Wednesday, November 7, 2007

Day 3: It just keeps going and going and going and...

Today, the team continued to excavate the new associated Dimetrodon layer that was discovered yesterday at the Amy site - and it just keeps on going. Just today, they've found additional fin spines (more than 6 so far) of extraordinary quality; several unidentified, large chunks bone in the same level as the fin spines as well as one at a slightly higher level; and a set of Dimetrodon ribs.

Chris and Kathy work on excavating two separate layers at the Amy site early this morning. The lower level contains the associated Dimetrodon skeleton discovered yesterday.

A close up of the lower level of the Amy site. Dimetrodon fin spines extend from the bottom right of this image to the top left, with ribs and additional fin bones crossing them from a different direction. Only the right half of this layer was visible yesterday. Soon, they'll have to start excavating from the top of the hill in order to avoid a collapse. Dr. Bakker estimates this skeleton will take at least 16 people days to completely remove from the site.

Chris maps the bones on clear plastic as they are uncovered. Since even photographs can skew the direction of the bones slightly from their true location, this technique ensures accurate measurements, even after the bones have been removed from the site.

Close up of the bone maps. Later, they'll be digitized for analysis.

The team also investigated a mystery tooth that kept popping up - 4 times in all before they figured out what is was. Neal found the first one yesterday - a tiny, tiny tooth with microserration - visible only under magnification - that was much more delicate than any other tooth found at the site. 3 more were found this morning, including one about 190 mm above the main Dimetrodon layer at the Amy site. Then, we found this at the K2 site today:

"Look at that fang!" Dr. Bakker found this tooth in 2 pieces at the lower level of the K2 site, where the Diadectes vertebra was discovered on Monday. It's much sharper, more fluted and has a finer saw edge than most Dimetrodon teeth, and it has very fine serration on both sides. It was located close to the front of the jaw and would have created a very different kind of wound.

This is a shed tooth from an adult Dimetrodon loomisi - "the cheetah of Dimetrodons" according to Dr. Bakker. While most larger Dimetrodon were chunky, this one was graceful. Still, it was a "big, honkin' carnivore," and the tooth looks very similar to that of a saber-tooth cat. From the adult tooth, Dr. Bakker identified the tiny mystery teeth the team had found were actually the juvenile versions of this species.

So, no brand new species - but, a new type of Dimetrodon is now known to be present at this site. And - it was eating Diadectes - more CSI evidence of the Permian ecology. "We found a bullet, literally mm from where the Diadectes veretebra came out. This is pretty intimate crime scene documentation. We've got six other bullets in this area. But this one (loomisi) is more like a sniper bullet, or a rifle bullet. Dimetrodon grandis was more like a .45."

Dr. Bakker also revealed another set of Dimetrodon spines at another layer in the Amy site - bringing the total number of discrete layers in this one hillside to 6. "What we're looking for is the next thing - no matter what it is. We're interested in everything, so we can figure out the context of what was happening here."

New Dimetrodon vertebra in a new layer at the Amy site.

Later in the afternoon, 2 of Kim Beck's science students- Tarrington Rivers and Jacob Richardson - joined the team.

Kim Beck, Tarrington and Jacob look for fossils on the surface of the main dig site with Dr. Bakker.

They catch on quick! After only a few minutes, Jacob and Tarrington had amassed an impressive collection of fossil fragments, including a shed tooth.

Jacob and Tarrington even found a new spot that the team hasn't looked into yet, with a lot of Dimetrodon and Xenacanthus teeth on the surface. By the time they left, they were able to identify teeth, spine, claws, and skull fragments. According to Kim, "they did really well, especially since they were only on site for about two hours. They're looking forward to coming back Saturday." And they'll be posting their thoughts about the experience here, so check back soon.

Also, check out new photos on yesterday's post.

Your questions, answered

Kim Beck's students at Seymour High School have been following the HMNS dig team's progress this week on the blog, and they sent Dr. Bakker and the rest of the team some great questions about what has been happening. Around the breakfast table before today's dig, he had these answers for them:

From Jessica J.: How did the Daffy Edaphosaurus get it's name?

When he discovered it, Professor E. D. Cope named it Earth Lizard (Edapho = Earth, Saurus = Lizard.) "Daffy" is a nickname given to Edaphosaurus by my professor at Harvard, Al Romer, who liked this species very much. Yes, some professors at Harvard have a sense of humor.

From Chelsea D.: What was the use of Lysorophian's long body?

Snaking through the soil or mud - similar to the way today's salamanders. Many amphibians today have small bodies. This species also had a nasty bite, much like today's short legged amphibians. These seem to go together.

From Edder J.: What is your favorite dinosaur? What is the coolest thing you've found?

Well, what we are digging in Seymour were actually alive even before the dinosaurs. My favorite Red Beds species is The Texas Snotnose - known officially as the Dasyceps. They had huge mucus glands, tiny teeth and very weak jaws.

The coolest thing we've found are the multiple layers of victims - showing us that the bones are still organized together, not jumbled up as previously thought. The pattern of coprolite we've found is also very interesting.

From Andrew L.: I'd like to learn more about the Woolly Mammoth.

In North Texas, you'd likely have a species called the Southern Mammoth. They were huge - over 13 feet tall at the shoulders.

From Nick W.: How many dinosaurs have you found?

Probably over 400 individuals. For Red Beds animals (which were around even before the dinosaurs evolved), we've found at least 35 Dimetrodon at our site here, as well as a totoal of 100 individuals of many different species.

From Ashley H.: I want to learn more about the ocean and the animals that live in the sea. Also, I would like to learn about the crinoid.

300 million yers ago in Texas, the ocean was very warm, with huge reefs that are full of critters. But there were no whales, modern sharks or even many clams - though there were plenty of brachiopods. There were, however, thousands upon thousands of beautiful things that look like plants, but were actually animals - crinoids. They were like a starfish turned upsidown. Some - such as feather stars - are still alive today. They're very graceful and otherworldly. If you ever get to D.C., there is a beautiful display of crinoids at the Smithsonian.

From Hunter D. and Veronica G.: How many years of college did you have to go to be a paleontologist? What is the greatest thing you have discovered?

I've got 9, but there are some very good paleontologists who learned on their own. It certainly helps to study biology, as the species alive today are often the descendants of the fossils we find. I'd say 6 years is a good number to shoot for - that would give you a Master's level degree in the field.

The greatest thing I've discovered is that CSI works to help us figure out who ate whom. For example,we now have evidence that, at least at some places, some times, Dimetrodon ate Xenacanthus sharks.

From Hunter H., Kevin P., Taylor G., and Jacob R.: How do you carbon date a fossil?

If you're lucky, the soil your fossil came from has traces of radioactive volcanic ash. The minerals in such ash start to decay right away, at predictable rates. If you've got the right machine, it can tell you how long the material has been decaying. But, we can't use carbon dating at the Seymour site - it doesn't allow us to date far enough back in time. Here, we compare what we are finding to similar fossils at sites that can be dated, for approximate ages.

From J.S.: What is so interesting about rock fossils?

They speak to us of times far, far away. It's like going on a time safari to another world.

From Jacey B. and Kelce S.: How can you figure out so much about something just by seeing parts of the fossil? How do you choose the sites you want to dig?

Mostly, the parts are bones, but they have marks on them where the muscles and ligaments were attached. Ribs can tell you how big the guts were. A braincase can tell you the size of the eyes, and about the sense of hearing and smell. Claws can tell you if the animal was capable of digging or climbing. We also have footprints - which can tell you how an animal walked, among other things - and coprolite, which can tell you where and what an animal was eating.

The site we're digging this week was easy to pick - it has been known as a locality for Permian fossils since 1882. And we've found new ones.

Also from Jacey B. and Kelce S.: Is it hard to tell if something is a fossil or just a rock?What killed all the dinosaurs?

To tell if a rock is a fossil, you need a hand lens. With one, you can see the microscopic structure of the bone - the holes left by blood vessels, spots where the muscles attached and in some cases, with a really good microscope, the bone crystals as well.
We don't have dinosaurs at this site - they came later in time - but we do have evidence of the first mass extinction. At the end of this period, all teh big herbivores were gone. The weather changed worldwide, becoming really, really dry. Nasty, nasty - salt flats and salt ponds. Horrible.
From Ryan M.: How much did Dimetrodon weigh?

We have three kinds of Dimetrodon. The really big one weighed as much as a really big tiger - about 600 pounds. Some of the little ones weighed no more than 60 pounds. So, it was like cat family of today - which has giant cats, bobcats and housecats.

From Matt P. and Tarrington R.: Have you ever found a complete Seymouria fossil?

No, but my friend Dr. David Berman has found 4 - in Pittsburgh and in Germany. All of them were curled up in theri burrows, nose to tail, every bone in place.

From Kaitlin N.: Does it take a college degree to be a paleontologist?

Usually, yes. But many of the people who clean fossils and help with exhibits don't have advanced degrees.

From Clarence F.: Is paleontology fun and easy?

Yes, because you get bitten by ants and chased by millipedes, bitten by chiggers and poked by 3 kinds of cactus. Yes, because you get to look back through time, millions and millions of years to see all kinds of weird and wonderful and wonderful.

Is it easy? No. It's hard. But it's fun hard.

From Aaron B., Kyle H. and Callie P.: What feeling do you get when you discover a new species? What do you use to dig in the soil? How many fossils, on average, do you find per dig?

We laugh, we cry, we fall over. It's like shining a light into a dark, magic place and finding something looking back out at you.

For digging, the most important tools are your eyes, your fingertips and your feet. For non body-parts, the most important is good glue - you need to stabilize the fossil before you can dig. You also need scrapers and brushes. And Ziploc bags.

Here, we find lots of fossils on every dig. Up to hundreds of individual bones.

Several of the students were fascinated by David Temple's diverse background - including his talent for cooking bugs.

From Brandon T.: What do bugs taste like?

Generally, the flavors are very mild and most dishes that incorporate insects are flavored, so in general they taste like what ever you cook them with. There are a few exceptions, I once tried a cockroach that was roasted and seasoned with Tony Chachere’s Creole seasoning prepared by D. G. Gordon, I didn’t care for it, there wasn’t enough of that cajun spice in Louisiana to mask that taste. (Tony Chachere's is a good choice for bug cooking and as the company’s own claim states- “Good on everything” )

From Carrie H.: What does it take to make chocolate covered crickets and grasshoppers, and how long?

Chocoate covered insects are fast and easy, Let’s say you wake up one morning with a powerful craving for chocolate covered crickets. First catch or purchase some crickets, ideally you want to get them before they have gotten their wings. Purge them for a day or feed them spearmint leaves. Kill them by placing them in a paper bag in ther freezer. Remove them from the freezer and then place them in a colander and wash them, gently pat them dry on paper towels. Place on a lightly greased baking sheet and dry roast at 300 degrees for 10-15 minutes, you will smell them when they are ready, they should be crispy when you remove them. Melt the chocolate in a double boiler as per the cooking instructions, using small tongs or tweezers dip crickets individually into the chocolate and then lay them out on wax paper, you can dust them with powder sugar or cocoa to make them extra fancy.

From Sklar O.: Can you give me some tips on cooking bugs?

A great way to try bug eating is to google “Hotlix."They sell commercially prepared bug snacks. At the Museum we have a vending machine stocked with them, no soda machine, no candy, cookies or chips just crickets, mealworms, and scorpions. One of my favorites is the Larvettes Mexican Spice flavor, these are roasted and seasoned mealworms. I have prepared my own roasted mealworms and I can never get the to turn out quite as well.

From Lance B.: Why does Mr. Temple eat bugs?

Because I can. You may not know it, but you're a bug-eater, too. The USDA allows a certain number of insect parts to be in different kinds of food - like tomato paste, chocolate and cereal.
Also, at a museum, we're all about touching, handling and seeing things - but there are very few things you can taste. When was the last time you licked a T. rex? It's another way to learn, and investigate the world around you. Plus, there are cultures all over the world that eat bugs regularly - we're one of the few that don't.