Friday mystery object #310 answer

Last week I thought it was time for some more bones, so I gave you this specimen from the Dead Zoo to have a go at identifying:

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There was no scale, the photo is far from ideal and the specimen isn’t in the best condition, but the animal is pretty distinctive, so I thought it wouldn’t prove too much of a challenge – and it turns out that I was right.

Palfreyman1414 was the first to identify it to genus level, correctly recognising that it was one of the two Notoryctes species of Marsupial Mole from Australia.

The weird limbs are a pretty good indicator this being a digger, with large muscle attachments and robust forelimbs, but it has couple of large claws rather than the ridiculous giant hands of the Old World Moles and it has a shorter skull.

Double prep mole from the Horniman Museum

Double prep of an Old World Mole Talpa europaea from the Horniman Museum & Gardens

The skull is more similar to that of the golden moles of southern Africa, although their rostrum (nosey bits) tends to be more concave while the marsupial moles have a more convex rostrum (and in some cases, weirdly flaring zygomatic arches).

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Lateral view of the skull of a Giant Golden Mole Chrysospalax trevelyani from the Grant Museum of Zoology

Now distinguishing between the two species of Marsupial Mole is a bit more tricky, not least because they are quite poorly known animals and there aren’t many specimens available for comparison – this is particularly true of the Northern species, which was first described as recently as 1920.

This is actually quite useful to know, since the mystery specimen came into the collection in 1897 – from Southern Australia – so it’s safe to say it’s the Southern Marsupial Mole Notoryctes typhlops (Stirling, 1889), but that’s not very helpful from a morphological perspective.

So far I’ve not found any useful skeletal features that help differentiate the two species, but apparently their fur colour is a little different, with the Northern species having pinkish or cinnamon fur and the Southern species having yellowish-white to a deep gold. To see what they look like with their fur, here’s the taxidermy partner to the mystery skeleton:

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Taxidermy Southern Marsupial Mole Notoryctes typhlops in the National Museum of Ireland – Natural History

As with most moles these subterranean critters have adapted to spending much of their time underground by losing their eyes, investing in some serious digging equipment and tuning in to smells and low frequency sounds.

I hope you enjoyed this little tour around the main moles of the world! More mysteries next week.

Friday mystery object #309 answer

There are lies, damn lies and statistics* and then there are inaccurate statements made from assumptions that are based on insufficient knowledge and poor research. Last week I fell into this sort of untruth when I offered up this diminutive mystery object that I said was from Ireland:

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My excuse for that untruth is the fact that the specimen was in a part of the collection dealing with native species (which I forgot also includes British taxa, because the collection is old enough to have been split into “native” and “foreign” before Ireland stopped being part of the UK) and I’d quickly checked the distribution with reference to a handy online checklist of British and Irish Hymenoptera, but I then missed the bit under the species that said the range was restricted to England. I assumed based on context and as a result I got it wrong – and we all know that we should never ASSUME, because when you ASSUME, you make an ASS of U and ME*.

So thanks to jennifermacaire  and David Notton for pointing out my mistake – it is much appreciated. I should have checked the label for the collection locality, but unfortunately the image was taken as a snap on my phone while bagging the drawer containing this specimen (while I was preparing hundreds of of other such drawers and insect boxes as part of a major collections move) so I didn’t get the chance. This is actually a bit of a problem for digitisation when insects are pinned like this, because the label is invisible from above.

insect room

Insect boxes bagged for transport and freezing

If I was more familiar with the insect fauna of Britain and Ireland it would have helped, but as you may be aware, my main area of experience is in bones and the critters that have them, so my knowledge of insects tends to be quite generalised or restricted to particularly important or interesting species that I’ve had reason to research.

Skull of female Jaguar in the Dublin Dead Zoo

The kind of specimen I really understand

This is one of the challenges in my role as curator of Zoology and Entomology at the National Museum of Ireland, where I work with somewhere in the region of 2 million specimens, covering the whole of the animal Kingdom, from all over the world.

Normally museums with collections of this size would have a few specialist curators to focus on the main taxonomic divisions, but for the time being I’m dealing with the lot, so I have a steep learning curve to get up to speed with the whole collection. Of course, it’s well worth it, as there are some incredible specimens in there – either because of what they are, or who they were collected by and how important they are for science and culture.

Wasps collected by Charles Darwin during the Voyage of the Beagle.

Wasps collected by Charles Darwin during the Voyage of the Beagle.

Anyway, excuses aside, I expect you’re keen to find out what that small hymenopteran was. Chris very quickly identified it as one of the small, solitary carpenter bees. This is the only one that is “native” – in that it occurs in Southeast England – and even then it’s pretty rare to find it except in downlands in the South, mainly in East Hampshire.

The name is Ceratina cyanea (Kirby, 1802) and the female excavates a burrow in the stem of a dead plant, making tiny cells with walls of sawdust in which she lays eggs – hence the name “carpenter bees” for the group that shows this behaviour.

Another mystery object to come next week – this time it will hopefully be a bit less misleading!

 

*Attributed to Benjamin Disraeli, by Mark Twain

*I’m attributing that to the fictional character Dawn Summers from Buffy the Vampire Slayer because that’s where I heard it first, but it was coined by Jerry Belson

Friday mystery object #302 answer

Last week I gave you this egg to try your hand at identifying:

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Eggs can be tricky, since they are largely similar in shape and, since egg collecting was banned many years ago, there are few modern resources for identification.

However, you can pick up clues by thinking about colour and pattern and working out what advantage it may have. So you might expect a brightly coloured egg to be laid in a well disguised and deep nest, where it’s unlikely to be spotted except by the parent, whereas a yellowy speckled egg is more likely to be camouflaged if laid in a fairly open, sandy environment.

So this egg was probably laid somewhere near the sea, which means it’s probably from a charadriiform bird (those are the shorebirds).

Now there are a lot of shorebirds, but this egg is pretty big and it lacks the strongly conical shape you’d expect from a cliff-nester like a Guillemot (the shape means it rolls in tight circle, making it less likely to be blown or knocked off a cliff). That actually narrows it down to a handful of birds that makes comparison easier. Curlew eggs, for example, are a similar size, but they tend to be more grey and have larger blotches, plus they’re a bit less elongated.

This particular egg has the shape and colour of a gull egg and large size means it’s almost certainly the egg of a Greater Black-backed Gull Larus marinus Linnaeus, 1758.

I would say more, but at the moment I’m at the natural history highlight of the year – the NatSCA conference. Here’s the Twitter feed in case you’re interested in the discussion:

Friday mystery object #291 answer

Last week I gave you this skull from the Grant Museum of Zoology to identify:

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I thought this would be a fairly easy one and so I wasn’t surprised when Chris was straight in with a correct identification, in a suitably cryptic manner of course.

The huge open sinuses inside the orbit and openings around the auditory bullae (as spotted by palfreyman1414) immediately suggest that this is an animal that dives deep underwater, as the large openings help prevent pressure from building up inside the skull. The shape of the teeth are another giveaway that this is a fish-catching mammal in the Order Carnivora. It is of course a seal.

But what kind of seal? There are 33 species of pinniped, so there are a few options, although the large and distinctive species like Walruses can be ruled out for obvious reasons. In this size range and with multicusped teeth like these we’re looking at one of the true seals (the Phocidae) at the medium to small end of the size range.

When you start looking at the skulls of seals in this range, you need to look  closely. It lacks the flat top of the head and steeply sloping profiles following the nares of a Grey Seal, plus the interorbital distance (the distance between the eyes) is much smaller.

It lacks the inflated nasal region of the cold water Bearded Seal, Ribbon Seal, Ringed Seal and Harp Seal, which need well developed nasal turbinates to help warm the air they breathe in. It also lacks the deflection of the zygomatic below the orbit that is seen in the smaller species like the Caspian and Baikal Seals.

Overall the morphology is most similar to either the Spotted Seal or Harbour Seal, but picking between the two is tricky, especially since the Harbour Seal has around five subspecies that vary somewhat in size and shape of things like the auditory bullae. There is a list of characters that can be used to distinguish between the skulls of the two species by John J. Burns in the Encyclopedia of Marine Mammals. Using that as a guide I think this is a Harbour Seal Phoca vitulina Linnaeus, 1758.

Thanks to everyone who had a go at identifying this – I hope you had fun with it!

Friday mystery object #286 answer

Last week I gave you this mystery object to identify, found on a beach in Ireland:

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It led to a lot of great cryptic comments relating to marine birds and sternum keels, but Lena was the first to comment and was spot on with the species (or at least as far as I can tell!)

Bird sterna are quite distinctive, with overall shape giving an indicator of mode of life. Long narrow but well-developed keels like this tend to be seen in marine birds that use their wings to fly underwater. The shape of the bottom and sides of the sternum tend to be quite specific to particular genera and species, making sterna pretty good for identification.

Of course that depends on having good comparative material and I was delighted to find John Rochester’s very helpful Flickr page, that has a comparison of British Auks (in this case we’re talking about the geographical British Isles rather than the sociopolitical concept of Britain).

If you take a look at those images you’ll notice that one fits the shape very well indeed – the Guillemot or Common Murre Uria aalge (Pontoppidan, 1763).

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Guillemot with its meat and feathers on. Image by Dick Daniels, 2011

So that’s the identification I gave to Emer, Ronan, Rory and Paddy who found it on their hols!

 

Friday mystery object #283 answer

Last week I gave you this zoomed in picture of a specimen to have a go at identifying:

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It was a bit tricky, so I also gave you this bonus clue to help:

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I was impressed to see that, despite the limited information available from the images provided, many of you managed to work out that this shows the lightweight ‘honeycomb’ structure that supports the casque of a hornbill.

That was the first challenge but, as ever, I was keen to see if you could get the identification to species – far more of a challenge considering the lack of a side view of the skull and lack of a scale. To make up for that I’ve decided to provide the necessary image here:

Ceratogymna atrata skull

I won’t say what species this is in this post, as I normally would, just to give some more of you a chance to make the identification yourself. However, what I will say is that the very first response by Wood contained a link to an image of the correct species and later to a blogpost featuring this very specimen. In that post there is a discussion about the appearance of the casque, with speculation about whether it had been damaged during preparation, resulting in its appearance. However, as Richard Lawrence pointed out, this appearance is actually normal for the skulls of several species of hornbill.

I will also say that the discussion between Daniel Calleri & Dan Jones and Richard Lawrence about whether it was a hornbill from a genus starting with A or B was interesting and I initially thought it was an A, but am now convinced that it’s a C.

If you’re desperate to know which species it’s from, here’s a link to the skullsite.com page about it.

 

Friday mystery object #279 answer

Last week I gave you this mystery object to identify:

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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:

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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!