Dimetrodon Discovery! [VIDEO]

This morning, we were super-excited to see that the Houston Chronicle’s story about our paleontology team’s recent discovery of a Dimetrodon giganhomogenes made the front page!

Dimetrodon Found!

You can read the full story online, or check out the video below – the Chron’s fascinating interview from the site of the discovery with our curator of paleontology (and blogger!) Dr. Bob Bakker.

Can’t see the video? Click here to view.

See photos from the site on Flickr, and check back on the blog for updates from the team! And, get ready to see this apex predator in person when our new paleontology hall opens in 2012!

Discovery! HMNS Paleo Field Team Unearths Extremely Rare Dimetrodon

The Houston Museum of Natural Science Paleontology team has discovered an articulated specimen of a Dimetrodon on the Craddock Ranch in Baylor County!

The team named the fossil “Wet Willi”—“Wet” because it was found while excavating a drainage trench for the quarry, and “Willi” for Samuel Williston, a paleontologist and educator who was active at the site one hundred years ago. Dimetrodon bones are common in the Craddock quarry, but articulated fossil skeletons, like “Wet Willi,” are extremely rare. Most of the Dimetrodon fossils on display in museums across the country, and even globally, have come from this area of north central Texas.

Our Associate Curator of Paleontology Dave Temple shows what makes Wet Willi so special in this clip:

Can’t see the video? Click here to view it on Vimeo.

“Willi” represents a subspecies, Dimetrodon giganhomogenes, originally described by Paleontologist E.C. Case in 1907. The type of specimen he used for his description had no head; “Willi” is the first example of this species found with the head attached.

Wet Willi! New Dimetrodon Discovered by HMNS team
Get a load of those TEETH.
See the full set of photos from the site on Flickr.

In life, “Willi” was the dominant predator of his world, and he would have been 11 feet long with a four-foot vertical fin running the length of his body. The purpose of the prominent fin that defines this species has been debated since it was first discovered by Edward Cope in Texas in 1878. It was originally suggested that the fin was used for thermoregulation—self-regulation of body temperature, even when outside temperatures may vary drastically. However, it now seems more likely that this dramatic fin was for show—to intimidate enemies and fascinate potential mates.

“Wet Willi” will be the star of the Permian section of the Museum’s newly renovated paleontology hall, opening in 2012, and will serve as an ambassador from this geologic period for millions of patrons. The Permian ended with the worst mass extinction known, and was a direct precursor to the rise of dinosaurs. At present, the Museum has a mural of the Permian Period featuring a Dimetrodon, but no fossils on display.

Wet Willi! New Dimetrodon Discovered by HMNS team
See the full set of photos from the site on Flickr.

Over the past five years, HMNS field crews under the direction of Dr. Robert T. Bakker, paleontology curator for the Houston Museum of Natural Science, have collected hundreds of bones, teeth, and coprolites, as well as complete skeletons of the smaller reptiles and amphibians that lived alongside “Willi.”

“There is a very strong Texas connection to Dimetrodon, and we are thrilled to be able to display one in Houston, along with the other animals that made up this ancient ecosystem,” said Dr. Bakker, adding that the specimen is “jaw droppingly beautiful.”

Area ranchers agree; local cattleman Donald Coltharpe remarked, “The only thing prettier is a new born calf.”

Lucy’s Monstrous Misfits II: Upside-Down Mastodon

Dr. Bakker’s series on Lucy continues below. Check out  Part 1: Lucy – Out of Africa. Not! and Part 2: Lucy’s Monstrous Misfits: The Moose-Giraffe.

Why did some of Lucy’s neighbors score big bio-geographical successes, spreading over many continents?

Three More Cases: Hairy Monsters With Tusks & Trunks

Elephant bull 2
Creative Commons License photo credit:
Tambako the Jaguar (on the sea)

The Order Proboscidea includes all elephant and elephant kin – large to giant to super-giant herbivores with long upper lips transformed into trunks, plus long tusks. Tusks can sprout from the upper jaw or the lower jaw or both jaws.

Regular Short-Tusked Mastodons – “The Ohio Incognitum”

Regular Mastodons were the first fossil Proboscidea to be discovered – way back in the early 1700’s.  The legs looked like elephants’. The teeth looked like giant pig teeth.  Explorers in the Ohio Valley called the monster the “Unknown  Creature (Incognitum) from Ohio.” Formal name: Mammut.

By the late 1700’s full skeletons showed the whole beast – it was very like an elephant but shorter with a low forehead and short, stout upper tusks.  Lucy lived with Regular Mastodons who were very close to the Ohio Beast.

Regular Mastodons – The Long-Tuskers (Anancines)

DeinoAnancine copyLiving side by side with the Ohio Regulars in Lucy’s Africa was a close relative: The Long-Tusked Regulars. Technical name: the Anancine mastodons. In the Anancines, the super-long tusks stuck out so far we’d expect the beast to trip itself if it ran fast.

Upside Down Mastodon.

Now for the maximum weirdness among proboscideans: the Deinotheres.  Large to super large, Deinotheres had a long, long history in Africa, beginning way before Lucy or any other australopithecine. Body was elephantine – but the feet were small, with tiny side toes and three big ones in the middle.

The astonishing feature was the curved tusks. They were upside down. Instead of being in the upper jaw and curving up, the way they did in all normal mastodons, Deinothere tusks curved down and were in the lower jaw.

What good were upside-down tusks?

Old-timer scientists speculated:

“Maybe they hauled themselves out onto ice flows, like walruses do.”

Wrong. Deinotheres never lived in cold regions.

“Maybe they killed their prey with a downward jab.”

Wrong.  Deinothere molars were vegetable choppers, designed to munch big leaves and branches. All deinotheres were vegetarian.

“Maybe they used the tusks to cash down onto branches to break them off.”  “Maybe they fought each other in the mating season.”

Maybe.

World MapDeino

As global travelers, Deinotheres are intriguing. They were like hippos. Deinotheres spread over Europe and India and China. But they never conquered Siberia and never entered the New World, via the Bering Land Bridge.

Makes you think……

Why?

Butch Cassidy and the Sundance…Diplodocus

Elegance among Jurassic Giants.

It makes a profound impression – our Houston Diplodocus.

She’s a giant – ninety feet long.

b13_0010Diplodocus hayi, on display in the Hall of Paleontology
at the Houston Museum of Natural Science

But  she’s elegant – the neck curving forward in a graceful S-curve. The tail extending up and away from the hips. When you look from the balcony at our Diplodocus, her double-arched construction reminds you of the most beautifully-designed cantilever bridge across some wild Wyoming river.

Back in her day, the Late Jurassic, 150 million years ago, Diplodocus must have glided over the dry landscape with smooth, long strides. Here and there she would rear up on her strong hind legs, brace herself with her tail, and probe the upper branches of tall tree ferns and conifers.

dipapatcamoutline

She’s not the weightiest veggie-saur in her Jurassic world. Her close kin Apatosaurus would be twice as heavy. Her neighbor Brachiosaurus would be four times her bulk. But no other dinosaur can exceed our Diplodocus in the combination of length and delicacy of architecture.

I label our animal a “she” from an old tradition but, in fact, we don’t know the gender, yet.  Whether male or female, Diplodocus specimens also invoke another moniker – “Dippy.”

 And our Houston Dippy is very special. She’s “Utterback’s Dippy”, the skeleton that surprised the scientific world and made every museum change its displays.

The Veggie-saur Trio

dippyapatcam-copyDiplodocus is one of the Three Jurassic Amigos, the trio of long-necked giants who together make up 90% or more of the large dinosaurs in the American West during the final stages of the Period. The Camarasaurus is the most common. Its thin neck, of moderate length,  boxy head and long front legs contrast with the attenuated neck, pointed muzzle and short forelimbs of Diplodocus and the Apatosaurs. Apatosaurus itself matches the Dippy  proportions closely except that every bone is greater in girth.

Fossil guts tell us intimate secrets about Jurassic table manners. Camarasaurs have longer, deeper ribcages than do Dippies and Apatosaurs – that tells us that it had more voluminous intestines capable of digesting tougher, more fibrous plants. Diplodocus and Apatosaurs possessed surprisingly small guts. The ribcage was shorter front-to-back and shallower. With such reduced gut volume, these dinosaurs had to be selective in choosing the richer, more concentrated vegetables – young leaves, succulent branches, and reproductive parts.

camtail-copy

The trio all were unearthed in the two decades of the Great Jurassic Gold Rush, when eastern museums revealed the riches of the Jurassic fauna in Wyoming and Colorado. The first good Camarasaur skeleton was dug in 1877; the first good Apatosaur in 1879, and the first good Dippy in 1896.

You’ll find the Three Amigos mingled in Late Jurassic bone quarries with some other, less common “long-necks” (known technically as “sauropods”). Brachiosaurus is like an extreme Camarasaur. The ultra-thin neck is twice as long; the forelimbs far taller; the torso extraordinarily deep. Barosaurs are extreme Dippies, with the neck pulled out far forward and the torso even more abbreviated.

Andrew Carnegie’s Globe-Trotting Dippy

Andrew Carnegie, the multi-billionaire of the time, fell in love with Dippy skeletons dug in Wyoming by his Carnegie museum in Pittsburgh. Thanks to Carnegie’s cash,  precise replicas in plaster were given to all the great museums in Europe. The opening of the Dippy display in London drew immense crowds.

Soon there were Dippy posters, Dippy scale models, Dippy shaving mugs, Dippy dinner wear and all manner of Diplodocus bric-a-brac and souvenirs, some tackier than others. Diplodocus became the unofficial ambassador from the Jurassic Republic to the civilized world.

Among many other osseous marvels, the bony tail construction of the Dippy Clan was awesome. The scholars who studied the first good Dippy skeletons dug in the late 1890’s noted with admiration the strength and flexibility of the tail. “A weapon for sure – and a useful third leg for standing up in a tripod posture.”  The first twenty vertebrae coming out of the hips make a powerful tail-base. There are muscle prongs sticking sideways and downward and especially upward. In life, powerful muscles attached to these bone protuberances. All Dippies could swing the tail with bone-breaking energy sideways and downwards and up-and-sideways. So could Barosaurs and Apatosaurs. Camarasaurs, Brachiosaurs and other Jurassic long-necks were far weaker in this anatomical sector.

dippyup1904-copyCarnegie’s gift Diplodocus enthralled both the public and the anatomists at universities who scrutinized every limb bone, vertebrae and rib. But…..despite meticulous care in reconstruction, all of Carnegie’s Dippies had a built-in error, a mistake of prodigious dimension. The same mistake was carried in Apatosaur diagrams. The tail was much, much m u c h  too short.

It was an honest mistake. Carnegie Museum scientists estimated that the Dippy tail would come to a pointed end about fifty or sixty vertebrae from the hips. After all, that was the pattern in crocodiles and gators, living kin of the dinosaurs. Plus – most other giant dinos had similar specification – Stegosaurs, for instance, had strong anterior tails, built like a Dippy, and then the backbone in the tail got thinner and thinner and ended in a blunt point.

However……there were clues to a tail of unprecedented design. Quarries dug with Apatosaurs and Diplodocus in the 1870s & ‘80s gave some strange, thin, double-ended bones. Front and back were bulbous. The main body of the bones was a simple rod. What were these weird elements anyway?

1902 – Caudal Surprise in the Power River

Carnegie Museum men weren’t content with their first Dippy discovery, excavated in southern Wyoming at Sheep Creek. In 1902, they explored further north, into the wild badlands cut by the Red Fork of the Powder River. This was bandit country. Butch Cassidy and the Sundance Kid had their hideout nearby. Christened “Hole in the Wall,” the bandit camp was nestled deep in a winding canyon, overlooked by towering outcrops of red Jurassic rock.

In charge of the Red Fork expedition was the redoubtable W.H. Utterback.  Utterback was already so renowned at the Carnegie Museum that he had a Camarasaur-like dino named for him: Haplocanthosaurus utterbacki. Utterback knew what he was doing. In a week or two he found a superb Dippy. Part of the skull was there, and much of the shoulders, hips, hind legs, and feet – enough for another museum display.

And there was tail. Utterback dug out from the hip region and got a fine series of vertebrae. Ten, twenty, then thirty segments. The tail bones were getting thinner and thinner, just as they should if Utterback was nearing the pointed tail tip. But then – just where all the professors had said the tail should come to a point, it kept on going. Forty, fifty, sixty vertebrae, all exceptionally thin and simple.

Utterback was a hard man to surprise – he had seen so much in his career already. And yet the Red Fork tail was astonishing. It NEVER ended. He estimated that he was about eighty vertebrae from the hips when the bones stopped. However, there was a bulgy joint at the end of the last bone, so he figured there had to be even more. He was right. Subsequent finds showed that the Dippy tail went to eighty five or even ninety segments – a record for dinosaurs.

The Carnegie Museum technicians rushed retrofit kits to London and all other foreign cities that had received Dippy replicas. Plaster casts from the Red Fork tail were added to the displays – soon the world gasped at the caudal spectacular.

Apatosaurs and Barosaurs turned out to have the same tail ending. It certainly looked like a whip. A well-mounted Dippy skeleton seemed to be holding a gigantic bull-whip at its rear end. Modern day lizards and crocs do use their tails to lash out at enemies. Many a zoo keeper in the Reptile House had the scar on his leg from an iguana tail strike. Unwary naturalists had been knocked over by a bull gator tail blow.

Anti-Damage Joints

diplotailwhipAnd the construction of the Dippy whip seemed ideal for Jurassic martial arts. Tail joints usually are complex in dinosaurs. There are prongs and flanges for muscles and ligaments, holes and channels for arteries and the spinal cord. These bits of anatomy could be damaged if the tail were whacked vigorously.  The Dippy Clan had all these complexities in the front of their tails. But the whip-tail of Dippies was simplified to minimize the potential injury. Gone were the muscle and ligament prongs. Gone too were the arteries and nerves. Whip-Tail vertebrae were reduced to uncomplicated rods.

The strange bone-to-bone joints made sense in a whip context. Instead of ball-in-socket joints, the whip tail bones came together in a ball-on-ball joint. Both front and back ends of the whip-tail bones were bulgy, so a ring of cartilage must have been present to hold the bones together. Utterback had his crew recognized the unique possibilities: a Dippy tail tip could flex and bend in ay direction, faster than in any other known dinosaur family.

Tail damage couldn’t be prevented totally – most well preserved Dippy tails have one or two bones that had been broken then healed during life.

Tail-Targets

Who got whacked?  In the Late Jurassic, who was on the receiving end of tail-lashings?  Predators of course. Diplodocus and Apatosaurs were not defenseless mountains of quivering veggie-saur flesh. They could counterattack. A big predatory Allosaur would be only three tons or so,  a fifth the weight of a Dippy. If the predator crept close, hoping for a neck bite, the Dippy could reach out and whip the meat-eater when it was still forty feet away.

Long whips would be good for guarding Dippy babies as well. And there must have been whip-tail on whip-tail violence. Today, giant plant-eaters are a quarrelsome lot. Bull elephants spar with each other. Bull giraffes knock their heads sideways in neck-thrashing contests. Dominant females aren’t reluctant to fight either.

When Utterback took a break from digging, he’d rest under a cedar tree and imagined what his Dippie’s would have done, in the cool afternoons of the Jurassic.  I do the same at my quarries. I can see great herds of Dippies and Apatosaurs, with a sprinkling of Barosaurs – they left their footprints in massed numbers in Wyoming, baby tracks and adult tracks together.

And I see the long necks swing sideways with an occasional “clunk” as young adult males joust. Then the tail contests begin. “Whack-whack….whackity-WHACK!”  Dominant bulls and cows invoke their rank by hitting neighbors who get too close.

The Houston Dippy Who Taught The World About Whip-Tails

Whenever I pass through the Great Hall at our Houston Museum, I pause to look at the tail. It’s a wonder of Nature. And this specimen was the first to announce the existence of my favorite clan of veggie-saurs – the Whip-Tails.