Bone Quiz 12

This morning Antonio, one of the museum security guards, brought his young daughter and niece down to the basement so they could see me at work . They were both about 8 to 10 years old, proper Jiennense girls attired in brightly-colored summer dresses and clean shoes, with their long hair pulled back from their faces with head bands. Antonio explained that this visit wasn’t at his behest; the girls had both wanted to come down to see the sort of work I was doing. Unfortunately I didn’t have any primary burials laid out, but I was able to show them some of the loose dentition I’ve analyzing lately. I let them tap on the molars, hold my comparative specimens, and peer at the multiple crania that I currently have adorning the countertops. Antonio’s daughter kept looking around the room with the widest eyes I’ve ever seen, but started and then smiled whenever I talked to her.

While curiously examining my equipment, Antonio asked me if my prized possession, White’s Human Bone Manual, was about the “human body”. His niece jumped in to answer: “No, por que en Ingles, cuerpo es….oooman baahdy” she said, haltingly but on point. I grinned at that, since it was the most English I’ve heard from a Jaén native. “Si, muy bueno” I replied. After a few more minutes they took their leave – “It’s very interesting work” I said, in faltering Spanish, as they departed. At that, the small girl with the enormous eyes grinned.  “¡Que chulo!” I heard one of them exclaim as they were climbing up the stairs, the Spanish equivalent of  saying “How wicked!”

Their visit made my morning. In a time when being a woman in science is hard enough, and more and more research is unveiling the significant role gender plays in shaping our professional choices and experiences, it was refreshing to meet two young girls who wanted to venture down to a dirty basement to meet a strange, pale foreigner – rather like Bilbo and Sam venturing into Gollum’s cave, now that I think about it – to see what all the fuss was about human bones.

In the spirit of continuing that enthusiasm for learning , I’ve laid out a new bone quiz below. The usual rules apply:

1. Human/Non-Human;

2. Adult/Juvenile;

3. Bone;

4. Side;

5. Name the telling feature highlighted in first photograph.

The scale in the photos is 3cm, and I’ll post answers soon. In the meantime, I hope you are all having a cool July, replete with air-conditioning, beer, and limited loose dentition!

Posterior View (Superior ^)

Posterior View

 Anterior View (Superior ^)

Anterior view

Superior View (Posterior lower)

Superior view

Inferior View (Posterior lower)

Posterior view

Image Credits: All images were taken at the Museo de Jaén in summer 2013 and 2014.

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Skopje

[Explanatory Note: I'm going to be doing a lot of travelling in the next six months, and  I'll occasionally post a travel essay that has nothing to do with osteology or bioarchaeology. These will be tagged under a new "Travel Essay" category, so they'll be easy to bypass if you're only looking for strategies for siding the calcaneus or palpating the anatomical snuffbox.]

Renfe view

I’m on a train that’s barreling south through the sun-drenched plains of Castilla La Mancha. I’ve been up since three in the morning and a persistent, exhaustion-fueled hunger is starting to kick in; it feels like a widening hole is slowly gnawing into the soft tissue between my stomach and my spleen. As is typical of this summer, I’ve spent much of the past week travelling: on trains, cars, taxis, buses and airplanes, to get from the somnolescent, sun-drenched Andalucían city I currently call home to the mountain-ringed Macedonian capitol of Skopje. This trip marked my second visit to the region, and as my flight from Rome began its descent I realized that I had forgotten how rugged and stereotypically Balkan the surrounding terrain actually is. I mentioned to one of my friends that I don’t think of a place as a real city unless it has a neighboring mountain topped by either a castle or a cross. Skopje meets my criteria, with the looming, cross-brandishing Vodno a constant back-drop to the hum of Eastern European urban bustle. Many of the tiny flourishes of post-Soviet life reminded me persistently of my childhood in the Balkans, from the angular spool-shaped cement blocks unevenly arranged into sidewalks, to the tiny, anachronistic Trabants and Škodas zooming through the streets, and the abashed, amused pleasure the local populace seems to feel at foreigners mangling their language – whenever I attempted even the briefest  “fala” or “smetka” after speaking English, shop keepers giggled and bartenders bit back their smiles.

Vodno The food, however, is what always does it for me. Simple Shopska salads of roughly chopped tomatoes and cucumbers topped by mountains of a shredded sharp cheese called cyrene, the ubiquitous half-bitter, half-sweet roasted peppers that appear in everything, and, of course, the yogurt. Macedonian yogurt is plain, sour, and so fluid that everyone drinks it rather than eating it with a spoon, whether it comes in a bottle or the smaller, pull-top containers we are more familiar with in the West. While your first sip is bracingly cold and sour, the flavor and texture quickly become addictive in the unrelenting heat of Macedonian July, especially when drunk as an accompaniment to the products of Macedonian bakeries. Burek and banichka, differently shaped variants on a cheese pastry theme, are my favorite foods to eat in this part of the world. Greasy, buttery layers of filo dough are layered on top of each other, rolled around chunks of crumbly goat or sheep’s cheese and then shaped into concentric rings of pastry and baked in a ceramic or metal oven, which is traditionally nestled in a constantly banked mound of coals. Bakeries are found all over the streets, selling both burek and the round circles of sesame-studded bread that I remember vividly as being my favorite mid-day snack in Greece, where it is called koulóuria, the lightly sweetened, chewy bread punctuated with the toasted, nutty flavor and gritty crunch of the sesame seeds.

Banichka

Burek only costs 40 or 50 denar if you buy it at a small local shop, around a dollar for a substantial amount of flaky, achingly greasy bread. It’s handed to you hot from the case, wrapped in plain gray paper that immediately becomes saturated with grease, and slid into a filmy plastic bag along with a narrow rectangular receipt only a little wider than the width of your thumb. Receipts are proffered for even the smallest of purchases, printed out on large hand-calculators that flank the cash register in any respectable establishment. On this trip I was also introduced to kiflochki, long breadsticks that are soft only when eaten fresh out of the oven. They are traditionally made with so much salt that they have to be dipped in yogurt to be palatable. Demolishing a paper-wrapped bouquet of them at six in the morning, purchased fresh from a road-side Albanian bakery, was a gustatory highlight of the trip.

Culturally, one of the things that struck me most about the city was the linguistic versatility of its populace. It seemed like everyone in Skopje, from the cashiers to the cab drivers, spoke English. What’s more, they didn’t appear offended or put out at having to use it. I felt none of the low-grade linguistic hostility I’ve witnessed in other European capitals, where my American-ness seems to be taken as a deliberate and uncouth insult, like belching in public or taking off a reeking pair of shoes on a train. In contrast, the denizens of this Macedonian city seemed gently amused by my blundering foreign presence, treating my missteps with smiles rather than scowls. From the old women who kissed my cheeks and patted my face at the wedding, to fellow guests who taught me how to dance the oro, undeterred by my clumsy steps and sweaty hands, all I felt was overwhelming hospitality.

Downtown SkopjeI must admit, in these sorts of contexts its hard not to feel embarrassed by my monolingual vocabulary. This summer I’ve met Japanese scholars with doctorates from German universities who speak English with unerring, American-accented fluency, and German archaeologists who can convincingly wheedle Spanish hostel concierges into finding an extra room during a the chaos of a flamenco festival (and then turn around and explain how they did it to me in English that is just as capable). The wedding I just attended was a Belgian/French-Canadian/Macedonian extravaganza, where everyone had to speak at least two languages just to handle the quotidian politics of familial communication. Even now, the young painter from Barcelona, sitting across the train table from me, is devouring a George R.R. Martin tome – in English. “Do you understand any of that?” another seatmate asked her in Spanish at the beginning of the journey. “Oh, I get most of it” she answered, “though a few things get lost”.

On that note, it is probably time to burrow back into my Andalucían life, and attempt, once again, to apply myself to the slow, exhaustive process of communication. Or, as I would so eloquently put it in my fluid, graceful Spanish “Estoy ya…no,no, todavía…aprendando la idioma, y por favor ¿puede usted hablar un poco mas despacio? No, no desPAcio. ¿Lentamente? ¿Menos rapido? Lo siento, no es importante, no es importante, no pasa nada, no se preoccupe.”

 

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Palpable Anatomy: How to identify and side an isolated zygomatic process

A few weeks ago I posted  a bone quiz that some of my friends have been finding a little trickier than usual. My hints were that:

(i) This feature is notable for arching laterally, and                                                                                   (ii) It is one that preserves well in archaeological contexts.

You can see one of the original images in the photo below, shown with a 3cm scale.

Medial View The fragment in question was the zygomatic process of the temporal bone, a feature that makes up part of the zygomatic arch that between the temporal bone and the malar bone. This portion of the temporal bone is highlighted in bright blue in the following diagram:

Zygomatic process highlighted in blue

The reason this is also a palpable anatomy post is because it’s an easy feature to feel on your own skull. Press your fingers along the superior and posterior portion of your cheek bone, and nudge them towards your ear. You should feel a protruding ridge of bone running in an anterior to posterior direction. Your fingers will slide off above and below this ridge.  In the photo below, I’ve lined my fingers up along the zygomatic arch – if you put yours in the same approximate location just in front of your ear, you’ll be able to feel the feature as well.

Palpating the zygomatic arch

The reason I find the zygomatic process of the temporal bone so easy to recognize is because, to me, it looks like an arm. I see the jagged edge of the concisely named zygomaticotemporal suture as the fingers on a hand, and the chunkier, more posterior portion of the bone as the meatier forearm and elbow, as you can see in the convincingly organized photo below.

Identifying and siding an isolated zygomatic process

Once you visualize this parallel, the complete bone is easy to orient. Remember that the convex side is lateral, the thickest and roundest portion of the bone is posterior, and the sutural border is anterior. To double-check yourself all you need to do is hold out your own forearms and compare the orientation and curvature of the bone to the orientation and curvature of your upper limbs. (On a side note, when left to my own devices in lab I always look like I am doing some sort of bizarre, slow-motion yoga or interpretative dance, flipping my palms, stretching out my arms , palpating my mandible, etc., etc. It’s a good thing there’s only one other person working in the museum basement this summer).

Slide2These tricks will allow you to orient even the most fragmentary portion of this feature.  If you don’t want to look as if you’re embracing a ghostly companion, simply place the bone in front of you so that the more concave side is facing down and the more convex side is facing up. The thinnest, straightest edge is superior, while the more angular border that likely has two different, identifiable flattened surfaces, is inferior. In this position, the jagged suture for the zygomatic bone points to the side the bone is from.

To test your skills, orient and side the fragmentary zygomatic processes shown in the following two photos. Pay attention to (i) the superior-inferior height of the fragment (is it ‘chunkier’ or more gracile?) (ii) whether the side shown is concave or convex, and (iii) the location of the zygomaticotemporal suture, if present.

Answers are posted below the jump after the image credits, with the fragments shown articulated with larger portions of temporal bones, and sides indicated in the alt text.

Fragment A: Two views, easier (Note that the fragment was flipped horizontally between the top photo and the bottom photo).

Fragment A

Fragment B: One view, more difficult.
DSCN1064
Image Credits: First image of temporal bone highlighted in blue found here at studyblue.com. Second image of temporal bone found here. All other photos were taken at the Museo de Jaén in summer 2014.

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ANSWERS

 

 

Fragment A:

This is a LEFT zygomatic processThis is a LEFT zygomatic process

Fragment B:

This is the posterior portion of a RIGHT zygomatic process

Posted in Osteo Tricks, Osteology, Palpable Anatomy, Siding Tricks | Tagged , , , | 1 Comment

A Travel Agency for Osteologists…

Skopje, downtown This past week I was in Skopje for a friend’s wedding. While exploring the city center (by which I mean searching out and sampling as much banichka as I could get my hands on during my limited time in the Balkans), I glanced across the street and realized I’d been planning my summer travel all wrong. Why have I been using Expedia and Booking.com when I could have been using Fibula Air Travel Agency!?

Fibula Air Travel Agency No wonder my itineraries have been so disorganized.

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All worn out: using dental attrition to estimate age

Dental attrition

I was recently working on the methods chapter of my dissertation (I’ll pause so that you may lever your jaw up off of the floor – “JB? Working? On her dissertation?”) when I stumbled upon a fantastic old school anthropology quote that struck my fancy. I’m currently mired in the midst of my section on adult aging, and given the fragmentary nature of many of the Marroquíes Bajos remains, traditional techniques that rely on cranial sutural closure, the auricular surface of the os coxa, or the pubic symphyseal face are rarely useful. However, I do have a lot of teeth, over 750 in the two mortuary locales I’ve analyzed so far. Accordingly, I’ve been carefully scoring dental attrition (a more fanciful term for the enamel wear that gradually exposes dentin over the course of an individual’s lifetime) for all teeth, in the hope that this will prove informative about the age distribution of my mortuary population. However, as AEW Miles pointed out over 50 years ago, there are other things besides age that can affect the severity of dental attrition:

It is usual to attribute the greater degrees of tooth wear to the nature of the food; namely to food of fibrous or tough character requiring much chewing, or to contamination of food with abrasive substances such as sand, soil or ashes. Quite apart from these considerations, however, chewing habits and conventions in early times are likely to have been quite different from those of the present day. Those living less sophisticated lives, with few man-made pleasures, both in the past and the present time, would be inclined to spend more time savouring the act of mastication. This could lead to increased wear in the same way that habitual tooth grinding, as a nervous habit, leads to marked wear of the teeth” (17).

The reason I am so enamoured of this quote is because as a graduate student, I devote an inordinate amount of my time to “savouring the act of mastication”, both because I need some form of ready bribery to motivate myself to write my dissertation, and because I am in a part of the world where the food is abundant and delicious. Since I’m also as unsophisticated as all get out, I really do meet all of the requirements necessary to be true “savourer of mastication”.

Anticipating "savouring the act of mastication" :preparing tostada in Madrid, summer 2013

Anticipating “savouring the act of mastication”: preparing tostada in Madrid, summer 2013

Despite Miles’ slightly patronizing stance when it comes to the joys of chewing, he made significant contributions to the development of standards for aging individuals based on dental attrition. Miles came up with his strategy in response to a thorny bioarchaeological problem. He had access to around 190 individuals from an Anglo-Saxon burial site at Breedon-on-the-Hill in Leicestershire, a sizeable sample for an interested osteologist. The catch was that these individuals were represented solely as skulls or fragments of skulls, and “owing to circumstances associated with advancing quarrying operations it was not possible to recover the post-cranial skeletons”(1962:881)….Which I take is archaeological parlance for “the skeletons themselves have also been quarried out”.

In order to investigate any aspects of demography from this 7th- 9th century A.D. population, Miles had to be clever, and invent a way to assess age without having any access to post-crania. Working from a simple observation about dental eruption schedules, Miles was able to come up with a defensible strategy. His logic was simple, but elegant, and can effectively be broken down as follows:

1. The timing of mandibular molar eruption is relatively predictable, with M1 erupting at around 6 years of age, M2 erupting at around 12 years of age, and M3 erupting at around 18 years of age;

2. It follows that if an individual has their M1, M2 or M3 erupting, you will be able to produce a fairly narrow and accurate estimate of age for them. Miles was also able to rely on Schour and Massler’s (1941) standards for dental development, which provided tight estimates of age for subadult individuals using the development and eruption schedules of all the teeth, not only the molars;

3. Accordingly, the degree of wear on the dentition of subadult individuals can be compared to the individual’s estimated age to produce an approximate rate of wear. For example, if the M1 erupts at 6 years of age, and the M2 erupts at 12 years of age, the M1 in an individual whose M2s are just erupted will have wear showing six years of functional age.

Second molars erupted....

4. The functional age of a specific tooth can then be added to the age of eruption for that tooth in order to produce an age estimate for the individual in question. So in the case above, with an M1 showing six years of functional age, you would add: 6 (functional age) + 6 (age of eruption of tooth class) to produce an age estimate of 12 years.

Maxillary wear - complete half arcade5. The rates of wear calculated from subadults of known age-at-death can then be used to extrapolate the functional (and then chronological) age of older individuals from the same population, assuming that rates of wear are consistent within the population.

Importantly, during his data collection Miles observed that not all classes of molars wear at the same rate. In particular,“…it takes only six years for M1 to reach a state of wear that it takes M2 and M3 respectively six and a half and seven years to reach…[so]…if a third molar is found which matches a first molar which shows 18 years of functional age, by a simple calculation it is possible to say that the third molar is 21 years of functional age”(1962:20). By relying on the wear gradient 6:6.5:7 (M1:M2:M3), starting with the wear-scores of sub-adults with known ages-at-death, Miles was able to estimate the age of older individuals based on the relative amount of wear on each category of tooth.

The basic principles underlying the Miles method continue to be used to this day by bioarchaeologists. Wear is assessed visually,and the   the amount of visible dentin is scored qualitatively for the teeth of the individual you are examining. Osteologists often use visual depictions like the Brothwell chart shown below as a benchmark against which to compare the dentition they are evaluating. (I prefer to use the modification of the Scott system outlined in Standards, because I always have a copy of Standards on hand).

Brothwell's system for scoring dental attrition

Finally, while the Miles method is a useful strategy for estimating adult age using dental attrition, it has two significant difficulties. First, it relies on samples which contain a large number of subadults with relatively complete dentition. If your population stems from the 7th-9th century AD in England, you’re all set, but if you’re working on a more fragmentary Copper Age sample in, say, Iberia, this will prove a little bit more problematic.   Second, Miles based his eruption times on a combination of data derived from a slightly modified Schour and Massler chart (1941), which was collected from a modern reference population, and padded it out with additional data collected from contemporary subjects. This reference data-set is, as a result, not entirely commensurate with prehistoric, pre-industrial populations who would have consumed different types of foods and led different types of lives than modern populations.

M1, M2 and M3 all fortunately present

Fortunately, Gilmore and Grote have created a modification of the method to address these problems; one that applies specifically to samples “where juveniles and post-cranial elements are under-represented” (2012:182), with estimates of molar eruption times deliberately derived from non-industrial populations.

The Gilmore and Grote modification of the Miles method calculates the average difference in wear between an individual’s M1s and M2, then sums these values for the sample population to establish a mean and standard deviation for the sample M1-M2 difference. The wear score for each class of tooth is produced by averaging all scores available for both maxillary and mandibular categories of the same tooth (e.g., for a given individual i, the M1 wear score is the average score of all quadrants for the LM1, RM1, LM1 and RM1). All individuals with extremely low M1 wear scores are excluded from calculating the population wear rate, to avoid producing artificially constrained values based on the small M1-M2 differences that would result from very recently erupted M1s. After winnowing the sample, average wear per year is calculated for the sample population by dividing the population average difference by the number of years between the eruption of the first and second molars. Once the population wear rate has been calculated, Gilmore and Grote follow Miles’ basic strategy of adding the age of eruption to functional age to estimate age at death.

You need wear scores for all the individuals in your population in order to use the Gilmore and Grote modification of the Miles method (so as to be able to calculate the average wear per year for each tooth category). Accordingly, I won’t be able to use this to estimate the age of the adults in the Marroquíes Bajos mortuary population until the end of my dissertation research, but I will provide a brief update and, I hope, a discussion of the basic demographic structure of my population.

Until then, I’ll have to figure out something else to sink my teeth into….see what I did there?


References

Buikstra, J. E. and D.J. Ubelaker.  1994    Standards for Data Collection from Human Skeletal Remains, Edited by J.E. Buikstra and D.J. Ubelaker. Arkansas Archaeological Survey Research Series No.44, Fayetteville.
 
 
 
ResearchBlogging.orgGilmore CC, & Grote MN (2012). Estimating age from adult occlusal wear: a modification of the miles method. American journal of physical anthropology, 149 (2), 181-92 PMID: 22763560
 
 
 
ResearchBlogging.orgMiles AE (1962). Assessment of the Ages of a Population of Anglo-Saxons from Their Dentitions. Proceedings of the Royal Society of Medicine, 55 (10), 881-6 PMID: 19994189
 
 
 
ResearchBlogging.orgSchour, J., and M. Massler (1941). The development of the human dentition Journal of the American Dental Association, 1153-1160
 
 
 
As a note, Schour and Massler’s seminal article on the development of the human dentition is available open-access online, here, as part of the Journal of the American Dental Association  Centennial series. Download it and add it to your library!

Image Credits: Image of Brothwell’s scoring system found here.

Photo Credits: All photos were taken at the Museo de Jaén in summer 2014 and are used with the permission of the museum.

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Bone Quiz 11

Mezquita, from across the riverI went to Córdoba last weekend, to meet up with an old friend from fieldwork in Portugal, and, as  it turned out, to unintentionally attend an all-night flamenco festival. I know, I know  - it probably seems like all I do is gallivant around southern Spain, eating tapas, drinking cervezas, and lounging about in the copious Iberian sunlight. However, I’ve been highlighting these sorts of adventures rather than my daily routine, a tendency which glosses over some of the more mundane aspects of bioarchaeological data collection. For example, while the view of the Mezquita, above, is typical of Andalucia’s architectural charms, most days I actually spend my time looking at views like this:

Ah, bones.My one daily respite involves the twenty minutes I stumble blearily upstairs to eat my sandwich and bask in the small square of sunlight decorating the back-building steps of the Museo de Jaén.  Accordingly, any opportunity to wander father afield (e.g., out of the basement) and explore a little bit more of Andalucía is always welcome.

Anyhow, I’ve visited Córdoba twice over the past two summers, and I have noticed that it’s characterized by arches of all kinds, from the great arcing supports of the Roman bridge over the Guadalquivir:
Roman Bridge, Córdoba

to the mesmerizing red and white arches of the Mezquita:

The arches, summer 2013

Walking through the Hypostyle Hall is like wandering through one of M.C. Escher’s fever dreams; the arches lend the Hall an air of architectural infinity, and the mosque seems to expand ever outward as you move through it. I didn’t have time to visit the Mezquita again on this brief trip, but if I ever head to the city again I’ll gladly pay 8€ to spend an hour gawking at its majestic columns.

The long and winding point to this post is that the ubiquitous Córdoban arches reminded me of a specific portion of a bone that I’ve been finding frequently of late. I have a sneaking suspicion that these preserve well archaeologically because they’re so compact and durable – much like Classical Roman bridges in southern Spain. Rather than arching vertically, they arch laterally, but the fragments always have a distinct curvature that is impossible to miss. So, without further ado:

1. Human/Non-Human;

2. Adult/Non-adult;

3. Bone;

4. Name of this portion of the bone;

5. Side.

Lateral View

Lateral View (3cm scale)

Medial View

Medial View (3cm scale)

If you’re stumped, fear not. I’ve devoted an entire post to teaching you how to easily identify and side the fragment above, wherever you may find it. Answers will be posted after the jump shortly.

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Bone Quiz 10

IMG_20130516_155203
Andalucía is known for many things: its abundant tapas, its undulating hills blanketed in olive groves, and its inhabitants impassioned tendency to “comer sus palabras” or “eat their words” by condensing the Spanish language in strange and beautiful ways, particularly by lisping the letter z and dropping the letter s.  However, in the summers the region is also known for its intense and unbearable heat. There’s actually a town called Ecija, in the province of Seville, that is known as la sartén or the “frying pan” of Spain. Ecija, worrisomely, is only about 150km from Jaén.

la campesina, the rolling hills of olive fields that characterize this part of Andalucía
Despite the Andalusian propensity for furnace-like heat, June has been quite mild thus far. This week in particular has been beautiful, with highs in the 26-29˚C range every day. In celebration of the unseasonably cool weather we’ve been having, I present you with this week’s bone relatively easy, feature-based bone quiz. This bone is one that I came across in the course of some recent dissertation analysis. It was fragmented into several pieces, but refit perfectly.

To participate, you need to identify:

1. Human/Non-Human;

2. Element;

3. Features identified on the anterior and posterior portion of a fragment that should have allowed you to easily identify the element.

Anterior View

Anterior View

Posterior View

Feature Identification

 June will be the “month of bone quizzes” here at Bone Broke since I have been putting in lots of extra time at the museum to make up for an exciting trip I will be taking in early July. So, if you want to keep your osteological skills honed while you’re in the field , or if you want to learn about osteology instead of being at the beach, this is the month for you!

 

Answers after the jump.
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Slide10

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