyrex was 10 times as heavy as the average grizzly bear. That means the Wyrex arm is 10 times weaker relative to his body weight than the bear’s.

When we diagram a grizzly bear with the the proportions of Wyrex, the poor bear seems to have a ridiculously wussy arm:

Bakker Wyrex Blog
Check out the measly arms on this Grizzly bear proportioned like our Wyrex.

Now analyze the Wyrex claws. Are they as big and hooked as hand claws from earlier meat-eating dinos? Nope. Our Acro (Acrocanthosaurus) is a bit smaller in body weight than Wyrex but has much heavier, sharper and more hooked claws.  T. rex evolved from an ancestor shaped like Acrocanthosaurus, who evolved from something like the Jurassic megalosaurs. If claw strength really was important, why did evolution make the rex claws weaker?

Then there’s the famous two-fingered salute. Most dino carnivores had three strong fingers — thumb, index finger and middle finger. Allosaurs from the Jurassic are built that way, and so are the acrocanthosaurs from the Early Cretaceous. So are all the raptors. One example? Our cast of Deinonychus, the raptor who inspired Jurassic Park.

Wyrex has a near-perfect hand. But how many fingers does he have? Two — thumb and index. And the finger bones are far skinnier than what you see in an allosaur or an acro. All T. rexes and their close cousins, the gorgosaurs, were weakly two-fingered.

Bakker Wyrex Blog
A rex arm next to a Jurassic meat-eating megalosaur.

How and why did evolution clip off that third finger? Wyrex shows us. Stare at the outer side of the hand. You’ll see an ultra-thin bone crowded against the index finger. That’s a remnant of the third digit. It was retained because some major muscles attach to the base of the third finger, muscles that are needed to rotate the whole hand sideways.  Other rex specimens probably also had that remnant of the third finger, but lost the bone after death when scavengers nibbled away the muscles.

third finger
The thin remnant of Wyrex’s third finger

The muscle-attachment on the finger remnant tells us that some sideways movement was still important in Wyrex, but it was a delicate movement — not the brute action of a meat-hook.

Theory No. 3: In 1905 one famous scientist theorized that rex fingers were for gentle…tickling!?

It sounds weird at first. However, that scientist was none other than Professor Henry Fairfield Osborn, the New York paleontologist who found the first T. rex and gave the species its name. Osborn had great insights into extinct animals. He had museum-smarts AND zoo-smarts.  He was on the board of the Bronx Zoo, and he observed live animals. He knew that a giant predator needed more than powerful jaws for killing prey and long limbs for chasing it; predators needed a way to attract desirable mates so they could make healthy, desirable offspring.

The problem: If you are a 10,000-pound rex who can bite another dinosaur in half in one chomp, how do you express tender, romantic feelings?

The answer: Tickling. Many animals today use a small finger or toe to stroke their loved ones. Critters with fur or feathers spend much time grooming their friends and mates with delicate strokes of claw-tips. Grooming renews the bond between male and female, between parent and youngster, and between pack-mates in a hunting group.

It is a fun fantasy. Think of it: a young mated couple of rexes relaxing after a meal of duck-bill meat, stroking each other’s necks and muzzles, then petting their newly hatched chicks.

The fantasy becomes more believable if rexes had fur or feathers. Feathers have been found with many small and medium-sized meat-eating dinos, but up until 2012 no one had excavated a big tyrannosaur with feathery pelage.

But in the spring of that year, our Chinese colleagues announced an Early Cretaceous tyrannosaur fossilized with big sections of skin.  In the skin were tightly packed feathers — thin, kiwi-like feathers — up to a foot and a half long. The Chinese species was very similar to what the direct ancestor of later tyrannosaurs must have looked like.  The conclusion, then, is that Wyrex, too, probably had feathers.

So recent discoveries back up what Professor Osborn said over a century ago: T. rexes had a softer side — literally!

An aside — Osborn was not only a superb research scientist, but also a brilliant designer of public exhibits. He was the first to mix skeletons with beautiful murals and sculptures of the extinct beasts in their natural habitat. And he envisioned a fossil exhibition as a series of safaris back into deep time.

In other words, Osborn would have loved our new HMNS Hall of Paleontology — and you will, too.

Black Hills Institute

Today’s post is by Sami Mesarwi, a member of the Museum’s marketing staff who recently traveled to South Dakota to visit the Black Hills Institute. 

If the company you work for had to send you on a business trip anywhere you wanted to go, where would it be?  Paris?  London?  Shanghai?  How about Hill City, South Dakota?  Probably wouldn’t be a first choice for too many out there… And while I would have said the same before my trip to the Black Hills Institute of Geologic Research (and I probably still wouldn’t be able to pass on Paris), this paleontological-Mecca should definitely be in the running for you dino-die-hards out there.

Black Hills Institute Outside Facade
The Black Hills Institute of Geological Research

I’ve always loved dinosaurs. 

In fact, Michael Crichton’s Jurassic Park is still one of my all-time favorite books (I may have grown up thinking that Crichton’s logic used in the novel to try and resurrect dinosaurs using the DNA found in preserved mosquitoes, as well as amphibians to fill in the holes, was flawless, but I’ve come a long way since then).  So, going on this trip seemed like it was going to be quite enjoyable from the start.  Our mission was simple enough: to go up and get some photos of the fossils that will eventually be on display in the museum’s upcoming new paleontology hall, opening summer 2012.

A coworker and I took the trip up to South Dakota in April, a time when Houston weather had consistently already warmed up to 90+ degrees outside.  However, surprising to all of us on the trip, we were greeted by snow in South Dakota!  Even though it was April, it was a Winter Wonderland—the color of the snow that covered the ground literally blended in with the sky’s horizon. Needless to say, it was pretty cold.  But I was able to get some pretty nice still shots out of it.

Winter Wonderland
Winter Wonderland!

Day one of our trip to South Dakota was a whirlwind of sights and sounds from within the Black Hills Institute. 

Everyone met up inside the Institute with the famed Peter Larson, the Yoda (though not quite as old) of casting fossils and of T. rex.  He gave us a brief history of his background and of the Institute while in the main lobby area, a who’s who of dinosaurs from several different eras.  In addition to the infamous SUE the T. rex, there were examples of Triceratops, Struthiomimus, Acrocanthosaurus, what seemed like an infinite amount of ammonites, and so much more, all filling an area about the size of an average backyard in the suburbs.  It was amazing—I’ve never seen so many dinosaurs in a compact area before.

Pete Larson
Pete Larson in the zone.
Dino Showroom
The Black Hills Institute Showroom

Onwards we continued to the prepping areas (a separate building from the museum itself), showcasing a few dinosaurs in the development and mounting stages. Pete told us about several of the specimens we’d be getting here at HMNS, before all of the paleontologists on hand broke into a discussion about the immaculate condition some of the fossils were in (I can’t give away too much about what in particular we’re getting—you’ll just have to wait and see!).  Before this trip, I thought I could hold my ground pretty decently well in matters of dino-speak.  But boy was I wrong.  Being surrounded by so many accomplished and literally world-renowned paleontologists (including Pete Larson, Dr. Robert Bakker, and so many others) was really very exciting.  But also quite humbling.

Pete then took us to the casting/molding area, where several Black Hills employees were diligently working to create some very impressive casts of fossils that they had.  They poured the liquid silicone rubber into the two mold halves, and, with some of the smaller ones, fastened them together with—interestingly enough—Legos! Turns out those colorful, little building blocks aren’t just fun to play with, but are also way more practical than you would think…

Pete Larson Bob Bakker
Pete Larson and Dr. Bob Bakker examining a recent find.

Our second (and final) day of the trip allowed for us to talk up close with Pete himself. 

Pete told us all about the Black Hills Institute itself and how it came to be—in 1974, as an earth science supply house, providing teaching specimens for colleges and universities, before branching out into doing museum exhibits.  In fact, as Pete points out, the products coming out of the Black Hills Institute can be found on every continent in the world (though he was mindful to exclude Antarctica from the list—hardly as impressive now, if you ask me).  After he answered our countless questions, Pete allowed for us to roam around the Black Hills Institute at our leisure, getting some shots of whatever it is that we wanted.  We took still shots of some of the specimens that will be making an appearance in the new paleontology hall, as well as some of the stars of the show.

After that, we grabbed a quick lunch at the corner bistro before heading back home to Houston.  Though we did make a quick stop on the way back… As we were only about 15 miles away from Mount Rushmore, we went ahead and visited the famed monument on our way to the airport. Quite breathtaking, I must say!  To me, the tranquility of the park where the monument is located, coupled with the remarkable stature of the presidents whose faces are forever immortalized in the mountain’s façade, were equally as impressive to me as the mountain goat we saw.

Mt. Rushmore
Mount Rushmore.

All in all, the trip to Hill City, South Dakota was so much cooler (both, literally and figuratively) than I originally anticipated.  While the city itself isn’t exactly the largest out there (population: 948), or the most exotic of your travel destinations, it should absolutely be a front-runner for all of you dino-enthusiasts out there.

Ankylosaurs aren’t very aerodynamic*

But they can still fly!

Ankylosaur Flying! [1.21.11]
Quite a view! See the entire set from the move on Flickr.

If you’ve never seen a dinosaur fly, then you weren’t in the vicinity of the museum around 11 am last Friday – at which time it was almost impossible to miss our airborne ankylosaur.

Pretty cool! The ankylosaur – an original created for the 1964 World’s Fair – has been a much loved part of our paleontology hall for decades. As part of the ongoing construction associated with our current expansion, the ankylosaur – along with several other displays from the hall – was de-installed and will be stored until it re-emerges in our new paleo hall in 2012!

Carolyn recorded this video – it’s amazing how fast this big guy hopscotched over our entire new wing!

More on the Ankylosaur!

HMNS Flickr Set“Warwick Towers Survive Dinosaur Attack” on Swamplot | Flickr set from allison362

*Excellent point, via twitter from @laelaps

Archimedes, Atoms and Archaeopteryx

Peter L. Larson, paleontologist and geologist, is a paleontologist and the president of Black Hills Institute of Geological Research in Hill City, South Dakota. Larson is on the research team investigating Archaeopteryx and other fossils at the SLAC National Accelerator Laboratory. Today he blogs about the fossil Archaeopteryx and how high powered X-rays helps us learn new things about this unique fossil.

  
Paleontologist. Pete Larson (left) at the SLAC National Accelerator Laboratory.

The discovery, sale and subsequent scientific examination of the sole surviving thousand year old palimpsest recording the work of Archimedes (who died in 212 B.C.) has made it possible to study fossils using high energy x-rays to map the distribution of elements across the surface of the rocks containing their remains. A group of scientists gathered at the Stanford Synchrotron Laboratory in Menlo Park California to study one of the iconic “missing links” of evolutionary biology, Archaeopteryx. This investigation was able to show that not only was there original material from the living Archaeopteryx preserved in the dino-bird skeleton, but that the “feather impressions” were not impressions of feathers, but the feathers themselves, preserved in the limestone matrix for more than 145 million years. This research has opened a door to a new dimension for the study of fossils. It gives us a new way to study soft tissue, the chemistry of preservation, and details that everyone thought were lost in time.

For details about the X-ray Fluorescence imaging of the Thermopolis specimen of Archaeopteryx, see the May 10, 2010 issue of the Proceedings of the National Academy of Sciences.

Take a tour of our current Archaeopteryx: Icon of Evolution exhibit with Pete in the video below, and don’t miss your opportunity to ask him questions during our upcoming online webinar session. Join us on June 17 at 10 a.m. as Larson answers questions about Archaeopteryx, the exhibition and his own research. Register here, or see instructions below.

Archaeopteryx: Tour the Exhibit with Pete Larson from HMNS on Vimeo.

To register for our online webinar with Pete Larson
1)      Click here.
2)      Click “Register.”
3)      On the registration form, enter your information and then click “Submit.”