Tag Archives for Mammalia

Friday mystery object #313 answer

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

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There was some lovely wordplay in the answers, with Chris getting in early with this great one:

I thought I had a shrewed idea until I saw the Bilby in the background which could show this isn’t the elephant in the room. Coot is legs be too Bandi?

This rules out elephant shrews and correctly identifies it as some kind of bandicoot, thanks to its marsupial case companion. Then palfreyman1414 dropped an anagram into the mix with:

Mere ale plus Satan?

which is so nice I wish it was correct, but alas this isn’t a Long-nosed bandicoot Perameles nasuta, although it is in the same genus.

Allen Hazen wondered “How badly does fur fade in preserved specimens?” and that turned out to be the key question, since everyone shied away from the correct identification, because one of the characteristics of this species’ pelage (that’s mammal-fan speak for ‘fur’) is that it’s supposed to have two stripes on its hindquarters or, more accurately, bars. As it turns out, fur fades quite badly in preserved specimens.

This is in fact a Marl or Western barred bandicoot Perameles bougainville Quoy & Gaimard, 1824 (NMINH:1906.301.1).

Marl

These diminutive Australian marsupial insectivores are vulnerable to introduced predators like cats and foxes, so their wild population only remains on some islands after once being widespread across Western Australia.

Even on the islands where they have some protection from placental predators, they face issues with disease, since their population has shrunk by so much it has impacted on their genetic diversity – reducing resistance to disease at the population level. In particular, a virus that causes tumour growth is affecting the animals on some islands, leaving the species increasingly under pressure.

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One island does remain free of the virus, so hopefully with proper management the Marls will be able to hang on in there.

Friday mystery object #305 answer

Last week I gave you this specimen to identify, with a clue about the tail being distinctive:

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There were lots of correct answers – the first coming from palfreyman1414 who nailed it with this great cryptic clue relating to its scientific name:

Trump assortment pack

It is indeed Potus flavus (Schreber, 1774) or as Allen Hazen and jennifermacaire hinted at with kinky clues, a Kinkajou. They’re also known as Sun Bears, Lirón (which is also the Spanish name for the Dormouse) or Micoleón (lion monkeys).

A Kinkajou at the Paradise Animal Rehabilitation Center, Volcancito, Panama. Image by Dick Culbert, 2008

A Kinkajou at the Paradise Animal Rehabilitation Center, Volcancito, Panama. Image by Dick Culbert, 2008

As the name Micoleón suggests, these South American floofsters are what happens when a carnivore tries to be a monkey. They have dexterous digits for climbing and handling the fruit that makes up the bulk of their diet and they are one of only two carnivores with a prehensile tail (the other is the Binturong) – hence that tail clue.

This tail acts like a fifth limb that helps the Kinkajou climb and in particular it allows the animal to hang down in order to reach fruit at the ends of slender branches:

Kinkajou hanging using its prehensile tail. Image by Damian Manda, 2009

Kinkajou hanging using its prehensile tail. Image by Damian Manda, 2009

Unlike monkeys, the Kinkajou is nocturnal, relying on its sense of smell and touch more than its eyesight to work out which fruit is ripe. It uses its very long tongue to scoop out fruit pulp and sometimes to feed on nectar from flowers.

All in all it’s a very curious little carnivore that looks more like a lemur than it does its closest cousin, the Coatimundis.

Friday mystery object #305

This Friday I’m giving you a game of heads or tails from the Collections Resource Centre of the Dead Zoo:

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I don’t normally add a photo of the tail, but in this case it should make the identification a doddle – literally a 50:50 shot at getting the right species. If you know what I’m talking about, then please be cryptic in your suggestions – don’t spoil it for everyone else!

If you don’t know why this tail is so significant then you should know that the skull is 10cm long and all will be revealed next Friday!

Good luck!

 

Friday mystery object #304 answer

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

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The skull of specimen LDUCZ-Z144 from the Grant Museum of Zoology

I thought that some of you would find it a bit easy, but the most diagnostic features aren’t visible in the image and it’s a nice specimen, so I went with it.

There is a bit of similarity with the skull of a ruminant, as noted by palfreyman14141, while Gerard pointed out that it’s from Africa and James M. Bryan was the first to drop a solid clue pointing to the correct species. As jennifermccaire says, it’s the very first on the list (assuming the list is alphabetical) – an Aardvark Orycteropus afer (Pallas, 1766).

An Aardvark at Detroit Zoo by MontageMan, 2008

An Aardvark (or as I prefer to call it, a Tippy-toes McSnuffleface) at Detroit Zoo. Image by MontageMan, 2008

Picking up on palfreyman1414’s observation about it looking like a ruminant, Allen Hazen asked an interesting question about the teeth, because the diet of these bizarre looking animals almost entirely consists of ants and termites, and most other mammals with a similar diet (like Pangolins and Tamanduas) have no teeth at all.

Making the presence of teeth even more weird is the fact that Aardvark stomachs have a muscular pyloric region that grinds up food in a similar way to a bird’s gizzard, so they really don’t need teeth for the major component of their diet. To top it off, the teeth of Aardvarks are utterly unlike any other mammal teeth – they’re made of tubules of dentine (giving the Order the name ‘Tubulidentata’), with no enamel, no pulp-cavity and no root – so they keep on growing:

The weird teeth of the Aardvark, made up of tiny dentine tubules.

The weird teeth of the Aardvark, made up of tiny dentine tubules.

All of this suggests that their dentition is distinctly non-standard, so it probably isn’t just a vestigial feature inherited from a toothed ancestor – which reinforces the importance of the question ‘why do they have teeth?’

Bear with me.

A 60-80kg mammal living in hot and water-scarce regions of Africa, will struggle to get enough moisture from ants and termites to survive, even if they are nocturnal and sleeping in burrows during the hottest part of the day. So how do Aardvarks do it?

Cucumbers, that’s how.

There is actually a species of cucumber that has a symbiotic relationship with Aardvarks, and it’s unimaginatively, but descriptively, called the Aardvark Cucumber Cucumis humifructus Stent, 1927.

Aardvark cucumber. Image by B. Strohbach

Aardvark cucumber (not a golf ball). Image by B. Strohbach

These weird fruits develop deep underground and have a tough skin that keeps them viable for months. Outside they’re like a leather golfball, but inside they’re watery like the cucumbers you’d put in a Hendrick’s gin and tonic – and that’s where the Aardvarks get their moisture (the Cucumber, not the G&T).

Nothing but the Aardvark has a nose sensitive enough to detect the plant, or claws powerful enough to dig into the hard-baked earth to access the fruits (or possibly only an animal that mostly eats ants is desperate enough for some culinary excitement to go to all that effort for something that the rest of nature views as a lacklustre garnish). The Cucumber’s seeds need to pass through an Aardvark to become viable and those seeds get distributed underground with a healthy dollop of fertiliser in what is otherwise a harsh environment.

The leathery skin of the Cucumber is almost certainly the reason why Aardvarks are alone in having teeth amongst the termite and ant-eating mammals. It also explains why those teeth grow constantly – and why they get so worn down.

I think that’s pretty awesome.

Now you may be wondering if I’m making all this up, but honestly, the world really is that weird (and wonderful) when you look at it closely enough!

Friday mystery object #300 answer

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

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When it arrived on my desk in an decorative box, with bundles of bone wrapped in blue tissue and tied with gold ribbon, it had a small label saying:

Skeleton of Mongoose, Africa.

Now, I know that having the continent would have been of help for the identification, but I didn’t want my 300th challenge to be too easy.

So how was that initial identification of Mongoose? It was certainly up there in the first of the comments, with Ric Morris (expert on British mammal bones, whose book I am eagerly awaiting) providing a beautifully crafted suggestion. Unfortunately it isn’t right, as the mongooses mongeese Herpestidae* tend to have a better developed post-orbital process (that’s the pointy bit on top of the skull, behind where the eye would be) and a corresponding process on the zygomatic (that’s the cheekbone), with the two sometimes meeting to form a post-orbital bar. They also tend to have more robust teeth.

Another (very) cryptic clue came from jennifermacaire who suggested that it was a civet (which can either be a type of viverrid carnivore or a French game stew). This suggestion was supported by henstridgesj and it’s closer than the mongoose suggestion, as the specimen is indeed from a species in the Viverridae. This was noticed by herpderpatologist who provided a handy tip for spotting the difference between mustelids and viverrids:

The split auditory bulla is a clue! It’s something I associate with viverridae;…

If we know that this is a viverrid, it narrows it down to one of  just 38 species…  which is still quite a lot. But by trawling through the images of viverrid specimens on the University of Michigan Animal Diversity Web it becomes easier to start narrowing down the likely group within the Family.

In this case it led me to the genets.

There are quite a few genets, with the Subfamily Genettinae containing in the region of 16 species. Distinguishing between them isn’t entirely simple, as they all look pretty much alike, but there is an excellent French resource that has detailed anatomical characters and images of specimens to help distinguish between genet species.

Working through this I found that the two best options were the Common Genet and the Cape Genet and distinguishing between them is not simple. I’m leaning toward the Cape Genet (or Large-spotted Genet) Genetta tigrina (Schreber, 1776), based on the spacing between the tympanic bullae (the bulbous bones under the skull that house the ear bones), the reduced lingual cusp on the P3 (that’s the tiny bit that sticks out towards where the tongue would be on the upper third premolar) the form of the upper first premolar (P1) and the shape of the maxillary-palatine suture (that’s the junction between the bone of the palate and the part of the upper jaw that supports all the teeth except the incisors).

That’s quite a lot to take in, but by getting your eye in and scanning through images it’s surprising how quickly you can narrow down options by rejecting images where you can see clear differences in the tympanic bulla configuration or cusp pattern on the P3 to leave a couple that need more careful consideration.

And just for the sheer squee of it, here’s what a Genet looks like when it’s alive:

Common Genet, by Peter 2011

Common Genet, by Peter 2011

I hope you enjoyed the challenge of the 300th mystery object!

 

*N.B. the plural of mongoose is “mongooses”.

Friday mystery object #299 answer

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

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I thought the presence of fur would make it easier than usual, but of course, hair hides a lot of rather useful diagnostic features that you can find more easily in the bare bones.

However, you managed to pick up on a couple of the key features that gave this specimen its name: it looks like a lagomorph (one of the hares, rabbits or pikas) or maybe a larger rodent and it looks like a macropod (one of the kangaroos, wallaroos or wallabies). Several people wondered about it being a Kangaroo-rat, but that distinctive back foot, with its big central toe and then the skinny little side toes (you have to look carefully), tells us that it’s the other way round and this is a marsupial that looks like one of the placental glires (that’s the group containing the rodents and the lagomorphs).

The marsupial identification was initially spotted by palfreyman1414 and tenaciously defended by Rebecca, who was on the right track when she veered toward it being something in the Potoroidae (the rat-kangaroos, potoroos and bettongs), a suggestion that was put forward in a more cryptic way by jennifermacaire.

This is in fact a Rufous Hare-wallaby or Mala Lagorchestes hirsutus Gould, 1844, which marsupial wrangler Jack Ashby spotted with ease:

I should say that it is indeed VERY faded, after spending over 100 years in a glass ceilinged gallery.

These small macropods live on a few islands in Western Australia, but their original wider range has been dramatically reduced by changing land use patterns resulting from the breakdown of the relationship between the Aboriginal people and the land, caused by encroachment and systematic persecution by European settlers. It’s not onlyhumans who suffer when people treat each other badly.