Friday mystery object #326

Yesterday I was doing some work in the gallery of the Dead Zoo and found a specimen that needs a little light repair work to stick teeth back into sockets. I thought it might make an interesting object for you to have a go at identifying:


Any idea what this piece of mandible might belong to? It’s probably a bit too easy for some of the mystery object veterans, so please keep your suggestions cryptic and, if you’re in the mood, poetic.

Have fun!

Friday mystery object #325 answer(ish)

Last week I gave you the challenge of identifying this bit of bone found in a rockpool in Kimmeridge by 7 year old Annie:


It’s not the easiest item to identify for a variety of reasons. First of all it’s broken, only showing one end and probably missing quite a lot of the element. Next, the images don’t show all of the angles you might want to see and because the object is small the images aren’t as clear as you might like.

However, there are a few angles visible (see below) and there is a scale, so the main requirements to get an approximate identification are in place. I say approximate, because with something like this I think you really need the object in your hand where you can compare it to other material in detail if you want to make a confident identification.

Excuses aside, let’s take a look and see what it might be…

The first thing to note is that the bone is hollow with thin walls. This rules out fish, reptiles, amphibians and mammals (including humans jennifermacaire) – leaving birds.

Weathered mammal bones may have a void in the bone where the marrow would have been, but the cortex (outside layer) will be thicker and near the articular surface it tends to be quite solid.


Hollow bone = bird (usually)

Next, the articular surface of the bone is concave, which palfreyman1414 picked up on:

As far as I recall (mentally running through images in my head) both ends of the proximal limb bones in tetrapods have convex ends?

This is accurate, but while the proximal (near end) of the limb bones are convex, the more distal (far end) limb bones tend to have concave ends, so that helps narrow down what this bony element might be.


Concave articulation

For me the give-away here is the fact that there’s no ridge within the concavity of the articular surface, which means that it will allow movement in several directions – something that the bones of bird feet don’t really need, which is why bird lower legs,  feet and toes have a raised ridge inside the articular surface that corresponds with a groove in the other surface, keeping the articulation of the joint tightly constrained.


Articulation of Shag phalanx showing raised ridge

However, bird wing need to make a wider range of motion (at least in some species), so the mystery object is most likely the distal end of a bird radius (the ulna tends to have a hook at the distal end). This is the conclusion that Wouter van Gestel and DrewM also came to (joe vans should’ve stuck to his guns).


Distal articulation if duck radius

Identifying the species of bird is a lot more complicated. The size suggests a pretty big bird, which narrows it down and the locality in which it was found makes some species more likely than others. I took a look at the radius of some species that are commonly found on the coast, like Guillemot, Herring Gull, Duck, Cormorant/Shag and Gannet, Skimmer, Pigeon and I also checked out Chicken, since their bones are probably the most commonly occurring on the planet.


Gannet radius with some distinctive structure around the articulation

Many of the species I checked had quite a distinctive structure around the distal radius articulation, but the gulls, ducks and chickens that I looked at had fairly unremarkable distal radius articulations, making it hard to definitively decide what the mystery object is based on the images.


Herring Gull radius


Chicken radius


So with that somewhat disappointing conclusion I admit partial defeat, but I can say that it’s not from a Cormorant, Shag, Gannet, Pigeon or Guillemot. Sorry I can’t be more specific Annie!

Unfortunately that’s just how the identification game works sometimes… we’ll try again with something new next week!

Friday mystery object #325

This week I have a genuine mystery object for you passed on from my NatSCA colleague Holly, that was found in a rockpool in Kimmeridge by 7 year old Annie when she was out fossil hunting on the beach:


Any idea what this object could possibly be?

I don’t think there’s any need for cryptic clues this time, as it’s a proper challenge and I’d love to hear what you think it is and what it’s from. Have fun!

Friday mystery object #320 answer

Happy New Year everyone!

Last week I gave you this skull to identify from the collections of the Dead Zoo in Dublin :

King Vulture Sarcoramphus papa (Linnaeus, 1758)

I also included the label, since it offers an interesting taxonomic twist.20171228_163420.jpg

If there’s one principle that I hope I’ve managed to convey over the last eight and half years of doing the Friday mystery object, is that you should never fully trust the label.

For starters, the number NMINH:2006.12.1698 could be misleading, as it reflects the year the specimen was catalogued rather than the year it was acquired. To explain, the NMI uses a very sensible numbering system that starts with the collection (NMINH = National Museum of Ireland Natural History) the year of registration (usually the year of acquisition) which allows you to know which register to look in, followed by the lot number (a sequential number reflecting how many acquisitions have come in that year), followed by the individual object number (the sequential number of that individual item in a particular lot). This system can have additional numbers added if necessary, such as if a piece of an individual object is removed for sampling.

However, some older objects were not registered when they entered the collection and as such they get a number that reflects the year they were documented rather than the year they were acquired. In this case the specimen was registered in 2006, but purchased from an auction of the collections of van Lidth de Jeude who died in 1863, as Nigel (the Dead Zoo Keeper) helpfully pointed out in the comments.

If the specimen had been accessioned and numbered on entering the collection back in the 1860’s then issues with the name would be expected since taxonomy constantly changes and old names are often wrong, but because of the new label and the 2006 date, you’d generally expect the name to be more up-to-date. However, it appears that the information on an old label was directly transcribed without being updated.

This is relevant because the name Orogyps auricularis is what we call a junior synonym, which means it has been used to describe a species that already has an older valid name. When this happens the older name takes precedence. In this case, Orogyps auricularis is a name applied in 1867 by Degland and Gerbe to a species that had already been named Vultur tracheliotos  by J.R. Forster in 1796 and which is now placed in a different genus, giving the name Torgos tracheliotos (Forster, 1796) – where the parentheses around the author name indicate that the scientific name has changed from the original version that was published by Forster.

These taxonomic and documentation twists are however rendered redundant as soon as you realise that this specimen is from a totally different species. In fact it’s not really anything like Torgos tracheliotos the Lappet-faced Vulture:


Lappet-faced vulture

In fact, the only real similarity lies in the tip of the beak, which is a functional feature for tearing meat and which is convergent between the Old World Vultures and the New World Vultures. The Lappet-faced Vulture is an African species, while the mystery object has the distinctive deflection of the bill in the nasal region that indicates it’s a species from the Americas. This discrepancy in region was noted by palfreyman1414 and Gerard van den Brink.

Once you focus on the New World Vultures it becomes quite easy to make an identification, since there are only seven species and at 121mm this specimen is the third largest species after the condors – something easy to check on Skullsite. So well done to everyone who recognised the skull as belonging to the King Vulture Sarcoramphus papa (Linnaeus, 1758), especially palfreyman1414 who got there first.


King Vulture by Eric Kilby, 2008

As you can see, not only was the taxonomy very out of date for this specimen, it was also completely wrong, because it was misidentified 150 years ago. This is why you should never fully trust labels – they will often be wrong and if you base research on misidentified specimens, that will be wrong too.

Another mystery specimen next week!

Friday mystery object #320

I hope everyone had a lovely Christmas break!

This week I have another specimen from the Dead Zoo to identify – this one has an identification already, but the taxonomy is rather archaic and I think that once you’ve investigated the modern version of the name, you’ll realise that it’s wrong.



Skull length = 121mm


So, any idea what this name should actually be and, more importantly, what the identification actually is?

As always, you can put your thoughts, questions and suggestions in the comments box below – have fun!

Friday mystery object #319 answer

Last week I gave you this unidentified skull from the Dead Zoo to have a go at identifying:


It seems that everyone recognised this as the skull of a gull straightaway – the scars from the salt-glands on the top of the head and the shape of the bill combined to make it a bit of a give-away.

However, working out which species of gull is a bit more tricky, since many are remarkably similar in morphology, making size an important factor for consideration (I’ve talked about this before).

Now size is always a somewhat tricky thing to use for identification, for a variety of reasons. One is that there may be an overlap in size between species, another is that there will often be sexual dimorphism within a species that means you can’t just compare the length against another specimen of a species without considering sex. Then of course there’s age – if it’s not fully grown, it’s going to be smaller. Of course you also have to consider whether the bill sheath is present or absent, as this will add a few millimetres.

On top of all these issues, there’s the problem of how you actually measure the length in the first place. This is something I’ve researched in the past (link to pdf) and it’s a more significant problem than you might think. For example, when looking at the image I originally provided for the mystery object, it looks like the skull measures around 125mm, but if I chop the scale bar from the image, reduce the transparency to 50% and lay it directly over the centreline of the image of the specimen, it turns out to be around 128mm.


Length is apparently 128mm

Add to this the fact that in the original image you can see a shadow under the scale bar, it becomes clear that the scale is somewhat elevated. This is because I raise the scale to be near the vertical midline of the specimen, to help keep everything in focus and limit the effect of parallax error. Normally this is good, because it allows a more accurate estimation of the length of a 3D specimen with a longest axis near the vertical midline, but in this case the longest part of the specimen is actually at the lowest part of the skull, so the elevated scale will make it look slightly shorter than it really is (due to the parallax error I was hoping to avoid…). This means that the specimen is probably closer to 129mm or 130mm in length.

With this in mind, the discussion about the lengths of various gull skulls between Wouter van Gestle (of Skullsite fame), Ric, Tim Dixon, Richard Lawrence, Gerard van den Brink and jennifermacaire needs to be reconsidered.

Richard Lawrence reported skull lengths for a variety of gulls as follows:

6x GBBG: 129 to 141 mm
2x LBBG: 117 mm
6x HG: 111 to 117mm
9x YLG: 111 to 126 mm ( larger with beak sheath though so would be smaller without).

So factoring in a length of 129-130mm for the mystery object it seems to fit well into the range for the Great Black-backed Gull Larus marinus Linnaeus, 1758. So well done to everyone who went for GBBG – this does seem most likely to be a skull from the largest gull species.

Great Black-backed Gull by Andreas Trepte, 2010

Great Black-backed Gull by Andreas Trepte, 2010