Friday mystery object #388 answer

Last week I gave you a bit of a mean mystery object to have a go at identifying:

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I’m not surprised that very few people worked out what it is, since there’s not much to go by, and what there is, may be a little misleading.

This scrubby-looking piece of hairy skin is not from a battle-scarred Tasmanian Devil, nor is it from a rough patch on a Badger or member of the pig family and it most certainly is not from an ape of any description.

This is, in fact, from a Walrus Odobenus rosmarus (Linnaeus, 1758). This Walrus from the Dead Zoo in fact:

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People don’t think of walruses as being particularly hairy – and this one is quite definitely bald on top (I’m familiar with that feeling…). However, last week we moved this specimen and when we flipped it on its side to squeeze between some cases, we discovered a rather hairy belly (again, I know the feeling…)

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Walrus hair tends to get less dense as the animals age (insert gag here). After a century or so on open display, with members of the public who most definitely have not read the “DO NOT TOUCH” signs, and with technicians with buckets of creosote, that natural balding had a helping hand – up top.

Underneath, the hair was left untouched and in places it’s quite dense. I’m not sure if this is entirely due to people not being able to touch the specimen, or if Walrus belly hair is more dense and plentiful than on the rest of the body, to help insulate them when sitting on ice floes.

Either way, it was fascinating to be able to see a hidden part of this specimen – a nice reward for all the effort of moving it. If you want to see more of this kind of thing, check out the #DeadZooDiary!

Friday mystery object #387 answer

Last week I gave you this fuzzy critter to have a go at identifying:

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As I suspected, it proved to be tricky – small mammal taxidermy tends to be difficult, especially when it’s old, faded and a species that isn’t familar to many people. This specimen is a great example of that.

I’d love to be able to give you some clues for identification, but if I’m honest few of the distinguishing features of this species are visible (sorry!). The distinguishing features are apparently: white eye-ring (no sign thanks to fading), gray-brown fur flecked with white hairs (again it’s too faded), and a short tapering tail (just about).

This is a Dibbler or Parantechinus apicalis (Gray, 1842), which is also known as a Freckled Phascogale, Freckled Antechinus or Speckled Marsupial Mouse due to it’s flecked appearance (when it’s not faded…). Of all the comments I think Goatlips came closest with a suggestion of Antechinus, which is the genus that this species used to be included in.

These tiny marsupial carnivores feed on a surprisingly wide variety of animals, including mice, birds and lizards.

The Dibbler was declared extinct just one year after this particular specimen came to the Dead Zoo in 1883, but a couple of populations were later found in Western Australia. They’re still endangered and have a very small range, largely limited to small offshore islands where introduced predators like cats and foxes haven’t managed to spread – yet.

Friday mystery object #386 answer

Last week I gave you this taxidermy bird to have a go at identifying:

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It’s fairly obviously a duck of some sort, but there are almost 150 species in the duck family Anatidae, so that’s not really enough information.

Of course, the ornithologists were up to the challenge of working out which type of duck this was, with Wouter van Gestel dropping hints at a Steamer Duck. If you’re not familiar with Steamer Ducks, they are in the genus Tachyeres, there are only four species and they all live at the southern end of South America.

Of the four species, only one (the smallest) can fly. The others are very large, heavy and flightless. They sometimes use their small wings as a power assist in fast swimming, using a style reminiscent of an steamer ship’s paddles – hence the name.

The small wings on this specimen, as pointed out by Allen Hazen, suggest that this is one of the three flightless species, ruling out the Flying Steamer Duck T. patachonicus as a possible contender.

The three remaining species are all very similar and although some images online suggest that only one species has an orange bill, they all have quite a bright yellow-orange bill following their moult that becomes duller over time. Of course, when dealing with taxidermy you can’t fully trust things like leg or bill colour as they can rapidly fade after death and they are usually painted to give an impression of the natural colour – sometimes with a bit of artistic license.

This particular specimen is identified as Tachyeres cinereus, which is not a valid species, so I was hoping there would be someone with a useful morphological hint to help distinguish between species, but most ways of distinguishing rely on comparisons of bill length, mass and size.

However, this specimen does have a collection locality – the Falklands. There are two species of Steamer Duck that occur on the Falklands and fortunately one of them is the species that flies and has already been ruled out, so it seems likely that this is a Falkland Steamer Duck Tachyeres brachypterus (Latham, 1790).

Pair of Falkland Steamer-ducks. Image by In Vitrio, 2018

So well done to everyone who said it was a Steamer Duck – I think that’s about the best identification possible from the information provided!

On an unrelated note – over the next few weeks my mystery object answers may be a bit on the brief side. Projects at the Dead Zoo are underway that are taking up a lot of my time, so I may struggle to find time for detailed answers. If you’re interested in what I’ll be doing you’ll be able to check out the #DeadZooDiary hashtag on Twitter and Instagram, which we’ll be adding things to starting next week. Exciting things are underway!

Friday mystery object #385 answer

Last week I gave you this large-eyed specimen to have a go at identifying:

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I suspected that you’d work out the family and perhaps the genus, and I was not wrong. On Twitter there were lots of correct suggestions and Hilary was straight in on the blog comments with a nice pun, followed by various ankle related clues from jennifermacaire, Rémi, salliereynolds, Allen Hazen, katedmonson and palfreyman1414. This is indeed a tarsier in the family Tarsiidae – their name relates to the elongated tarsal bones in the foot and ankle (see arrow) which elongate the legs to help with jumping between branches in pursuit of prey:

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There are a lot of species of tarsier, many of which require genetic data to tell apart – unless you know where they’re from. That’s why I gave you this clue:

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Of course, as far as clues go it’s a bit of a mean one, since a place with this name doesn’t exist now – or ever – from what I can tell. It seems that this is a typo of “Banka Island”, which isn’t simple either since there are two Banka (or more commonly Bangka) Islands in the East Indies, separated by over 2,000 km:

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This means there are a couple of possible collection localities, which have different tarsier species present:

Rémi and katedmonson suggested that the specimen could be Cephalopachus bancanus (Horsfield, 1821). The collection locality on the label would certainly fit the species, which was first collected by Horsfield from a place called Jebus on the Sumatran Bangka Island. But does the morphology fit?

After trawling the internet for reference images and trying to assess details like the straightness of the suture between the parietal and frontal bones, the angle between the orbital ridges (and therefore the size of the orbits), the post orbital constriction and the degree of ‘pinching’ of the nasal bones, I think that they’re probably right. So well done for working out this very tricky mystery object!

Friday mystery object #385

This week I have a mystery object from the Dead Zoo that I think you’ll probably find easy to get to genus, but then I think it’ll get much more difficult:

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If it proves too hard to work out the species I have a clue that might help and I’ll add it to the post next week. Have fun!

Aaand, here’s your clue! This is where the label says it’s from. I hope that helps!

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Friday mystery object #384 answer

Last week I gave you this unusual looking skull to have a go at identifying:

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That low and elongated shape, combined with the large number of teeth and absence of a zygomatic arch – all within the context of the relatively large (but still quite small) size – all combine to narrow this down to just a few possible options.

There are a bunch of critters in what used to be called the “Insectivora“, back in the dim and distant days of my undergraduate studies. This wastebasket for things that look like they should be chasing acorns in a cartoon was rightly broken up into more meaningful cladistic groups during the great molecular taxonomic revolution in the dying days of the last century.

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Scrat, a fictional sabre-toothed squirrel that looks like every third member of the old ‘Insectivora’

To be fair, there’s a reason why the “Insectivora” lasted as long as it did and why it took molecular research to finally tease the various groups apart. They don’t have many strong distinguishing anatomical features that are seperate them into clear higher level groupings. Sure, they look a bit different at the family level, but any higher than that and they smoosh into bunch of small toothy critters, many with no cheekbones to speak of.

However, some do have a zygomatic arch, such as the talpid moles and desmans, so it’s not one of them:

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Skull of European mole Talpa europaea Linnaeus, 1758

It also lacks the large orbits of something like a Sengi or Elephant Shrew:

Skull of a North African Sengi Elephantulus rozeti (Duvernoy, 1833).

It also lacks the well-developed sagittal and nuchal crest you’d associate with the Malagasy tenrecs:

Skull of a Tail-less Tenrec Tenrec ecaudatus Lacépède, 1799.

It also lacks the backwards projecting nuchal crest of a solenodon and it’s just too big for one of the true shrews – the largest of which is the Asian House Shrew with a skull length of around 38mm.

So this specimen isn’t as hard to recognise as it could be. The very flat top to the skull with the nostrils up high is a bit of a clue – something often (although not always) associated with aquatic animals. On closer inspection there are two likely suspects – the Web-footed Tenrec or one of the Otter Shrews (which are neither otters nor shrews).

The area around the occipital is a dead give-away here. The Malagasy Web-footed Tenrec Limnogale mergulus (Major, 1896) has an occipital region that’s hard to see in a side view, because the parietals extend down quite low, whereas the Otter Shrews have much higher parietal margin that exposes the occipital region – just like we see in the mystery object.

Finally, the size is give-away. As many of you recognised and hinted at (occasionally with some dodgy puns – I’m looking at you Tony), this is a Giant Otter Shrew Potomogale velox (Du Chaillu, 1860). These semiaquatic relatives of the tenrecs are unusual in how they swim, lacking webbed feet and relying on a laterally flattened tail to swim using a fish-like undulation. So well done to Jane, Tony Irwin, katedmonson, Allen Hazen, Rémi and everyone else who managed to work out this weird mystery.

Friday mystery object #383 answer

Last week I gave you this slightly mean mystery object from the Dead Zoo to have a go at identifying:

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I say it’s mean because it’s just a small fragment from the tip of the lower jaw. It does have some pretty distinctive teeth in it, so it’s probably not the most difficult mystery object I’ve shared, but it’s also from a species in a group of animals that are quite poorly known.

That said, Chris Jarvis was the first to comment and got it right immediately. However, there was a lot of subsequent discussion about how to be sure, given the poor representation of comparative specimens available and the similarities between this species and others in the family. That family is the Ziphiidae, which are the the Beaked Whales.

These cetaceans are rarely seen due to their deep water habits, sometimes diving to depths of nearly 3km (although more usually around 1km) to feed mainly on deepwater squid that they detect using echolocation. Most of what’s known about them comes from strandings – which is where this mystery specimen comes from.

The males tend to be smaller than the females, but the males of most of the 21 Beaked Whale species have tusk-like teeth that they probably use to fight over females, although the behaviour hasn’t been recorded, only deduced from scars and the behaviour of other animals with similar sexually dimorphic characters (there’s an interesting paper on the evolution of the tusks by Dalebout et al. 2008 is you’re interested [pdf]).

The teeth occur in different parts of the jaw and have a different shape depending on the species, so the fact these are located at the tip of the lower jaw means quite a lot of the species can be discounted. If you want to be able to do the narrowing down easily I recommend an old and somewhat unwieldy to navigate, but still very useful online resource – the Marine Species Identification Portal. If you can work out the navigation you can find small line drawings of the skulls of all species in lateral view.

Once you get that far it becomes easier to search for more detailed images of the couple of species it might be, which can yield some great 3D scans to help you work it out. Both Chris Jervis and katedmonson found examples and shared the links in the comments. Here’s a nice one from the NHM, London:

This species (the Cuvier’s Beaked Whale) clearly has bigger tusks than the mystery specimen, which you can see as a scan on the excellent Phenome10K resource*. The mystery object is the distal portion of the mandible of a male True’s Beaked Whale Mesoplodon mirus True, 1913. So well done to Chris Jervis for being the first to get in with the correct identification.

It may seem a bit odd to have just this small portion in the Museum, but as far as records go they represented a managable identifiable voucher for the stranding of the species in Killadoon, Co. Mayo, Ireland back in February 1983. These days we ask for even less material to keep track of strandings – just a small skin sample will do as long as it’s collected and recorded following the guidance of the Irish Whale and Dolphin Group’s (IWDG) Strandings Network.

These samples are stored in alcohol and form the Irish Cetacean Genetic Tissue Bank which is managed in partnership between IWDG and the Dead Zoo to provide genetic data for research into whales. It’s a fantastic resource, but I doubt that anyone could identify the species represented in the samples without access to a genetics lab. And that’s why I like bones best.

*A. Goswami. 2015. Phenome10K: a free online repository for 3-D scans of biological and palaeontological specimens. http://www.phenome10k.org.

Friday mystery object #382 answer

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

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I thought it might be an interesting one, as it’s not from a species that often pops into my mind and I’m not sure I’ve ever seen one alive.

The depressions in the bone above the orbits tell us it’s a sea bird of some sort, as those are where the salt glands used to sit when it was alive. If you’re not familiar with salt glands in seabirds, I talked about them on the blog about 10 years ago (where does the time go?)

It has a very narrow and fine bill with a distinct hook at the end, which rules out the gulls and terns. Mergansers have a similar bill shape, but the rest of the skull is very different in shape and size. Cormorants and shags also have a similar bill shape, but unlike the mystery bird, their salt glands are located in their nasal region, so they don’t have the scars above the orbits.

Some of you were thrown by that cormoranty look, but a lot of you recognised this as being a small member of the petrel family. It’s a Manx Shearwater Puffinus puffinus (Brünnich, 1764) as spotted first by Hilary.

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Manx Shearwater by Matt Witt, 2010

These seabirds, with an English name taken from their breeding colonies on the Isle on Man (although they do breed elsewhere), are part of the same Order as the albatrosses. Despite being much smaller, they are also entirely marine, using their excellent sense of smell to find food over large distances over the water. This explains why you’re unlikely to see one unless you get to visit a breeding colony or happen to spend a lot of time at sea. When on land they aren’t that easy to spot either, since they nest in burrows – rather like Puffins.

Well done to everyone who worked it out, and if you got caught out by the cormorants, just remember that tip about the salt gland positon.

Friday mystery object #381 answer

Last week I gave you this specimen from the Dead Zoo’s “Unidentified” drawer:

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It’s a big and robust skull, albeit slightly battered, with no teeth and several missing pieces. However, the missing elements didn’t stop Wouter van Gestel and several others from recognising it as being from a sea lion.

That’s a really good start, but there are six living species in the sea lion subfamily (the Otariinae), which is where things get a bit more tricky, especially since they all show a large degree of sexual dimorphism to confuse things. There are also nine species of fur seals, which are close relatives and are also sexually dimorphic and hard to differentiate from sea lions.

However, there was a bit of a clue written on the specimen, for those who looked closely:

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So we know that this specimen was collected in 1855 by Dr Kinahan (an Irish geologist) from “Chinchas Is”. This group of three small islands off the coast of Peru is only really known for starting a war between Spain and several South American countries in 1864. It wasn’t actually the Islands that the fighting started over, but the large piles of guano that covered them. But I digress.

The location of the Chincha Islands immediately allows the likely species that this could be from to be narrowed down to two. Of course this is where it gets more complicated – differentiating between the South American Sea Lion and the South American Fur Seal.

However, there is a feature on this specimen which makes it really easy to distinguish from all other sea lions and fur seals, if you know to look for it. First of all, take a look at this very useful paper (pdf) by Sylvia Brunner which gives some great information on the identification of the various species.

Then, take a look at the palate of the specimen. Notice that the palate ends in a line with the point where the rear portion of the zygomatic arch meets the skull (see the red line in the image below if that doesn’t make sense):

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In every other species of fur seal and sea lion the palate ends at around the midway point of the zygomatic arch (where the writing ends on this specimen). There is just one species with such a long palate, the South American Sea Lion Otaria flavescens (Shaw, 1800) which is also referred to as O. bryonia.

It’s rare to find such a clear-cut indicative feature on a skull, so it’s always satisfying when you find one. I should note that this skull is from a female. The males are much more massive, but still share that feature of the palate.

So particular congratulations to Rémi and katedmonson who got the genus Otaria. Next time you have a sea lion skull to identify (as I’m sure you will) make sure you keep in mind that handy feature as the first thing to check and if that doesn’t help the be sure to check our Brunner’s paper.

Friday mystery object #380 answer

Last week I gave you this specimen from the “Unidentified” drawer in the collections of the Dead Zoo to try identifying:

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I don’t think anyone had much difficulty in identifying it, since it is quite a familiar and characteristic skull, but well done to everyone who worked out that this is a European Badger Meles meles (Linnaeus, 1758).

There are two other species in the same genus – the Asian Badger M. leucurus and Japanese Badger M. anakuma, so they also need consideration (skulls of all three species can be seen in this paper by Andrey Puzachenko). However, the Japanese Badger is a smaller and more delicately skulled animal and the Asian Badger can be distinguised by differences in the shape of the region around the bony bulbs that hold the ear bones (called the auditory bullae – in Asian Badgers they’re more obtuse and have a straighter lateral margin).

So apart from the distinction between two members of the same genus, this is a fairly straighforward specimen to identify, it makes me wonder why it wasn’t recognised in the collection? I think there are a couple of factors, which I’ll outline here.

The first is that the lower jaw (mandible) is missing. This is totally normal for almost any kind of animal skull you find, except these badgers, which have a well-developed bony process that locks the mandible into the long jaw articulation (known as the glenoid fossa).

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Badger skull with mandible locked in place.

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Detail of jaw articulation showing the main features. Red = mandibular articulation, Blue = inside of glenoid fossa, Green = glenoid process that helps lock the lower jaw in place.

This captive mandible is a dead give-away when you see it, but it does mean that when it’s missing it can be confusing.

A mature adult European Badger like this (as indicated by the well-developed sagittal crest) would also normally have extremely extensive wear on their molar teeth, due to the abrasive grit in the gut of their main diet of Earthworms.

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Extensively worn upper molars of an adult European Badger

But the mystery specimen has remarkably little wear on those massive molars. This suggests that it probably had a different diet than is usual for a Badger from northern Europe – and no, not mashed potatoes. The same species in southern Europe has a different diet to their northern counterparts, dominated by insects and fruit, so I wonder if the specimen was collected during someone’s holiday to somewhere in the Mediterranean?

[UPDATE 28th April 2020. Several people have kindly shared images of their badger specimens and it seems that the level of wear in my specimen is not as common as I thought. In one discussion the issue of soil type was raised and I think that may play a big factor. This specimen came from Devon, in an area with sandy soil. Other specimens from areas with muddy or silty soils showed much less wear. This may be coincidence, but it would make sense that Earthworms with coarser soil in their gut would be more abrasive to eat and therefore cause more dental wear. That would be fairly straightforward to test using museum collections. If this hypothesis about wear is correct, then the mystery specimen could be from anywhere with soils that aren’t too sandy.]

I hope you found that useful, or at least a bit of a distraction from lockdown. Stay safe!

Friday mystery object #379 answer

Last week I gave you this rather nice, but somewhat tricky mystery object to have a go at identifying:

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As well as here on Zygoma, people were checking this out on Twitter, where it was shared under the #GuessTheSkull hashtag started by @Yara_Haridy. I strongly recommend checking it out if you’re on Twitter and also giving Yara a follow as she does some great stuff.

As to this specimen, despite the difficulty, several of you managed to work it out down to species level – which I think deserves a round of applause, because this critter is not very well-known and there are few resources out there with examples of their skulls.

So, working through the options, despite having a whiff of possum about it, it can’t be a marsupial because it doesn’t have holes in the roof of the mouth (aka palatal vacuities), a shelf on the inside of the mandible or a tearduct on the outside of the orbit (aka external lacrimal duct) – all of which are marsupial traits as illustrated on this Tasmanian Devil skull below.

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The teeth are those of a carnivore (or perhaps I should say Carnivore) and the auditory bulla is single chambered, so it’s one of the caniform carnivores, rather than one of the feliforms (that long snout suggests the same). This rules out the cats, hyaenas, mongooses and the weird Malagasy carnivores like the Fossa.

From that point on it gets more difficult. Some people thought it was a bit foxy, but the lack of a well-defined post orbital process rules out any of the dogs and it’s clearly not a bear, seal or sealion. That leaves the members of the Superfamily Musteloidea, which includes mustelids, racoons, the Red Panda, and the skunks.

Quite a lot of people got busy searching through possibilities in the largest of those groups – the mustelids. However, most of this family have fairly short, broad skulls. Only the ferret badger skulls come close to this specimen and even they aren’t as narrow. Similarly, the raccoons and Red Panda’s have fairly broad and short skulls.

So that leaves the skunks and relatives in the family Mephitidae. That makes life much easier, since there are only four genera in the family and three of those have wider skulls than this. So that leaves one genus that only contains two species – Mydaus or the Stink Badgers.

That’s where it gets really hard. A few folks on Twitter and Allen Hazen on the blog comments managed to get it to genus (Allen also worked out that it’s female), but I was especially impressed by the efforts of Rémi and katedmonson who went that step further and managed to get the identification to species. Here are the features:

katedmonson said:

…Comparing the two, M.j. has the slender snout, and a larger infraorbital foramen than the M.m. The big decider for me was the tympanic bulla. They seem to match the M.j. but not the smoother M.m. Also, females in the M.j. are known to lack a sagittal crest, so my best guess is female M. javanensis. About 4 years old. That had just eaten 6 earthworms and two beetles. And she had a limp on her left hind limb. (just kidding about the 6 earthworms, it was only 3)

I’m not sure about the earthworms, beetles or limp and I personally think the age would be a little younger – maybe 2.5 to 3 years since the earthworms have a large amount of grit in their gut and that significantly increases dental wear in animals that eat them. However, I think the rest is spot on – this is indeed the skull of a female Sunda Stink Badger Mydaus javanensis (Desmarest, 1820).

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Mydaus javanensis specimen at Museum of Natural History in Vienna. By U.Name.Me, 2018

These odd looking animals have habits similar to the European Badger, foraging on the ground and in the surface of the soil for invertebrates and small prey, and sleeping in burrows during the day. However, while Badgers can be a bit whiffy, these guys have a full-on skunk-like noxious spray from their anal glands.

I hope you enjoyed that challenge, there will be another next Friday and if you want some extra mystery skulls, don’t forget to check out #GuessTheSkull onTwitter.

Have a great Easter!