The stream-severed spine

I recently returned from Mangystau, a geologically captivating former seabed in West Kazakhstan. Places like this, or the Tien Shan mountains in the South and Altai mountains in the East, always make me wonder why anyone would decide to build a capital city in the wastes of Aqmola. Astana sprouts up from a sterile steppe, sparingly sprinkled with streams and lakes. Out west, though, are breathtaking landscapes and landforms, such as the giant rocky spheres of Torysh:

Traversing the

Traversing the “Valley of Balls.” It is not yet known what caused these rock formations.

Sherqala (“Lion City”), a rocky uplift that centuries ago hosted a defensive acropolis:

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A flooded salt flat vertiginously reflecting an alternate reality:

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A pile of earth that’s really an octopus waiting in ambush:

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The perfect place to set up camp.

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As I’d pointed out the first time I came out here last year, this rocky terrain is littered with lifeless remnants of the animals that used to call this place home. So many bones reflecting such biodiversity, just lying on the surface. This year, though, I found a subsurface skeleton, teaching an important lesson in taphonomy. Taphonomy (“burial law” from Ancient Greek) is the study of what happens to an animal’s remains from the moment it dies to when it is discovered eons later. This field examines geological and ecological processes that determine whether fossils are found intact or smashed to smithereens.

Walking down into a small gully by our campsite, I noticed some giant lumbar vertebrae eroding out of one side:

Waist-deep in mud. One vertebra is clearly visible, and to its right, beneath a rock, are the spinous processes of two more vertebrae.

Waist-deep in mud. One vertebra is clearly visible, and to its right, beneath a rock, are the spinous processes of two more vertebrae. Notice the differently colored stripes of soil – these are different layers (“strata”), reflecting different periods that soil was laid down on the earth.

I was elated to espy this spinous surprise, but I wasn’t expecting to see what was on the opposite side of the gully:

Died doing a misguided impression of an ostrich.

Died doing a misguided impression of an ostrich. On the left you can see the back of the skull and the first cervical vertebra, then the spine submerges and reemerges to the right.

Sure enough, this once complete carcass was drawn and quartered, pulled apart by the liberal application of time and life-saving water.

Digging out the skull on the west bank, right across from the lumber spine on the east face. The different soil layers (

Digging out the skull on the west bank, right across from the lumber spine on the east face (circled).

Getting our hands a little dirty, we found the face of a camel. It is hard to say how long ago it lived, how long it took to get buried by a few inches of dirt, but I would guess at most only a few decades (but I’m not a geologist, so who knows). It’s also unclear how this animal was bifurcated: Did the camel die and get covered over with soil, and then later a newly forming stream carried away the soil harboring its torso? Or did the carcass lie on the ground unburied for a while, its torso slowly picked apart or trampled, and then the stream formed? I would guess the first scenario is more likely, since the bones seem to run through several strata. But again I’m not an expert in taphonomy so I could be wrong.

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People often wonder why the fossil record isn’t more complete, and why we get so excited about the discovery of even partially complete skeletons. This camel demonstrates one of myriad taphonomic processes, one of the many ways that earth, water and time conspire tear the past asunder.

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Osteology everywhere: Graffiti

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…)

Osteology everywhere: Pollicem verte(b)r(a)e [Latin puns are hard]

I just got back from the meetings of the European Society for the Study of Human Evolution in Florence. As you can guess, bones and genes and anatomy and apes and biomechanics and energetics and everything were on everyone’s minds. Even in the midst of an unseasonal surprise typhoon of lunch time ice:

Ambush of hail.

Aw hail no.

Along the way, I passed a gift shop window and this book cover immediately caught my eye:helert

No, it’s not an ancient Roman gladiator’s helmet. It’s clearly a lumbar vertebra, probably of some quadruped. We’re looking down onto the top (or front of it) from the cranial view. The body or centrum is the rounded part toward the bottom of the picture, the short transverse processes jutting off to the sides. The spinous process, pointing toward the top, is even thick and blunt distally as is characteristic of lumbar verts. Here’s a comparison:

Middle lumbar vertebrae, from the cranial view (modified from Figs. 3-4 of Moyà-Solà et al., 2004). 0=modern baboon, A=Proconsul nyanzae (KNM-MW 13142-J)(B) P. catalaunicus (IPS-21350.59). (C) Cast of Morotopithecus bishopi (UPM 67.28) from Moroto (Uganda). (D) D. laietanus (IPS-18000) from Can Llobateres (Spain). (E) Pongo pygmaeus

Middle lumbar vertebrae of various Miocene apes (A-D) in cranial view (modified from Figs. 3-4 of Moyà-Solà et al., 2004). 0=modern baboon, A=Proconsul nyanzae (KNM-MW 13142-J), B=Pierolapithecus catalaunicus (IPS-21350.59), C=Morotopithecus bishopi (UPM 67.28), D=Hispanopithecus laietanus (IPS-18000), and E= modern orangutan.

Modern apes use an upright posture more frequently than living monkeys, who are quadrupedal. An anatomical correlate of these postures is the position of the transverse processes. Compare the baboon (0 in the figure above) with the orangutan (E). In the monkey the transverse processes come off the sides of the centrum (below the horizontal line), while in the orangutan the processes come off the pedicle further back. In your lumbars the transverse processes arise a little bit more toward the back than in the orangutan.

This is a pretty characteristic pattern, meaning that we can reconstruct the habitual posture of an animal based on a single bone – even just part of a single bone as in the case of Hispanopithecus (D, above). Proconsul nyanzae (A), dating to around 19 million years ago and therefore one of the earliest apes, has a monkey-like lumbar vert; the rest of its skeleton is monkey-like and so we think many of the earliest apes moved around like modern monkeys. In contrast, Morotopithecus bishopi (C), at 20.6 million years ago, is also one of the earliest apes but has a more modern-ape-like lumbar. And so with Pierolapithecus and Hispanopithecus.

The vertebra gracing the cover of our gift shop book is clearly more monkey-like, presumably from a simian who long ago walked on all fours across the blood-soaked floors of a cacophonous Colosseum.

Osteology Everywhere: Astana

I don’t usually write about the moonscaped city I’ve lived in for the past 2 years, but I stumbled upon some osteology today worth sharing. Astana is an anachronism. The capital of Kazakhstan for only 16 years, the city sports a futuristic skin, glistening with Kazakh cultural heritage and thrust upon a Soviet skeleton. This place is a palimpsest, embodying the country’s rich history and spirited aspirations.

Astana’s modern and edgy facade encroaching into the steppe and swamp on the city’s southwest outskirts

I live and work on the Left Bank of the Yesil River. Under constant development, the Left Bank often falls short of the metropolitan feel the city’s striving toward. But hop over to the other side of the river to the Right Bank, and Astana takes on a much more urban feel. This is the older part of the city (though this is still relatively young), and as such there are more people and there is more stuff.2014-06-28 13.07.46Now, to combat my summer antsiness, I recently acquired a bicycle (velosiped in Russian), not so much for exercise but to explore this colorful city. (All the pictures in this post are a result of this acquisition) This morning I rolled onto what turned out to be Eurasian National University, and was surprised to find myself besieged by bones:

BONES!

Unlike other Osteology Everywhere posts, where I think I see bones in quotidian sights, these objects are indeed bones.

In the spirit of the bone quizzes on Bone Broke Blog, I challenge you to tell me what these bones are. There are four of a kind on the red and white tiles in the foreground, and a taller one stood upright on a sphere in the background. Can you identify 1) what bone each of these is, and 2) the animal they come from? Bonus points if you can specify which side of the body. Here are some other views:

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Finally, although only mildly related but because it’s totally badass, here’s a picture of lightning I snapped during a storm last week:2014-06-20 21.57.37

 

 

Osteology everywhere: A sign I might have a problem

Over the holiday break I was working at a cafe, and was shocked to find the upholstery besprinkled with bones. Looking at this seatback, can you tell what kinds of bones, and from whom, adorn this food establishment?

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Of course there’s no one right answer, but what I saw were the undeveloped shafts of infant limbs. Infants?! Mildly morbid, mayhap, but one of the distinguishing features of juvenile limb bones compared with adults is that babies’ epiphyses (joint ends) are not fused to the shafts. Observe:

From left to right, human perinatal humerus, femur and tibia (from Scheuer and Black, 2000).

From left to right, human perinatal humerus, femur and tibia (from Scheuer and Black, 2000).

Each of the newborn bones pictured above is comprised of a shaft (diaphysis) that flares proximally and distally into a ‘metaphysis.’ In adults, the epiphyses are completely fused to the metaphyses, but in juveniles the epiphyses are separated from metaphyses by a growth plate made of cartilage. Different epiphyses tend to fuse at characteristic ages, and when fusion occurs bone growth ceases.

Functionally, this cartilage growth plate allows the bones to increase in length, as multiplying cartilage cells are replaced by bone cells. Because the epiphyses of different limbs fuse at different times, this means that limb proportions change subtly over the course of growth. Practically, this means that if an archaeologist (or forensic scientist or paleontologist) finds a limb shaft with unfused ends, he or she can estimate the age at which the individual may have died:

Same bones in same order as in previous figure (also from Scheuer and Black, 2000)

Standards for epiphyseal fusion. Same bones in same order as in previous figure (also from Scheuer and Black, 2000). “A” refers to the age (years) when the epiphysis firsts appears, and “F” to when it fuses to the shaft.

So if we assume the bones in the second figure are from the same person, we see a humerus, femur and tibia with completely unfused epiphyses. If we refer to our aging standards (third figure), we can see that the first epiphysis to fuse is the proximal humerus, between 2-6 years, and the next epiphyses to fuse are the distal humerus and femur head/proximal tibia between 12-14 years. So we could conclude that this poor kid was certainly younger than 12, years, if not even younger than 2 years. Again, having more of the skeleton (especially jaws with developing teeth) would help us make a more precise estimation.

Baby bones all over the place?! Shame on you, Panera.

GET THIS BOOK: Scheuer L and Black S. 2000. Juvenile Developmental Osteology. Academic Press.

Osteology everywhere: Muffin tops

It’s become challengingly chilly here in Astana and my days of running outdoors are fading into memories redshifting into oblivion, so last weekend I went ice skating instead. Pulling off certifiably Scott Hamiltonian moves, I espy my silhouette and what hominid face is staring back?

That’s, right, Australopithecus boisei (right). Of course they’re not identical, but then they don’t really have to be when you see Osteology Everywhere.

But then again, when you’ve been doing this too long, you start to see Paleontology Everywhere, too. The shadow also reminded me of a time a few years ago, when we were picking through bags of backdirt at Dmanisi, foraging for micromammals, passing pachmelia and time with trivia. Someone posed the riddle, “What did one muffin say to the other muffin?” To which I responded:

Osteology everywhere: Pelvis has left the building

The vernal awakening has brought rain to Ann Arbor, and right on here on main campus I spotted the rain-splotched silhouette of an articulated human pelvis (left).

Check out those short and flaring iliac blades, and the shortness of the ischium. These features are associated with repositioning key muscles for walking and running on two feet, and are very unlike what is seen in the four-legged, suspensory climbing apes.

But just how ‘human’ are these features? The crushed pelvis of Oreopithecus bambolii, a ~8 million year old fossil ape from Italy, has somewhat human-like short ilia (left). This pelvis also has weak anterior inferior iliac spines (Rook et al. 1999), which anchor the hip/trunk flexor muscle rectus femoris, and are allegedly a developmental novelty seen only in hominids (Lovejoy et al. 2009). These traits have led some to claim that Oreopithecus was a hominid, or at least bipedal. Without getting into that debate, I’ll just say that seeing these ‘bipedal’ features in this late Miocene ape’s pelvis weakens the case that their presence in Ardipithecus ramidus indicates a unique connection between Ardi and later, true hominids like australopiths.

UPDATE: Check the comments for notes on the Ardi and Oreo fossils from someone who’s actually studied them (I myself have only seen pictures and read about them).

ResearchBlogging.orgReferences
Lovejoy, C., Suwa, G., Spurlock, L., Asfaw, B., & White, T. (2009). The Pelvis and Femur of Ardipithecus ramidus: The Emergence of Upright Walking Science, 326 (5949), 71-71 DOI: 10.1126/science.1175831

Rook, L. (1999). Oreopithecus was a bipedal ape after all: Evidence from the iliac cancellous architecture Proceedings of the National Academy of Sciences, 96 (15), 8795-8799 DOI: 10.1073/pnas.96.15.8795