17 October 2009

update: out of 7A, back in to deposit 1

they escaped from the tar pits, but not from each other: these two dragonflies were
found flying around together, attached at the hip by asphalt. Michelle kindly helped
free them. From 7A and back into 1

Right. So we've been working steadily in deposit 7A, and are about 1/2 a meter down in all areas. There were three bones immediately visible on the surface (all sliced by the tractor that found them, and horribly dried out), but other than that we've yet to find any substantial vertebrate fossil deposit. We've found a few scattered pieces of turtle shell (not to mention some extremely odd fragments of mineralized bone -- very rare for Rancho la Brea!) but none of the big jumbly bone masses we've come to know and love. What we have found:

Shells shells shells! From 7A and back into 1
Gastropods! And lots of them.

excavator hand for scale, From 7A and back into 1

These freshwater snail shells are further contextualized by the immense amount of plant material we've been getting out of the deposit as well; the northeastern corner of the deposit is filled with what appear to be tree branches (but possibly roots). Additionally, there's some interesting stratigraphy going on in this deposit: layers of river sand and large rounded rocks.

But as of yet no big vertebrate fossils. Boo.

For that reason (and because we're acutely aware we're already one year into a five year project!), we've put deposit 7A on hold, and re-doubled our efforts in deposit 1 (the big box we first started in).

That's usin' your head, Russ. From 7A and back into 1

And we've made some really impressive progress! But more on that next post. Until then, I leave you with this month's "What is it?" Check out the photo below, and leave a comment with your guess of species and element! Correct guesses win a congratulatory shout out on the next post, and the knowledge that they have bettered their internet peers!

I'll give you a hint: it's a fossil. From What is it?
Happy guessing!


Neil said...

Hmmm....furculum the wishbone from the world's smallest Teratorn?

Boogie Wonderland said...

*crosses fingers*
Right-side scapula, from a falcon or small eagle.

Yo Momma said...

It looks like a fossilized slug. Is it a petrified slug? :-)

andie said...

furculum is closest so far, but still a bit off...

Boogie Wonderland said...

Turtle coracoid then.

Yo Momma said...

Is it a clavicle? But to which animal I know not. It's a small animal, that's for sure.

andie said...

element is correct -- it is a clavicle! but small animal, it is not.

Spencer said...

Wait, which one was 7B?

Pinku-Sensei said...

The gastropods look just the same as when I was examining them 25 years ago for my M.S. Thesis. They're all Lymnaeids. Most of them, the larger ones are Stagnicola proxima. The genus has a distinctive texture, which I can see in the best preserved big specimens. The smaller ones are most likely Fossaria modicella. They indicate shallow sluggishly flowing water that may dry up briefly during the summer.

Rich (now Vince) Lamb