Meet “Hank,” the micro-vertebrate sieving machine
By Prof. Phil Manning, Children's Museum Paleontologist-in-Residence
Photos by The Natural History Museum, London
We’ve been working on a most extraordinary deposit of the Morrison Formation, which is nicely underpinned by the Sundance, another Formation of rock that was laid down in the Sundance Seaway approximately 165 million years ago. We love all of these fossils, but our main focus, really, is on the lives of the dinosaurs found in the Morrison Formation—Brontosaurus, Diplodocus, Brachiosaurus, and other iconic sauropods. We hope to try and pick apart the beautiful traces of past life that we’re finding in the Morrison Formation so that we can have a go at reconstructing this lost world and forgotten lives.
In order to reconstruct this lost world, we aren’t just interested in the big dinosaurs. We want to paint the big picture about life during the Jurassic Period. So we are also very interested in the really small fossils—including the micro-vertebrates. These aren’t always the tiny remains of dinosaurs, as the Jurassic ‘Titans’ tend to be pretty big. They’re the small beasties that were running between dinosaurs’ toes. The more we know about micro-vertebrates, the better the picture we can paint of the Jurassic Period itself.
How do we find micro-vertebrates?
When searching for micro-vertebrates, we generally deal with two sorts of sediment. As mentioned in a previous post, one type of sediment exposes fossils when it’s rained on. The other type is generally is rich in volcanic ash. And when it gets wet, it swells, which covers up the fossils even more. This makes it easy to overlook these tiny creatures.
Traditionally, scientists have uncovered these micro-vertebrates by sieving—placing sediment into a screen and shaking the screen around in water. It’s time-consuming work because you have to be very gentle during this process or the material can be damaged.
David Ward, Scientific Associate with the Natural History Museum in London, has made a career out of making huge statements about some very small things. He has spent his life sieving micro-vertebrates. He has developed a machine where, thanks to the use of running water, the specimens don’t really move very much. Water moves around the material and actually separates the tiny fossils from the encasing sentiment.
We call this contraption “Hank”
As you can see, “Hank” is a large water tank sitting on a wooden platform with hoses running to smaller tubs. Sediment from the dig is placed into a sieve in this giant tank. Recycled water is pumped into it. The running water separates the sediment, revealing the specimens, and collecting the clay and sediment in the bottom of the tank. The water is then recycled through the smaller tubs on the ground and ultimately pushed back into the large tank to perform the cycle all over again.
What will we find as we sift through all of this dirt? We really have absolutely no idea what we’ll find. That’s part of the excitement of it all. We’re exploring tiny worlds and discovering amazing things. It really sparks your curiosity. David has built a few of these machines at other dig sites over the years and told me, “We’ve found small pieces of turtle, crocodile, pterosaur, small dinosaur teeth, and mammal teeth.” It’s exciting to think about what “Hank” will help us discover during this dig season.
The sediment we’re collecting and sieving is very fine. But luckily this machine is particularly good at separating specimens from the clays that hide much from site. In the morning, after everything has settled, we have to dig a lot of mud out of the giant settling tank. This doesn’t sound like a very fun job...but it’s worth it. Without “Hank,” we would miss a lot of the important details that will help us solve the mysteries of what happened in the Morrison Formation.
Some of us have become best buddies with “Hank.” We’re certainly glad he’s part of our team.
Stay up to date!
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Mission Jurassic is a $27.5-million project that will be brought to life through the generosity of donors. Donate now on our website, or for extraordinary naming opportunities check out our Mission Jurassic Field Guide or contact Amy Kwas at 317-334-4608 or AKwas@childrensmuseum.org.