16 November 2009

update: more sabertoothed cats and kittens

Solar flares over our pulley. From Back in Dep 1
As I reported last post, we've moved back into the big box: Deposit 1!! And look how excited everyone is:

Volunteers Christina Lutz and Tara Thara. From Back in Dep 1

Those are the smiles of happy fossil finders. Why? Because they're actually finding fossils again! Between mostly planty deposit 7A, and really hard and sterile parts of deposit 1, we're been spending entirely too much time digging up dirt rather than fossils. Dirt = not fun. Fossils = awesome. It's very simple.

I've posted many, many pictures of this bone bed before (it's where we found our North American Lion skull and assorted long bones). And it's once again producing some really great feline finds:

Sabertoothed cat skull! From Back in Dep 1

The big dusty skull-looking thing on the bottom is a... big, dusty sabertoothed cat skull, with a complete sabertoothed cat pelvis immediately above it. And look a little above the skull and to the right:

Smilodon saber in situ. From Back in Dep 1

It's a complete sabertoothed cat saber!

Smilodon saber in one piece! From Back in Dep 1

And in the grid directly across from this one, we found 2 more sabertoothed cat kitten sabers:

Volunteer Steven Wintergerst holding a Smilodon kitten saber
From Back in Dep 1

This may bring our (estimated) minimum number of sabertoothed cats in this deposit to around 7: 3-4 juveniles, 1 sub-adult (teenager) and at least 2 adults (I will have to double check these number with the lab). It's actually possible to match sabers to skulls, by taking casts of the alveolus (tooth socket) and comparing the cast to the tooth! This is something we might want to do in the distant future; because this deposit is so small we may be better able to discern which bones belong to which individual cat -- especially for these 4 "kittens" we've found. Yes, they're all young, but they're not of the exact same age (which makes me think this isn't a singular litter that got stuck). So by determining the age of each young sabertoothed cat bone we find, we can figure out whose limbs are whose, and then perhaps extrapolate from that how much the asphalt has moved/disturbed the skeletons since they first got stuck 10-40 thousand years ago.

In non-mammalian news:

Turtle shell! From Back in Dep 1

2 partial turtle shells have come out of the formerly sterile areas west of the main bone deposit. Turtle shells are made out of a number of interlocking plates, and while the individual plates are extremely common, articulated/associated ones are not -- in fact, these may be the only even semi-complete shells we've ever found at Rancho La Brea. Trevor's been working on them in the lab, and has one of them somewhat reconstructed (which he will hopefully tell you all about at some later date if he ever gets around to making a blog post, hint hint).

FINALLY two other items of business:
1) This is Carrie!

New excavator Carrie Howard! From Back in Dep 1

She works here now! She likes rocks and photography and is generally great.

2) I don't often share links on here, but for those who are interested in science education in America and the general fight to keep evolutionary biology from being grievously misunderstood may find http://www.dontdissdarwin.com/ helpful.

Next post: so, what's in that barn-looking building next to the trailer?

Greg A. hunts for lunch by Pit 10 From Back in Dep 1

No, it is not dinosaur! It is a degreaser, which is far more useful and hopefully far less dangerous! More later.