Friday mystery object #371 answer(ish)

Last week I gave you these two genuine mystery specimens from Katharine Edmonson to get your thoughts on:

Tooth-1_9464

IMG_9315

It was most definitely NOT an easy challenge, and I’m still not sure I know the answer to either, even after looking at every species I can think of that might have similar structures.

These are both clearly teeth, considering the internal details:

One image shows the root area of a full tooth, and one shows a section through a tooth – both of which provide really useful information. For example, the full tooth has a central dentine growth that you often find in animals that deal with a lot of strain on the tooth or where infection has got in (I’ve shown this before in elephant ivory).

The sectioned tooth shows a zone of dentine in the middle that suggests some hard use. Notably, that zone matches the shape of the cross section, so those grooves in the sides of the tooth aren’t from wear – they must be intrinsic to the tooth shape.

Generally, tusk cross sectional shape reflects the shape of the socket (until it gets worn down) – so that gives a pretty good way of narrowing down possible options. For example, I’d discount walrus, since they have an almost rectangular section. Warthog tusks have a section somewhere between the number 8 and a mushroom in shape, and Hippopotamuses have a triangular section to their canines, but their incisors are quite circular in section.

Warthog tusk socket

Warthog tusk socket

Then there are wear facets, that can give teeth and tusks a characteristic shape. Hippo canines grow in a corkscrew if unworn, but by rubbing against each other they remain sharp and fresh (like rodent teeth).

This means that teeth and tusks can look weird if the normal wear is disrupted, either by not happening or by happening too much.

There are also unexpected tusks that need to be considered, like the Indian Rhinoceros or dugongs that have hidden tusks.

Of course, some animals have really weird tusks, especially when they’re young or if they’ve experience something that leaves the tusks deformed or altered – which can make identification really hard.

There were a lot of suggestions of Sperm Whale tooth, which is a possibility, but I’ve not seen any that really come close. It may be that both of these are tusks from something more unusual, like beaked whales, but I have looked at a lot of examples of beaked whale teeth and I can’t find any examples that match either of these.

On balance, I think that the first of the tusks may be a Hippopotamus incisor that’s been misaligned with another tooth, causing excessive wear and horizontal stress lines to appear during tooth growth – this is rampant speculation I hasten to add. The second looks a lot more like a Warthog tusk in section than anything else, although the end is more spade-like than I’d expect.

So, after a lot of consideration I’m still uncertain of the identification of either of these, and I would be delighted to hear if you have any more thoughts!

Friday mystery object #371

This week I have a couple of guest mystery objects for you to have a go at identifying. Here’s the first:

Tooth-1_9464Tooth-3_9467Tooth-4_9467

And this is the second mystery object:

IMG_9315IMG_9314IMG_9316

These photos are from Katharine Edmonson and they’re real mysteries, so no need for cryptic clues or hints – let’s see if we can work out what these are using our collective knowledge. Should be fun!

Friday mystery object #301 answer

Last week I gave you this mystery tooth to have a go at identifying:

mystery301bmystery301a

There were a variety of answers, but the first few took this as a worn canine tooth, presumably due to the respectable size and robustness. However, consensus shifted to this being an incisor, meaning it would have to be from a large animal – which is spot on. Moreover, it’s a large animal that was once resident in Ireland.

After that there were a variety of ideas brought up, from all manner of beasts including Sheep, Badger (or perhaps Pine Marten since a cryptic M.m. from the Irish fauna could be either Meles meles or Martes martes), Cave Bear, Coyote, Wolf and even Human. There was one just correct identification however, by Tony Morgan who recognised it as a Hyaena incisor.

It is in fact the lower left third incisor (or i3) of Crocuta crocuta (Erxleben, 1777) – the tooth you can see in this (very gnarly) Hyaena mandible, although it’s much less worn:

Hyena mandible

Hyaenas have an incredibly thick enamel layer on their teeth which creates a distinct neck on the incisor where it stops, which is further defined by the root of the tooth bulging laterally below – presumably to help deal with the forces of prey capture and perhaps the Hyaena’s impressive bite strength.

mystery70

The robust skull of a specialist bone-crusher

You probably don’t think of Hyaenas as being native to Ireland, but until 39,000 or so years ago they ranged right across Eurasia, including those parts of Europe which were to be cut off by changing sea levels to form Ireland and Britain.

It’s strange to imagine a species normally associated with the African savanna strolling around the Emerald Isle, but it’s worth remembering that the world is a constantly changing place and wildlife moves around to cope as the environment alters. Borders and boundaries are very human concepts and other species only pay attention when you have a genuine barrier, like an ocean, a mountain range or (if you’re a Dormouse) a break in the tree canopy.

That’s one of the problems with current climate change compared to past climate variations. The speed of change is so great that some species don’t have time to move into new habitats and there are fewer suitable habitats available, because humans have cleared them for farming or building. Meanwhile, some other species can find suitable habitats and are able to move – but they will then often be considered an invasive pest. Now  the chances of Hyaenas returning to Ireland are pretty slim, but if they did I expect most people wouldn’t be too pleased, although you never know…

Kevin Richardson kisses hyena. Image by Kevin Richardson, 2007

Kevin Richardson kisses hyena. Image by Kevin Richardson, 2007

Friday mystery object #279 answer

Last week I gave you this mystery object to identify:

mystery279

It’s the kind of thing you find in museum collections quite often, but it will commonly be misidentified – especially in anthropology collections where (in my experience) it will commonly be referred to as a claw or big cat tooth.

However, nobody who commented went down that route, recognising that the hollow base and well defined crown indicates that it’s an open rooted tooth of some sort. In mammals an open root at this size that would suggest a pig tusk or perhaps a whale tooth, but this isn’t mammalian.

In fact, this tooth is from something even less cuddly than a whale, something crocodilian. This was recognised first by Carlos Grau, but others who came to the same conclusion included Jonathan Larwood, Daniel Jones, palfreyman1414, Wouter van Gestel and Charne. More specifically, this tooth is from a Gharial, Gavialis gangeticus (Gmelin, 1789). This Gharial from the Grant Museum of Zoology in fact:

mystery279_Gharial

Grant Museum of Zoology Specimen LDUCZ-Y215

Gharial teeth are a bit less conical than the teeth of most crocodiles and alligators. Presumably the curve helps prevent their main diet of fish from getting free when caught.

Gharials are sexually dimorphic, with the adult males bearing a big rounded bony  knob on the end of their rostrum, this is where the name Gharial comes from, as this feature resembles a local earthenware pot called a “ghara”. Sadly, these distinctive crocodilians are critically endangered, with just a few hundred left alive in the wild. They are affected by habitat loss, egg theft and use in traditional medicines.

More mysteries next week and if you fancy hearing me talking about animals you might be interested in coming to Animal Showoff at the Grant Museum of Zoology next Thursday evening!

Friday mystery object #204 answer

Last Friday I gave you this unusual tooth to identify:

mystery204

It had me a bit stumped, as I couldn’t think of many things big enough for a tooth this size and I could think of even fewer with a tooth this shape.

My first thought was one of the smaller toothed whales, since this would be in the right size range and the open root is similar to what you see in a Sperm Whale:

Tooth of a Sperm Whale in a Hand by Lord Mountbatten

But the low and wide shape was all wrong for most of the whale teeth I can think of, except perhaps for the rather odd tusks found in the mandibles of some species of beaked whale.

In fact, I was thinking that it might be the tusk of a juvenile or female Gray’s Beaked Whale, given the shape of the male’s tusks.

However, Laura McCoy made a very useful observation (initially via ermineofthenorth) about the upper incisors (or premaxillary incisors) of the  Continue reading

Friday mystery object #204

This Friday I have something for you to identify that has been puzzling me for a while. It looks very distinctive, but I can’t narrow down what it is, so I’d really appreciate your thoughts.

Can you work out what this is?

click for bigger image

As usual you can put your suggestions and thoughts below and I’ll do my best to reply. Feel free to ask questions, but at the moment I can only provide answers based on the physical object because I have no idea where it came from or when we got it. It’s a real puzzle!