World Rhino Day 2013

I thought I’d do a quick update on rhinos here on Zygoma, since the theft of their horns from museum collections is something that I’ve been keeping an eye on for a while.

For the museum professionals out there it has been tough, with more thefts taking place since I published on the situation from a museum perspective at the end of 2011. On a more heartening note, there have been more arrests as well.

Of course, things have been far tougher on the rhino populations.

Poaching rates in South Africa show a steep increase since 2009, when the new wave in poaching was started after a rumour that a Vietnamese official was cured of liver cancer using powdered horn. It will be interesting to see whether the increase in poaching rate will follow the trend of the last few years, following the recent arrest of a man reputed to be one of the kingpins of the poaching and smuggling operation from South Africa.

rhino_poaching_prediction

Since the boom in poaching, rhino populations have been in decline around the world. In some cases that decline has been very rapid. In 2011 the Western Black Rhinoceros (Diceros bicornis longipes Zukowsky, 1949) was declared extinct and the Javan Rhinoceros (Rhinoceros sondaicus Desmarest, 1822) now only has one surviving subspecies, made up of maybe 40 individuals. All of this because of a single story about cancer.

As with most anecdotal claims for cancer cures (from use of vitamins to homoeopathy) there is no good evidence that rhino horn has any effect. Spontaneous remission happens and, assuming the story about the Vietnamese official contained any shred of truth there were probably numerous other treatments being used at the same time, making it impossible to identify which treatment had any effect.

If rhino horn was effective, then you might expect the countries that use it, like China, to have a lower cancer mortality rate than other parts of the world – but this is not the case. Even practitioners of Traditional Asian Medicine have explicitly stated that there is no evidence that rhino horn can cure cancer.

Moreover, if rhino horn did have any effect on a cancer, that effect should also be found by using powdered cattle hooves – a cheaper and more sustainable product. Rhino horn use is not sustainable at all. If the poaching rates continue to increase as they have been, my very quick and dirty calculations suggest that rhinos could be extinct in South Africa in as little as 10 years.

predicted_SA_rhino_decline

This is why it’s so important to raise awareness of the problems facing rhinos and communicate the fact that rhino horn is not a cure for cancer. Time is potentially very short for the populations that remain.

Friday mystery object #205 answer

Last Friday I gave you these tiny bones to identify:

mystery205

Several suggestions were put forward with soph coming close with the suggestion of a broken furcula and Lena and henstridgesj correctly suggesting the clavicles (or collarbones) of a Cat Felis catus Linnaeus, 1758.

Cat clavicles, like the clavicles of a variety of other animals, are much reduced and are no longer connected to the scapulae (shoulder blades). This allows the scapulae to move much more freely during running, which can increase stride length and in the case of Cats it allows the animal to fit through holes big enough to get their heads through (assuming the Cat isn’t a bit too portly).

These sorts of vestigial structures are interesting from an evolutionary perspective, since they serve little or no direct function, but they still develop as a result of inheritance from ancestral forms that did use them.

In the case of Cats that form would have been around quite some time ago (probably 61.5 – 71.2 million years ago) since the closest related group to the Carnivora with a well-developed clavicle (that I can think of) would be the Chiroptera (bats), where it plays an important role in flight.

Since that divergence of the Chiroptera and the lineage giving rise to the Pangolins, Carnivora and Ungulata the clavicle has been pretty much completely lost, so it’s interesting that even a vestigial form occurs in Cats.

It’s funny to think how such small bones can raise questions that lead us through millions of years of evolution in search of answers, but that’s the nature of studying nature!

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 #203 answer

Last Friday I gave you this rather large scapula that I discovered in a crate in the Horniman’s stores to identify:

mystery203

It wasn’t an easy one, since there are relatively few distinctive features on a scapula compared to something like a skull.

Jake has talked about scapulae on his blog before and that provides a good place to see that this specimen is most likely from an ungulate – but an ungulate much bigger than a Red Deer. This led to suggestions for Cow, Horse, Aurochs and one of the larger species of deer. 

Outside the comments section on Zygoma there were also suggestions of Giraffe and Giant Irish Deer and I wondered about Camel.

All in all, there were a lot of suggestions, but none of these looked quite right when I searched for comparative material – although finding good images of scapulae online wasn’t easy. I did, however, find a useful video explaining the differences between Horse, Cow (or Ox) and Camel scapulae:

This was enough for me to rule out each of those animals, although the closest was the Cow – in particular the relative sizes of the two faces (called fossae) on either side of the raised ridge called the spine. However, the shape of the acromion (the hooked bit of the raised spine that points towards the shoulder joint) didn’t seem blunt enough for a Cow.

The size differences in the fossae turn out to be about the same in Sheep and deer as in Cow, which led me back in the direction of Jake’s deer scapulae, which seemed to most closely match the shape, if not the absolute size.

Taking the size into account I realised that this animal must stand almost twice the height of a Red Deer, which narrows it down to just one modern species – the Moose or Eurasian Elk Alces alces (Linnaeus, 1758), which can stand at over 2m at the shoulder compared to the Scottish Red Deer’s (still imposing) 1.22m.

Bull Chukotka Moose by Beloki

I still need to double-check my identification against a confirmed Moose scapula, but from looking at some images of Moose skeletons online it seems that the shape of both the fossae and the acromion fit well.

So a big thanks to everyone for their help in identifying this and special props to newcomer Jeanie who seems to have been spot-on about this being from a cervid. Thanks!

Friday mystery object #201 answer

Last Friday I gave you this object to have a go at identifying:

mystery201

It was not an easy one and I was hoping that nobody would work out what it was, but as usual some of you managed to figure it out. So, big congratulations to cackhandedkate and Jake who suggested the surface of a tongue and henstridgesj for working out that these 2mm hooks are from the tongue of a cat – a BIG cat.

These are in fact the barbs or aculei  from the tongue of a young Tiger Panthera tigris (Linnaeus, 1758)

aculei_tiger_tongue

This small sealed box has no date associated, but the style of the label and the number suggest that it probably one of the early specimens acquired by Frederick Horniman before he built the Horniman Museum, dating to 1886 or perhaps earlier.

The aculei on cat tongues are interesting adaptations not seen in other carnivores (at least none that I can find any information for). The rows of hooks are ideal for grooming – like a stiff brush, but they are also a useful tool for removing meat from bones.

This is particularly handy when you have a relatively short face with incisors that form a broad straight row for clamping windpipes shut, unlike the narrower incisor row that you find in the dogs, which act a bit like like tweezers for removing meat on bone.

Photo of Tiger grooming by Tennessee Wanderer on Flickr

Photo of Tiger grooming by Tennessee Wanderer on Flickr

The aculei are made of keratin, the same protein that claws, hair and horns are made from. It may seem quite difficult to evolve lots of small claws on your tongue, but you might be surprised to know that the cells that secrete keratin (called keratinocytes) are the the most common cells on the surface of your skin (including your tongue) where they play an important role in fighting infection and repairing damage.

In order for these cells to secrete enough keratin to grow a small claw, they need to get a bit bigger so they can secrete more of the protein. They also need a simple mechanism that gives the resulting structure a useful shape.

Mammalian tongues are already covered in little structures called ‘papilla’, with three types containing taste buds and one type, the filiform papilla, that provide grip on the surface of the tongue, making it easier to eat ice-cream. It’s these filiform papilla that have adapted in the cats to make a structure with enough grip to lick the meat off a bone.

I’m actually a bit surprised that more mammals don’t have tongue barbs like cats, although there are other animals out there that have specialised tongues with other keratinous structures, like the horny tips of Woodpecker tongues and the tiny bristles of some Fruitbats.

Still, nothing says ‘obligate carnivore’ like a tongue covered in sharp hooks. Considering the length of the aculei I wouldn’t fancy being licked by a Tiger – their tongue looks like it could take human skin right off. However, it has given me an idea for how to quickly and easily remove wallpaper using a Tiger and a bucket or two of Bovril.

Friday mystery object #201

This week I have a mystery object that’s a bit dusty and not much to look at, but which is one of my favourite historic specimens at the Horniman Museum.

I have the feeling that it might stump everyone this time, but let’s see how you do. Any idea what this is?

mystery201

Scale = 10mm

As usual you can put your comments, questions and suggestions below and I’ll give you some clues if you need them. Good luck!