why working in a public park is fun.

Little kid questions of the week (both addressed to Carrie):

Small child: "Do you guys ever find anything besides bones in there?"
Carrie: "Like what?"
Small child: "Like weapons??"

I'm sure the kid meant spearheads, but my mind went instantly to a giant ground sloth holding a rifle.

Small child: "Why do they save all the dirt?"
Carrie: "We will look through it for microfossils."
Small child: "Microfossils... ohhhh like ancient germs??"

Now that one, I suppose, depends on what you consider a germ... We do get asphalt-eating bacteria, after all...

One of the most frequent questions we get from park visitors is, "what do you do when it rains?"

clearly, you SMILE ADORABLY like laura

Well, as we've had to do more than once recently, we.... go inside. Despite our dirt-covered faces and tar-stained jeans, we are CIVILIZED after all (although to be fair, if it's only raining a little, and we've got a decent tarp rigged up, at least half the staff will opt to stay outdoors: "it smells nice!").

But this is California: we don't really have weather.

this photo was taken in february; they're smiling because it's 80 degrees out. sorry, everywhere else.

People also ask which is better: digging in the cold, or digging in the heat. After several years of excavatrix-ing, I've become quite the connoisseur of digging conditions. Colder days have their advantages -- the asphalt "freezes" to the point that it chips off in these nice ovoid fragments -- conchoidal fractures, as in flint -- and you can get rid of big chunks of sterile dirt at one time.

And sometimes you find neat stuff in between the fractured pieces:

imprint of an insect wing, photo by the awesome carrie howard

SO MANY MILLIPEDES........

However, cold days mean no detail work -- no dental picking! Which means no working on awesome stuff like these two articulated camel vertebrae (still from Clyde, our camel in 5B):

Cold days, for me, also mean I'm at least 83% more likely to hit my left thumb with my own hammer before 9:30am. But I'm weird.

Warmer days, like I said, mean detail work:

i'm not sure what insect or which part this is, but it's neat

more amazing photos by Carrie

Termite gnaw marks from the Pleistocene -- very cool. The keen-eyed excavator that got them out intact -- possibly cooler (I bet it was Carrie -- apparently this is We Love Carrie week).

So, warm days = melty asphalt and pretty fossils. However, warm days eventually turn into hot days, which eventually turn into oh-my-god-i'm-dying-get-me-an-iced-tea. We've got another 2 months until then, though.

Another keen-eyed excavator (your truly, to tell the truth) spotted a new instance of the family Suidae at Rancho La Brea....

yes, it's a pot-bellied pig. no, it's not george clooney's. damn.

but, alas, not exactly Pleistocene in age...

may the force be with ryan

Sad but true: our Lone Male Excavator has left us for more exotic locales (grad school in plant and soil sciences on OAHU) and we miss him already. Ryan has been a careful and conscientious excavator, a funny dude, a good friend, and last but not least, an incredibly snazzy dresser (plaid + camo = AWESOME).

Yes, we will miss his hard work, his dedication to replacing shoring boards in the heat of summer, and his enviable ability to reach things on tall shelves, but we will also miss his encyclopedic knowledge of all things Star Wars, his willingness to talk in funny voices for our amusement, and perhaps most of all...

his unparalleled ability to re-purpose old broken office furniture during his lunch break. The above photo may appear to be an ordinary office chair, but look closer! It is actually an office chair attached to another chair because it broke off its original base. The wooden legs of the base chair have been careful sawed at an angle for maximum comfort.

And what became of the base of the chair, you ask? BEHOLD:

This is quite possibly my favorite piece of furniture ever. It's an end table! On WHEELS! This handcrafted beauty is made of another chair (with the back sawed off) screwed onto the base of the broken office chair, with a piece of laminate for a top. And it's the perfect height for chips and salsa!

Finally, Ryan's coup de grace:

A genuinely well-made desk for volunteer Christina, made out of the side of box 10B (I think it's 10B).

In conclusion: Ryan is awesome! We totally miss him! He is funny and us taught about plants and how to sharpen tools and such! However, on the bright side: we now have a couch to sleep on when we go to Oahu...

Godspeed, Ryan, and may the force be with you.

measure for measure

Earlier this week, we measured out the left half of an American Lion pelvis (or, more anatomically correctly, an innominate). Whilst typing this into yesterday's entry, I realized I've never actually explained what "measuring" a fossil entails, let alone why we do it.

"Measuring out" a fossil means recording the location of two to three of the bone's anatomical points (usually three) within the context of a 1m x 1m x 25cm grid. For instance, take our most recent innominate:



The three dots and abbreviations above represent the three different anatomical points: IC stands for Illiac Crest; PT means Pubic Tubercle, and DP means Dorsal Posterior (which isn't actually a point -- it's a general orientation. This portion of the bone is broken off, so there isn't an actual feature to measure. Instead, we measure an arbitrary point, and name it after the point's location in the body: Dorsal, or toward the spine, and Posterior, or toward the rear end).

Each of these three points gets three pieces of data of their very own: measurements of the fossil's location below the original surface of the deposit (abbreviated as "BD" for "Below Datum"), north of the southern most line of the grid (N), and west of the easternmost line of the grid (W). These measurements are written into our field notes, and carbon copied (literally, with little blue pieces of carbon paper) onto 3" x 5" cards. Confused yet? Fear not, it sounds much more complicated than it actually is. But here's an enhanced version of the final product:

Remember Algebra class waaaay back in 9th grade? Wait, let me rephrase that -- remember any of the math from Algebra class waaaay back in 9th grade? Yeah, me neither. However, had you paid closer attention to the graphing portion of your text (and less attention to Spitball Trajectory 101), you would recognize those three columns of numbers as coordinates within a 3-dimensional graph. For example, for the IC, x = 43, y = 42, z = 32.5, etc. By recording all of these coordinates, we're able to later reconstruct the fossil's position within the deposit. And in doing that, we can learn all sorts of nifty things about how skeletons fall apart within a tar pit, or which animal got trapped first, or how asphaltic sand shifts underground over time, and so on and so forth.

A better photo narrative of a fossil's journey from grubby, dirt-covered groundling to a finished, fully prepared specimen is forthcoming, but until then, I hope this has been helpful. Or, at the very least, has inspired you all to pay closer attention in Algebra II.

The story thus far

Between February and July of 2006, 16 ginormous fossil deposits were found underneath what used to be Ogden Dr. (and what is now LACMA’s fancy new underground parking garage). With construction deadlines looming and fossils constantly appearing underfoot, Robin Turner over at APRMI came up with a brilliant plan: rather than halting construction for an indefinite period of time to excavate each and every fossil, she boxed the deposits up as if they were colossal oak trees, lifted them out of the earth with an equally colossal crane, and set them aside for later study. These 16 deposits took up 23 tree boxes, and thus….

"PROJECT 23" WAS BORN!
(Well, “Project 23 plus 2 fossil trees, 327 buckets, a whole bunch of film canisters and plastic baggies filled with other assorted fossils, and 20 plaster jackets containing the bones of one semi-articulated mammoth with complete tusks," but you get the idea, right?)

So what's in these boxes? We don't know! It's a mystery! We won't know until we open up them up! It's like a paleontological Christmas! If the deposits are anywhere as dense as Pit 91, we could have literally hundreds of thousands of fossils on our hands. And if we were to include all of the microfossils (bug parts and tiny shells) in that estimate: maybe even millions.

That having been said, we do know this:

This is the top of Deposit 1, and these are the bones of a sabertoothed cat. But furthermore, these are the semi-articulated bones of a sabertoothed cat: a hip bone and a lower hind leg, to be exact. Further furthermore, we know that these are the bones of a fairly young sabertoothed cat; since the epiphyseal line between the main part of the bone (the diaphysis) and the end of the bone (the epiphysis) is visible, we know that the animal was young enough that his bones hadn't finished fusing. We rarely, if ever, find this sort of articulation in Pit 91. The fact that we're finding this sort of thing right off the bat is fairly-to-extremely awesome.

Further further furthermore:

This is the scapula (shoulder blade) of a giant ground sloth (and Ryan's feet) (please note the tar-y socks). Giant ground sloths are AMAZING and made entirely of WIN, and their presence in this first deposit is an extremely good omen.

More soon...