Thursday, November 8, 2007

Day 4: Pirates of the Permian

Dig what you can! Give nothing back!
Dr. Bakker's re-interpretation of Jack Sparrow's Pirate Code was a fitting theme for today's dig, as bones popped out of the sediment like buried treasure.

If you saw the photo post earlier today, you know it started out with a bang - right off the bat, Kathleen discovered a Dimetrodon fin spine still attached to a vertebra (a first for the site) and Shirley uncovered a tiny Xenacanth tooth embedded in Xenacanth cartilage - very unique. While David and Neal headed into town to visit Kim Beck's class, several others headed over to the spoil pile (a location on the opposite site of the hill the Amy site is located, where a different museum;s team discarded a lot of really great - but not large - fossils). They found this:

A huge Diadectes vertebra, in one piece - you can see the body of the vertebra (the part that connects to the other vertebrae in the spinal column) at the top left. This is the same species that was discovered at the K2 site on Monday, but from a different - and significantly larger - individual.

Chris, Kathy, Kathleen and Shirley continued to excavate the lower level of the Amy site, and discovered that some of the spines are actually what looks to be a full rib, tapering to the end of the site.

The rib is visible arcing across the top of this photo. You can see how the bones taper to a very small size at the far right of the photo, as well as how this would have been wrapped around a Dimetrodon's belly.

VIDEO - Making a map of our buried treasure. Kathy explains the process of mapping a bone layer, which documents exactly the way each bone was laid out in the bed, helping the team determine how each of the bones relates to the others, even after the bones have been removed from the site.

This tooth was also newly discovered today - it has the characteristics of Dimetrodon loomisi, the "mystery animal" the team identified yesterday from a giant fang found at the K2 site. A very long root is visible attached to the tooth - meaning that it was lost after death, not while eating. This may identify the entire Dimetrodon in the lower Amy layer as this species.

In addition, everything in this layer is facing north, and there are many types of fossils found - an amphibian, 2 species of Dimetrodon and Xenacanthus so far. This indicates that it was probably a stream bed of some kind, where multiple animals got caught up after death and were then covered with soil.

Led by Johnny Castillo, half the team moved up the hill opposite the Amy site to begin to remove plaster jackets that were created during the last dig trip to stabilize and protect the fossils found at the Spine site. These jackets contain an impressive Dimetrodon spinal column that has several of the fin spines in place, extending upwards from the spine. Before it was covered, enough was visible that you could actually envision the fin of this giant beast as it was laid out 290 million years ago. The team works on removing dirt from around the plaster jacket, while also collecting any bones that may have been preserved in the surrounding dirt. The object is to make the pedestal of dirt underneath the plaster cast as narrow as possible, in order to make flipping each 500-pound jacket easier.

Adam works on removing soil from underneath this jacket, to create a smaller pedestal. At the end of the day, they had found multiple additional vertebrae in the surrounding soils, and so much had been removed that the plaster cap appeared to be floating.

While all this was going on, David and Neal were bringing the dig into town for the students at Seymour High School. They brought in fossils from the site - as well as a bunch of rocks - and challenged the students to tell the difference, while also discussing local geology.

Students examine Xenacanth coprolite - shark poop - found at a new site on Monday.
The students learned about arthropod footprints, trace fossils (which show how the animal lived - like fossilized burrows) and one very unique characteristic of this area. Bones from 10,000 years ago - like Mammoth and Saber Tooth Tigers - are found right on top of 300 million year old fossils like Dimetrodon. The stuff in between - like the entire history of the dinosaurs - just washed away.

Angie Bourland looks at a fossil passed around during class.

As the Museum's official bug chef and 2007 Houston Chronicle's Most Adventurous Palate, it seemed only natural that David had also brought bugs to pass around. And eat.

David passes out dried, BBQ-flavored meal worms for the class to try. As he explained, "Everyone in here is an insect-eater. If you look at the USDA requirements for your Cap'n Crunch, your tomatoes, your peanut butter - you'll see a certain number of insect parts are allowed." To which junior Hunter Rush replied, "Wait a minute - they put insects in my Cap'n Crunch?!?"

SHS freshman Nick Wiles eats a bug. And promptly runs to the sink to "wash it down."

All in all, a productive day - for the team, and the students. They did "dig it all" - but maybe they gave something back, too.

No comments: