How To Stuff Your Archaeopteryx For Thanksgiving

Serves 1/20th of a person.

You must become pubis-savvy to understand Archaeopteryx. The pubic bone commands the guts – and gut evolution was huge in bird origins.

1) Check out an allosaur, a typical big meat-eating dinosaur. Note that the pubic bone points down. This position limits the size of the guts because the intestines must stop in front of the pubis.

2) Check out a chicken, a typical modern bird. The pubis has been pulled way back so it points backwards. Now the guts can expand all the way to the rear of the bird.*

3) Now examine Archaeopteryx. If it were a typical bird with a big gut, the pubis should point backward. It doesn’t. It points down, like in an allosaur.

4) So……Archaeopteryx was a gut-less wonder, compared to a modern bird. The space for the intestines was still small. It couldn’t digest food as fast as a modern bird can and it couldn’t digest tough food items.

5) Modern-style bird guts didn’t evolve until the Cretaceous.

* that’s why we can stuff a bird with so much stuffing on Thanksgiving.

How To Get Your T.rex to Perch on Your Finger
Evolution of the Back-Grabber Toe in Birds

Here is our Archaeopteryx hind foot. Note that it’s got a “back-grabber toe,” an inner toe that points inwards and a little backwards.

Modern birds usually have an even bigger back-grabber toe that points further backwards. This inner toe lets the bird grab a branch or a finger and hold on.

(The toe is equivalent to our human big toe).

The other three toes in Archaeopteryx point forward and attach to three long ankle bones that are bound together tightly by ligaments. The inner toe has just a stub of an ankle bone.

Anchisaurus

Look at a primitive dinosaur, like Anchisaurus. No back-grabber. Instead the inner toe is thick and long and points forward. The toes attach to four long ankle bones that are loose and can spread.

Here’s the key step:

Meat-eating dinosaurs evolved an inner toe that pointed inwards – like a bird’s. Its ankle bone is a stub – just like a bird’s.

The three main toes have ankle bones tightly bound together – like birds’.

Raptor-type dinosaurs were even more bird-like, with thin, long ankle bones.

Archaeopteryx evolved from a raptor-type dinosaur by enlargement of the inner toe.

Hittin’ the road with the HMNS Paleo crew!

BB describing boomerhead

I got the chance to travel from Houston to Seymour, TX and explore the Texas Redbeds in search of fossils with David and the HMNS Paleo Program. HMNS staff and volunteers have been making these trips for four years now. They have found several excellent specimens and brought them here to prepare for our new and improved Paleontology Hall. I’d had some experience looking at the bones and things that the crew had been bringing back to the Museum but this was my first experience actually in the field – and I was pretty excited!

Drawing of a Diplocaulus

The first morning we arrived at the site and looked around at a few different locations before settling down in the “pit” to dig. I got to spend a little time training my eyes to see fossilized bone, teeth, cartilage and coprolites among the rocks at the “spoil pile” which is a great experience because the ratio of fossils to rocks on the surface is such that you have a pretty good chance of closing your eyes and picking up a fossil! Then we moved over to learn the digging technique where fossils were a bit more hidden in the pit; it took a few minutes to get the hang of how to hold the tools and make sure that you are using enough force to move the dirt but not so much that you break a hidden bone. All and all it was really enjoyable first day at the site.

Over the next two days after Dr. Bakker arrived we visited several other sites on the property and I got a chance to work on excavating a dimetrodon spine, map some dig sites (here’s a fun school dig site mapping activity), learn about other findings like the diplocaulus or “boomerang head” skull we’re looking at in the photo above. I enjoyed the opportunity to work alongside the experts and learn about all of the preparation work that is required for each and every specimen that will be in the new Paleontology hall (coming soon!) here at the Houston Museum of Natural Science. I can’t wait to see everything on display in the new wing of the Museum – it’s going to be so exciting!

For more information about what fossils are found at the dig site in Seymour check out some of the entries on the Prehistoric CSI blog, you can also find some really awesome illustrations on that site to bring the animals to life!

VIDEO: Mapping a dinosaur with Dr. Bob Bakker

As you can see from our newly-installed widget (see: right), we’re already excitedly counting down to the opening of Dinosaur Mummy CSI: Cretaceous Science Investigation, a world premiere exhibition HMNS is developing to showcase Leonardo, one of the most spectacular dinosaur mummies ever found – and the only herbivore discovered with preserved stomach contents.

Oh, yeah – it’s also covered over 90 percent of its body with skin impressions. Until someone develops a time machine, looking at Leonardo is the closest you can get to seeing a living dinosaur.

Until it opens Sept. 19, we’ll be bringing you a series of behind-the-scenes videos of our paleontology department preparing for the exhibit – traveling to Montana, where Leonardo was discovered, working to prepare the fossils of another hadrosaur named Peanut for display and much more. What do you want to see? Let us know and we’ll do our best to get it on film.

In our first video, Dr. Bakker, David Temple and several of our paleontology volunteers create a map of Peanut that will help them study the specimen as it was discovered – even after the fossils have all been removed and mounted.


You can also download the audio-only version to listen on your mP3 player by right-clicking here. UPDATE: If you can’t see the video above, you can now check it out on YouTube.
UPDATE: Check out the second video in the series – Dr. Bakker explains why Leonardo is such an extraordinary find.

Fossil and Fact Finding: Digging Dimetrodons

Today’s guest blogger is Carol Bourke, a teacher at Duchesne Academy who accompanied our paleontology team to Seymour, Texas two weeks ago. Carol and the rest of the team spent their days learning about prehistoric creatures as well digging in the field for Dimetrodon bones. Here’s what Carol had to say about the experience:

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Dr. Bakker gives a lecture to the teachers

The Paleo Field Trip was terrific; excellent, knowledgeable and friendly staff, tons of experience and great camaraderie. 

Doing real paleontological field work has been a goal of mine for a long time.  I would have settled for a lot less than the HMNS trip, but the experience I had, working with the museum team at one of the best sites in the world, was as good as it gets. 

Key to the benefits of this trip was working alongside Dr. Bakker, a fountain of facts, insights and humor.  What a guy! 

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To the untrained eye,
fossils can be hard to distinguish from rock

So, there I was, on my hands and knees, trying to distinguish fossils from rocks and hard clay, hoping to find something important and worried that I’d lose or destroy invaluable clues from the past. 

I’d expected to be hot, dirty and challenged – well, I was right!  And I loved every minute of it, well almost every minute. 

Each morning, we left our house fortified with a tasty breakfast, loaded with gallons of water, anticipating the finds of the day and knowing that we would place additional pieces into an historic puzzle.  We were rightly intrigued by the nature of the puzzle, because its solution will reveal the life and times of the first carnivorous vertebrate that walked the land, our direct ancestor and the ancestor of all mammals, the Dimetrodon

In the evening we returned to the comforts of our house tired, dirty, hungry and satisfied with our work.  Even as we relaxed and chatted, I struggled to sort out our findings and their implications.  Fortunately, I had the help of my teachers.

As a teacher myself, I often wonder what questions reside in the minds of my students, and now I’ve garnered more grist for the mill.   

Maybe you didn’t know that: 

  • You can find fossils that are at least 300 million years old, like trilobites, sponges and brachiopods, just by looking on the ground. Better watch your step!

  • An amphibian is better distinguished from a reptile or a mammal by how its skull fits onto its spine, rather than by its moist, naked skin. So much for keeping it simple.

  • Those great looking “dinosaurs” with the big back fins aren’t dinosaurs at all. In fact, they lived more than 40 million years before the first dinosaur was a hatchling.

  • Separating animals into major groups (amphibians, reptiles or mammals) can hinge on seemingly minor skeletal features. The schizophrenic angular bone, located at the angle of the jaw in our vertebrate ancestors, morphs over time into the rim of our eardrums.

  • Dinosaur skin and other soft tissues can fossilize. Just ask Leonardo.

  • Mothers should continue to count the toes of their babies, but don’t forget the fingers!

  • Centipedes are as beautiful in real life as they appear in textbooks and web sites.

  • Snakes would rather scoot than shoot, so give them space.

  • Bullets are sometimes organic, but you won’t find them at health food stores.

If you’re curious about these factoids or others, do something about it – like staying tuned to this site.  I for one will be tuned in, working on lesson plans that will integrate my first hand experience into the experiences of my students. 

Before signing off, I want to thank Dr. Bakker, a master teacher for sharing his knowledge, insights and table with me.  Thank you, Dave Temple, wildlife photographer extraordinaire and assistant curator of paleontology at the Houston Museum of Natural Science, for taking such good care of me and my fellow novices.  Chris Flis was also great to work with; he answered all my goofy questions patiently and with a straight face.  The museum volunteers were expert – – always helpful, with experience and information to spare.

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Be careful – as volunteer Gretchen Sparks discovers
here, there are dangerous creatures all around