Friday, July 17, 2009

The Real Deal

This past Monday we began our first post-training week and settled into the schedule we will have the rest of the summer - rehousing on Monday, Wednesday, Friday, georeferencing on Tuesday, and elements descriptions on Thursday.

As we become more familiar with rehousing and fossil handling techniques, we're settling into a solid pace of pulling, rehousing and returning a few cart-fulls of specimens to the collections each day. We completed nearly 50 rehousings during the past week.

One highlight was figuring out, with guidance from Carl and Ivy, what to do with the tray of bones set in a large plaster block that we'd mentioned in the previous blog post. Such an arrangement is known as a plaque mount and is intended for display. Since the plaster block is far too large to fit in any of the boxes we have (it takes up nearly the entire drawer), we used tri-rod to stabilize it in the drawer, and if we come across such a mount where parts of the fossil are raised above the top of the tray, we'll make a choroplast riser to protect the bones from other trays scraping on top of them.

A second challenge that arose came not from a fossil, but from a fossils' documentation. Some specimens had notes with them written on newspaper over 100 years old - the oldest so far is from 1898. To keep these notes - which have become pretty tattered - from further deteriorating, we used archival quality tape to mend rips and reinforce any part that seemed prone to tears.

We’re making a big dent in the type collection - or it certainly feels that way. The process is going much more smoothly and we’re continuing to find our niches.

Georeferencing: Where in the world?
On Tuesday we had a briefing with Chelsea about our first round of georeferencing from the week before. We got the chance to ask her about any problems we had run into and also share any helpful hints we'd figured out during our first batch of localities. Since the objective of georeferencing is to take information about the location of a specimen's origin given by the excavator and plot it on a current map - we need to find the country, state/region, and county/division of the excavation site.

One challenge we ran into is that some territorial boundaries have changed since the fossils were excavated. For example, we were working on a locality listed as "Bugti, India" - excavated in 1923 - and weren't making much progress until we figured out that the excavation took place in what is today Pakistan.

The card catalog turned out to be one of out greatest assets in narrowing down options for a given locality. Cards often contain additional notes about the site, such as nearby towns, major roadways or alternate spellings. The first card pictured here is a georeferencing dream come true, containing both a street map on the front and a geological map on the back. Others, like the one pictured below, provide less help, but in such cases we can turn to field notes and other sources.

We divided up the remainder of the master list of localities amongst ourselves. After filling in the territorial information, we'll go back and find the latitude and longitude - using field notes, shipping record, and Google Earth. We'll have plenty more questions for Chelsea when we get to that stage.

What's that smell? Thursday's Tour

After continuing our work on element descriptions, our Thursday tour of the Vertebrate Zoology Osteology Prep Lab lead by Dr. Neil Duncan, Supervisor, turned out to be quite the olfactory experience. Dr. Duncan showed us how he reduces fleshy dead carcases, sent to him by many various departments in the museum, into clean sets of ready-to-study bones.

One technique is performed int the degreasing and maseration room - where bones are submerged in water and left to rot over time in their own juices, go bacteria!

Although that may have sounded icky when Dr. Duncan first described it to us, that process pales in comparison to what goes on in the 'bug room.' Specimens are placed in tubs with thousands of flesh-eating beetles, pictured below on the skeleton of a fish. These little guys get the job done and can clean some small skeletons in less than a day. But be careful not to leave a specimen in there too long - they'll eat the bones if they get hungry. Dr. Duncan also has to worry about keeping the beetles contained. In a museum with taxidermied animals on display and in collections, a beetle escape could reek havoc. The beetle tubs are equipped with lids and there is a layer of glue sealing of the gap under the door to serve as a second line of defense.

Lastly, Dr. Duncan showed us the room where whale bones are stored. Like the collections we saw on the mammology tour last week, this was another example of how modern and paleontology collections have the same issues when dealing with space for specimens, especially large ones such as those from large animals like the blue whale. Finally, we got to go into the fridge at a chilly -4’F temperature that's used to preserve
carcases before they go to the bugs.

A whale skull and vertebrae from this week's tour -

large specimens such as these require special attention in moving and storage.

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