Georgia

Osteology Everywhere: Bacon or first rib?

/ zcofran / 1 Comment

I went to a cafe today to eat breakfast and get some work done. Write, write, write. It’s important to be properly nourished to ensure maximal productivity.

The Ron Swanson diet.

The Ron Swanson diet.

But I was aghast to behold the food they placed before me:

More bacon, please.

What on earth is this?

First of all, this is not a sufficient amount of bacon.

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Secondably, this bacon is a spitting image of a first rib:

First ribs, from left to right: Human, chimpanzee, bacon. First two images from eSkeletons.org.

First ribs from the right side of the body, viewed from the top. From left to right: Human, chimpanzee, bacon. First two images from eSkeletons.org.

At the top of the ribcage, just beneath the clavicle and subclavian artery and vein, the first rib is much shorter and flatter than the rest of the ribs. As Jess Beck at Bone Broke points out, “The first and second rib give something of an awkward ‘slow song at a middle-school dance’ kind of a hug, while the lower ribs provide a more comfortable and self-assured embrace.” I mean, just lookit how sheepishly the bacon dances with the eggs in the first picture, it has ‘middle-school dance’ written all over it.

But the bacon is not totally identical to the human and chimpanzee counterparts. It’s missing their anteromedially sweeping arc, and the distal portion reaching out to the egg is fairly straight. This suggests we’re probably missing much of the original distal end. Posteriorly or dorsally (toward the bottom in the pic), it also appears to be missing much of the lateral portion including the vertebral facet. In this regard, this bacon rib looks a lot like the first rib of Homo naledi:

Full stack of ribs. From left to right: Human, bacon, Homo naledi, Dmanisi Homo erectus, Australopithecus sediba (x2), Australopithecus afarensis specimen "Lucy," Ardipithecus ramidus, and chimpanzee. Images not to scale except Lucy and Ardi.

Full stack of ribs. Left to right: Human, bacon, Homo naledi, Dmanisi Homo erectus, Australopithecus sediba (x2), Australopithecus afarensis specimen “Lucy,” Ardipithecus ramidus, and chimpanzee. Images not to scale except Lucy and Ardi. Image credits given below.

It is hard to make good homologous comparisons among these fossils and bacon, since so many are so incomplete. But it looks like the hominins are relatively longer (front to back, or dorsoventrally) compared to the chimpanzee. That is, oriented along the rib “neck,” the ventral/distal end projects far more medially beyond the proximal vertebral facet in the chimp, while in the hominins the two ends are more flush.  Ardi is really incomplete and so very hard to orient, but it may be more like the chimp (I think it needs to be rotated to the right more, to make the lateral edge more vertical like all the other specimens).

It will be interesting to see what my colleagues working on the Homo naledi thorax have to say about rib shapes and their functional importance, hopefully not too long from now.

Anyway, I really wish I had more bacon.

Fossil rib sources
ResearchBlogging.orgDmanisi Homo erectus: Lordkipanidze D, Jashashvili T, Vekua A, Ponce de León MS, Zollikofer CP, Rightmire GP, Pontzer H, Ferring R, Oms O, Tappen M, Bukhsianidze M, Agusti J, Kahlke R, Kiladze G, Martinez-Navarro B, Mouskhelishvili A, Nioradze M, & Rook L (2007). Postcranial evidence from early Homo from Dmanisi, Georgia. Nature, 449 (7160), 305-10 PMID: 17882214

Australopithecus sediba: Schmid P, Churchill SE, Nalla S, Weissen E, Carlson KJ, de Ruiter DJ, & Berger LR (2013). Mosaic morphology in the thorax of Australopithecus sediba. Science, 340 (6129) PMID: 23580537

Homo naledi: Morphosource.

Australopithecus afarensis and Ardipithecus ramidus: White TD, Asfaw B, Beyene Y, Haile-Selassie Y, Lovejoy CO, Suwa G, & WoldeGabriel G (2009). Ardipithecus ramidus and the paleobiology of early hominids. Science, 326 (5949), 75-86 PMID: 19810190

Osteology everywhere: Graffiti

/ zcofran / 1 Comment

Astana, the wedding-cake capital of Kazakhstan, is notably bereft of graffiti and street art, at least in my somewhat limited exposure to the city. The larval metropolis is all about commercial appearance, so I’d guess that aspiring street artists likely face much more than the Marge Simpson treatment for turning around to brag about their work.

Dire consequences await those who graffito tag public property.

Dire consequences await those who graffito tag public property.

Once, I did see a pretty badass street mural,

But it was in München.

but it was in München, a mere 2,620 miles from Astana.

No, there is not much in the way of secretly donated street art here in Astana, and there’s generally little hope to see graffiti-grafted Osteology Everywhere. But this weekend, I noticed these four magical letters, quickly quietly scrawled on the side of my apartment building:

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DAKA.

Two disconcerting thoughts immediately come to mind reading this. First, why the hell is “DAKA” written in Latin instead of Cyrillic script characteristic of the FSU? Second, what does “DAKA” mean out here? Nothing in Russian so far as I know, but Google Translate claims it could mean “Dakar” in Kazakh, which if true raises even more questions.

No, the safest assumption is that this tagger, my streetwise and marker-wielding dopplegänger, was referring to the ~1 million year old Homo erectus partial skull from Ethiopia, dubbed “Daka” after the Dakanihylo site of its discovery.

The Daka calvaria (Figure 2. of Asfaw et al., 2002). Counterclockwise from the top left: view from the back, view from the top (front is to the left), view from the left, a mosquito net, view from the bottom (front is at the top), viewed from the front.

BOU-VP-2/66, the Daka calvaria* (Figure 2. of Asfaw et al., 2002). Counterclockwise from the top left: view from the back, view from the top (front is to the left), view from the left, a mosquito net, view from the bottom (front is at the top), and view from the front. *Calvaria is the fancy word for ‘bony skull without a face.’

Daka isn’t the first hominin fossil to be embraced outside of anthropology. A few years ago I noticed the 4.4 million year old Ardipithecus ramidus skeleton strutting across the label of a Dogfish Head beer bottle:

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GOODGRIEF, this was almost 5 years ago.

In downtown Tbilisi, Georgia I recently spotted a Dmanisi-based duo whose tech savvy belies the fact they’re based on 1.8 million year old fossils:

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(Let’s not forget this one, from before they got smartphones)

We’ll have to do some serious fossil-finding here in Kazakhstan before they’ll let anyone put up something this awesome on the side of anything here in Astana. (Or wait…)

Dmanisi Field School: Success

/ zcofran / 3 Comments

I just got back to the States from the Republic of Georgia two nights ago; I’d thought I wasn’t really feeling the effects of the 8-hour time difference, but here I am at 6:00 a.m. feeling as fresh and sprightly as an antelope. Well, almost as much as an antelope. I didn’t have the chance to update the blog while I was in Georgia, so I’ll jot down some thoughts about my experience overall.

I had the good fortune to be able to assist a colleague in executing the first (annual) Dmanisi Paleoanthropology Field School. We had a brief field season (1 month) excavating the site of Dmanisi where the skulls and partial skeletons of several Homo erectus individuals have been found. In my previous post, I’d mentioned the site dated to around 1.77 million years ago. After being well-educated on the geology of the site by Reid Ferring, I can now say that the hominids are found between two basalts (lava flows) dating to 1.85 and 1.76 million years ago. Within these two basalt layers are A and B ashfall sediments. The A sediments are older, of normal magnetic polarity, indicating an age of 1.85-1.78 million years ago. The B sediments are reverse polarity, and were deposited between 1.78 – 1.76 million years ago. Stone tools are found through out the sequence, though Homo erectus is only known from B sediments. Enough about the geology.

Georgia itself is an amazing country. I really only spent time in the capital city of Tbilisi and the small town of Dmanisi [namely Patara (“little”) Dmanisi], and I’m sure that if I had the opportunity to see more I’d think the place is even more amazing. There is a very rich and ancient cultural heritage, and the country seems to be doing well for itself since the collapse of the Soviet Union. There’s an enduring Soviet influence, which for a simpleton like me means that there are amazing statues sprinkled about the place. Here’s a picture of the giant statue of Kartlis Deda (“Mother Georgia”), which overlooks the center of downtown Tbilisi. For a 20-meter tall woman, she was fairly difficult for me to find. Women…

The people I met and got to work with were great. The Georgians were super friendly and awesome. Here’s a picture of a lot of them (and me!) during the Paleolithic Games. This year it was only one game, using an atl-atl to hurl a spear at various targets. The top 3 winners were all named Giorgi; I only scored 2 points. Better luck next year. Anyway, I really like my newfound Georgian friends. In addition, I’m really glad to have met the other researchers and field school students. Everyone was super friendly and helpful and knowledgeable, and I think David Lordkipanidze, now head of the Georgian National Museums, has done a great job of integrating local Georgian and international researchers in the Dmanisi excavations. All in all, we really had a great crew.

It was a fossiliferous year, as it has been in the past, and will probably be in the future. Though we excavated for only a month, we uncovered a number of great fossils, including a complete hominid humerus that made the news (if I can find a non-facebook link again I’ll post the news coverage). Here’s a picture of the press interviewing Abesolam Vekua (left) and David Lordkipanidze at the site the last day I was there. Right where they are standing is where a number of hominid remains have come from. The humerus is from right behind where Vekua stands. He’s facing squares where we spent lots of time excavating, and that yielded some pretty interesting stuff; note the jumble of fossils to his left. I don’t know what I am and ain’t allowed to say, but suffice it to say that a number of cool things came out, many of which I’m sure you’ll be hearing about in the near future.
All in all, it was a great way to end this summer. I hope I have the opportunity to go back!