Ossamenta

In about two weeks time I'm off to London for the Postgraduate Zooarchaeology Forum's conference. Since I'm neither a postgrad nor a PhD student I won't give a talk, but instead I will sit and listen to several interesting talks and take copious amounts of notes. It will be such fun!


- A new Viking Age female figurine has been found! Just as with the 2012 find of the figurine with sword and shield, there are lots of dress details which I'm sure will delight any authenticity minded Viking Age re-enactors.

- Keeping in the small figurine theme: A 13th century Limoges enamel Madonna found buried under Danish church floor.

- If you ever wondered where a penguin's knees are, look no further.

- The Walbrook Discovery Programme has a blog post up on animal remains from Roman butchery.

- "Let's just say an unbearable smell was emitted" - how to reduce a blue whale to a pile of bones. I'm so impressed at the size of those vertebrae! Although I'm glad I wasn't there in person, and that internet doesn't (yet) do smell-o-vision...

- One of the advantages of a British Museum membership is tickets to members' lectures. Luckily for us who a) aren't members or b) couldn't go, Mary Beard's Pompeii lecture is now online. Thanks BM!

Rain/heavy rain was forecast and consequently my plans for the weekend involved me, sofa, good book, embroidery and not going outside more than I absolutely had to. However, that Friday evening I found out that there was a temporary exhibition at the Natural History Museum in Tring on a new bird book. And it turned out that Saturday was my only available day before the exhibition closed…

Nothing for it. Off to Tring.

The exhibition showed 15-20 exquisitely drawn bird skeletons, often ”in life” rather than merely standing up, three mounted skeletons and the book. I had said to myself that if I liked the book I would put it on my Christmas wish list, as it was £35, and it would be far better if someone else spent that money :-) . But after a quick glance through the book in the shop, I decided that instant gratification was the better choice. After all, Christmas is a long time away, and the book could go out of print. If it had only been anatomical drawings, I probably would have passed. But the text is highly informative on how bird behaviour, appearance and posture are influenced by their anatomy, and vice versa. As the author says, it’s not a book about the inside of birds, it’s about the outside of birds.

John's review post is full of info and pictures, so instead of repeating most of this, I will merely link to his blog. He didn't include my favourite drawing, a diver under water, so I'll post a photograph here. Unfortunately, what with the lighting and placement of the drawings, this one in particular was very hard to photograph, as it all reflected back in the glass. You can even see parts of the emergency exit sign reflection in the lower left corner of the glass.


Diver (that's loon in the US) under water, with a fish and waterlily leaves seen from below in the upper right corner.

In the comments to the strangest animal bone-post, I mentioned bird quadrates. And since I doubt most readers will immediately get an image in their minds from that word alone, I thought I’d add a picture.


Quadrates from chicken (left) and duck (right). This bone attaches between the skull and the mandible in birds and reptiles.

The quadrate is one of those bones that are rarely illustrated, so when you find them it’s not easy to immediately attach them to a species or to a specific element group. Before I learned to recognise them for what they were, I often put them in the fish bones bag.

Here is a good photo of the quadrate in situ.


And in my hunt for cool zooarch blogs, I came across Zygoma, which mostly consist of very difficult mystery object posts. The reason I find them very difficult is that these specimens come from all over the world - it's not too difficult to identify the type of animal, but which of the 13 different otter species is the one in the photo? *tears hair*

Sometimes sexing birds can be very easy:


Sometimes it is difficult:


While there can be size differences between males and females of the same species, there is often an overlap, which makes it difficult to carry out a reasonably secure sex estimation. If you have a large sample, you can hopefully get two (somewhat overlapping) bell curves, but bird bones are rarely found in such quantities*.

From a European point of view**, normally there are two ways of sexing birds: presence of spurs (only on galliforms, i.e. chicken, pheasant etc) and presence of medullary bone. Medullary bone is formed in the bone shaft cavity on female birds when they’re laying eggs. This acts as a calcium buffer for the egg shell development. The level of medullary bone can vary, from a millimetre lining on the cavity to a fully filled bone shaft, probably depending on where the hen was in the egg laying cycle, and/or how calcium rich the feed is. Medullary bone are most often found in the femur and tibiotarsus (the thigh bone and the drumstick bone). Medullary bone sexing has two major drawbacks: It can only be observed in fragmented bones. Since bird bones normally are rather small, there is little need to portioning them by cutting them in two, as is done with bones from cattle, sheep and pig. It is therefore likely that we miss several egg laying hens in bone assemblages. Secondly, the method only counts egg laying hens, possibly not the preferred animals to slaughter.


Medullary bone inside a fowl femur


Close-up of medullary bone

Spurs are more straightforward when it comes to sex estimation, even if they only appear in a few species. However, just as with horse canine teeth, occasionally females have them too. The bone part of the spur forms separately and fuses with the bone shaft at six months of age, although this is very variable.


Male and female fowl tarsometatarsus


Sometimes spurs have been cut off, either as a way to castrate the fowl (or, possibly to prevent fights within the flock) or to make it easier to tie metal spurs on for cock fighting. Not that that was necessary, cock fighting did and does happen with "natural" spurs too. Sometimes a predominance of male fowl in an archaeological assemblage has been interpreted as occurrence of cock fighting, although, at least for the Roman period, cocks would also have been the preferred sex for sacrifice.


Medieval cock fighting, from MS Bodleian 264, fol. 50r.

Conclusion: bird sexing is much easier with live ones!

(read more? Dale Serjeantson, 2009, Birds, Cambridge University Press.)


*: Not only are there normally less chicken on the menu than cattle, sheep and pig, but the thin bird bones are easily destroyed in the soil.
**: I don’t have the experience to say whether non-galliform birds on other continents have sexually distinct skeletal elements or not. If some of my readers know, please tell me!