Dispatches From South Dakota: Willie The Dimetrodon [Day 4]

Today’s post is from Michele Whisenhunt, a volunteer on the Museum’s paleontology team. She’ll be sharing photos with us while the team is at the Black Hills Institute, prepping Willie, the Dimetrodon the team discovered. Missed the team’s first dispatches? Day 1, Day 2 and Day 3

All work and no fun makes for a dull paleo preparer, soooo Mary Anderson, Pat Greenfield and I headed out early this beautiful morning for Custer State Park and a 14 mile drive where the buffalo and the pronghorn play. Autumn has hit in the Black Hills but the wildlife was worth the drive not to mention a glorious day. South Dakota is beautiful in so many ways.

Buffalo on the range

Arriving early afternoon for prep work at the BHI our direction turned to beginning the bone cleaning under Dr. Bakker’s direction and the microscope.

Precise fossil cleaning

After experimenting different methods of cleaning, a recipe was found. A vinegar bath gave the desired results.

Willie's leg
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Bernt under the magnified visor uncovers and cleans the most compete lower jaw of the Judy block, Trimerorhachis or Panzer Mudpuppy.

Jawbone

Tomorrow will be the beginning of many days prepping thousands of bones to complete Dimetrodon for his 2012 premiere in the new paleo hall.

Dispatches From South Dakota: Willie The Dimetrodon [Day 3]

Today’s post is from Michele Whisenhunt, a volunteer on the Museum’s paleontology team. She’ll be sharing photos with us while the team is at the Black Hills Institute, prepping Willie, the Dimetrodon the team discovered. Missed the team’s first dispatches? Day 1 and Day 2

It’s a beautiful and busy day in the neighborhood of Hill City, South Dakota

When we arrive to the prep lab there is activity everywhere with the Black Hills employees working on our new saber tooth cats, Xenosmilus and Smiledon some of the most fearless to roam. It is interesting to work side by side with the best in their field specializing in the finest fossils and fossil replicas.

Dr. Bakker instructs Mary Anderson, after finding the floating rib, to clean the rib bone and she uncovers a bite mark. Hallelujah, hallelujah! Everyone gathers to see the bite under the microscope.

Uncovered Bite Mark
Uncovered Bite Mark.

Kathy Zoehfeld has uncovered unknown rib in her skull jacket and she will continue working to uncover the pieces of skull.

Bernt Pettersson and Pat Greenfield faithfully work on the Judy Block, a huge Trimerorhachis block, named after the owner Judy, with Bernt uncovering a jaw with skin inside the lower jaw.

Marce Stayer and I are carefully pulling anterior and posterior spines. We’ll keep you posted daily as the work progresses.

Dispatches From South Dakota: Willie The Dimetrodon [Day 2]

Today’s post is from Michele Whisenhunt, a volunteer on the Museum’s paleontology team. She’ll be sharing photos with us while the team is at the Black Hills Institute, prepping Willie, the Dimetrodon the team discovered. Missed the team’s first dispatch from the field? Check it out!

While excavating Willie, the HMNS paleo team also discovered several small pockets of unidentified bones.  They were jacketed and sent along with Willie to the Black Hills Institute. 

Dr. Bakker inspecting Willie
Dr. Bakker inspecting Willie.

Today, volunteers Mary Anderson and Kathy Zoehfeld were each given one of these small presents to open.  Dr. Bakker was fairly sure Kathy’s jacket held a Secodontosaurus jaw.  A Secodontosaurus is a Permian Pelycosaur. He has a fin like Willie, but is smaller in size.  He has a longer snout and a narrower skull than Willie as well.

Kathy carefully started digging into her jacket, unsure exactly where this delicate jaw was located.  Layer by layer she picked away at the rock matrix, finding nothing.  Finally she found the tip of the jaw, then the first few teeth. 

Fossil Prep Work
Kathy doing some fossil prep work in the lab.

Unlike Kathy’s jacket, Mary’s jacket was a complete unknown.  The jacket was labeled “Willie’s feet”, but Dr. Bakker did not remember anyone finding Dimetrodon feet.  Mary started digging…and digging…and digging.  We started joking that the team had made an empty jacket as a joke.  And she kept digging…FINALLY, she found bone!  She called Dr. Bakker over.  He looked at the edge of bone and suddenly burst out OH! OH! I don’t know….She kept exposing more bone and then Dr. Bakker knew…it was not even close to being Willie’s feet—it was a Secodontosaurus vertebrae and neural spine.  A match to Kathy’s animal?  We will have to wait and see.

Willie's Let in a Jacket
One of Willie’s feet? 

Jurassic Puckering – Kissing Fish and Salt Water Evolution

Our Archaeopteryx show has bedazzling fossils – the only Archaeopteryx skeleton in the New World, complete with clear impressions of feathers. Plus frog-mouthed pterodactyls, fast-swimming Sea Crocs, and slinky land lizards.

But wait…….there’s more!

The exhibit has spectacular Jurassic fish!

By “spectacular” I don’t mean gigantic. Most of the Jurassic finny species were small to mid-sized, salmon to tuna in bulk. The extraordinary thing about our Jurassic fish is that the fossils capture the single most dramatic moment in all of fishy evolution….

….The Teleost Takeover!!
Teleosts are the unrivaled Rulers of Fish-Dom. Teleosts make up three-quarters of today’s fish species. When you eat fish, chances are you’re eating teleosts: tuna are teleosts, and so are mahi-mahi, swordfish, bluefish, salmon, red snappers, trout, bass, eels, herring and anchovies…

Gefilte Fish?  Yep. Teleost. So are white fish, smoked or non-smoked. Sail fish, tarpon, guppies…..

Teleosts belong to the “Bony Fish Clan,” one of the two huge branches on the fish family tree. The other big branch is for sharks, rays and skates

Pucker Faces
What makes teleosts so great? Pucker skulls. Go to an aquarium or a really big fish store. Watch the feeding. Teleosts protrude their faces, pushing out the jaw bones so the mouth cavity expands. Water rushes in, carrying food. Large mouth bass expand their mouths so wide they can suck in an entire duck.

Teleosts can use their pucker faces to reach out and nibble. Parrot fish do that when they gnaw away coral polyps. Catfish use their suction-mouths to vacuum worms from a muddy bottom. Remoras use their pucker-sucker mouths to get a free ride from a big shark.

Ok – all fish anatomists (people who dissect fish, not guppies who get PhD’s) agree: the pucker-swing-out, expanded face & jaws is the key innovation that opens the door to thousands of potential ecological niches.

Pucker Free Times
It wasn’t always so. The first bony fish comes in at about 400 million years ago. For the next 200 million years, there was no puckering. Jaw bones were firmly attached to the rest of the skull. Today, we have one Texas fish that still is no-pucker – the garfish. It grabs prey the way a gator does, with a simple snap.

First Tentative Pucker
In Triassic times, about 220 million years ago, some bony fish evolved a semi-moveable set of jaw bones that let the mouth expand sideways. Bowfins today are at this stage of evolution. Our Jurassic fish show has some nifty bowfin fossils.

Teleost Shock Troops
Bowfins didn’t go far enough. In the Late Triassic and Jurassic the first teleosts evolved. Face and jaw bones became mobile. Sucker-pucker faces started to diversify. That’s just the stage we catch in our Archaeopteryx display. The Late Jurassic lagoon beds from Solnhofen, Germany, abound with this first wave of teleosts. Don’t take my word for it. Come close to the glass cases with Thrissops, Pholidophorus and other early teleosts. Check out the jaws.

Teleosts would continue to expand into the next Period, the Cretaceous, and the through the following Age of Mammals.

so…..come to the Archaeopteryx show for the feathers…stay for the fish-faces.