Friday mystery object #364 answer

Last week I gave you this fantastic skull from the Dead Zoo to have a go at identifying:

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It’s clearly a bird and it has a distinctive shield of keratin at the base of the bill that helps with the identification. There aren’t many birds with shields like this, although there are plenty with casques, wattles, combs and crests that need to be ruled out when thinking about possibilities.

The group that springs to my mind when it comes to facial shields like this are the Jacanas or Jesus birds, named for their apparent ability to walk on water which Wouter alluded to in the comments. Of course, they don’t actually support themselves on the surface of the water (unlike the Common Basilisk), rather they walk on vegetation at the water surface, spreading their weight across ridiculously long toes.

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Lesser Jacana, by Derek Keats, 2016

Not all Jacanas have facial shields, but there are a few that do, including the Northern Jacana Jacana spinosa (Linnaeus, 1758) that lives in South America – which is the species that this mystery skull belongs to.

The Wattled Jacana can be ruled out because it has additional drooping lobes on the lower part of the shield. There is also a Crested Jacana that looks similar to this, but the shield runs along the skull more, rather than across the front of it.

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Northern Jacana, by Benjamin Keen, 2012

The Northern Jacana also has yellow spurs on its wings that it uses for defence, which is quite distinctive. Here’s the skull back on its skeleton – you might just be able to make out those bony spurs on the wing.

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You may notice that the scientific name on this specimen label is very different to the scientific name I used – yet another example of some old taxonomy that will need updating in the collection. Some jobs are unending in museums!

Friday mystery object #363 answer

Last week I gave you this crusty critter to identify:

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It’s not the easiest mystery object, since there are around 850 species of crab, and several converge on similar forms. However, the triangular body and spindly legs meant that everyone recognised this as a species of spider crab in the Superfamily Majoidea.

Beyond that it gets harder, although there are resources out there to help. The Marine Species Identification Portal has a useful key for species that occur in the North Sea. I know that’s not always useful in these instances, but as it turns out, this particular species has a range across the East Atlantic and into the Mediterranean, including populations in the North Sea.

This little crab is Pisa armata (Latreille, 1803), which is one of several spider crabs that camouflage themselves with sessile animals and algae from their local environment, earning them the name Decorator Crabs.

Decorator crab covered in stinging hydroid polyps, which defend the crab while benefiting from food scraps and greater mobility. Image by Nick Hobgood, 2006

Decorator crab covered in stinging hydroid polyps, which defend the crab while benefiting from food scraps and greater mobility. Image by Nick Hobgood, 2006

Bit of an obscure one for you, but Diane Barlee did figure it out on Twitter, so it was manageable. Watch out for more mysteries next week!

Friday mystery object #359 answer

Last week I gave you this fishy mystery to have a go at solving:

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I find fish a bit tricky, simply because there are so many different species out there – 33,100 described so far and rising. That’s more than all other vertebrates combined, so it’s not surprising that they can be a challenge.

However, this cartoonish looking little fish has some quite distinctive features that help narrow down the identification. There’s the duck-face with a couple of little barbels between its eyes and the clumping of the fins to the tail end. It also has a nice colour, but as I regularly say, that’s seldom a very reliable guide.

Generally, fish shaped like this don’t swim fast, they don’t lie flat on the sea bed and they don’t wriggle through weeds. This is the shape of a clinging fish – the kind that hold fast to a surface and let the world wash over them.

There are a good fish that do this, but I did say that this one is from Ireland, which helps narrow it down even more – enough for Chris to identify it correctly. This is a Cornish Sucker Lepadogaster purpurea (Bonnaterre, 1788). These weird little fish are pretty awesome. They cling to rocks along the shore with a suction cup made from their fused pelvic fins and they can change colour to blend into the rocks they attach to. Partly this will be for camouflage to avoid predators, but it will also be to help them ambush the smaller fish and crustaceans that they feed on.

One small issue for me is that the name on the label for this specimen is Lepadogaster lepadogaster (Bonnaterre, 1788). The taxonomy of this genus was reassessed in 2002 and the northern population of Lepadogaster (including those from the UK and Ireland) was found to be distinct from the more southerly distributed population. So once again, I need to update a label because advances in taxonomy have messed up our 100+ year old information. That’s the trouble with science – it keeps finding out new stuff.

 Friday mystery object #357 answer

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

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Despite it having a passing resemblance to a Xenomorph Facehugger, it’s a real animal from planet Earth, although not from earthy bit. As many of you recognised, this is one of the pycnogonids or sea spiders.

This group of arthropods is placed in the Chelicerata along with spiders and horseshoe crabs on the basis of their morphology, although genetics suggest that their roots may lie nearer the base of the arthropod family tree.

You’re unlikely to encounter one of these giants since they live in the deep sea, but smaller types (usually only around a 1cm long) are found on most rocky shores, where they feed on bryozoans and hydroids.

This one is from around Franz Josef Land, an archipelago in the Russian Arctic. Several people dropped hints to the genus – in particular Hilary, Chris, Wouter van Gestel, Daniel Calleri & Dan Jones, but Andrew Taylor just came out with it: Colossendeis. The clue there is really in the size.

However, this is a tricky one to narrow down to species. There is an online key to the pycnogonids but unfortunately it’s not totally comprehensive. That said, this species is represented in the key and it’s actually quite distinctive because of its huge proboscis (N.B. the head points upwards in this specimen), quite compact almost disc-shaped body and lack of eyes.

These characteristics match the description for Colossendeis proboscidea (Sabine, 1824), which is more commonly known as the Blind Pycnogonid. Now I want to find out who collected this specimen and donated it to the Dead Zoo back in 1899.

There weren’t too many Arctic expeditions prior to 1900 and this specimen is almost certainly from one of those few. It could possibly be from the Austro-Hungarian North Pole expedition. In 1872 they discovered Franz Josef Land and in 1874 named one of the islands in the archipelago McClintock Island after the notable Irish Arctic explorer Francis Leopold McClintock. It’s not impossible that they would have sent specimens to McClintock or the Museum in Ireland, so it may be time to hit the books to see if I can find any more information!

 Friday mystery object #356 answer

Last week I gave you this rather improbable-looking fuzzball to have a go at identifying:

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Initial consensus on Twitter suggested that it was some kind of taxidermist’s mash up of a tenrec / shrew / weasel and fox. Particular favourites were:

and:

A similar theme emerged in some comments on the blog, but a useful rule of thumb was shared by ch:

Anything that weird looking is either a taxidermists joke or comes from Madagascar- you’d need to look in every ‘nouc’ and cranny to identify this weasily overlooked carnivoran.

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Madagascar is well known for weird animals, since the island became isolated from the Indian subcontinent over 85 million years ago, allowing a unique variety of species to evolve and fill the ecological niches present. The oddities present include the Aye-aye (a mammal trying to be a woodpecker), the Fossa (a mongoose trying to be a cat) and the Web-footed tenrec (a tenrec trying to be an otter).

Of course, ch left an additional clue hinting at the correct identification (‘nouc’) which was picked up on by several others. There were also plenty of people on Twitter who recognised this distinctive animal.

The mystery object is a Falanouc Eupleres sp. Doyère, 1835 – notice the sp. There are two species of Falanouc – Eastern (E. goudotii) and Western (E. major), but this species split was only recognised in 2010. Therefore, it’s very difficult to know which this one is, especially without details of where in Madagascar it was collected.

Assuming it was collected in Madagascar. I say that, because it was purchased from London based supplier Gerrard & Sons. This means it could have been acquired from London Zoo, since Gerard had a relationship with the Zoo and often got dead specimens from them.

It’s also tricky to identify the species from morphology, since the differences between the species are most noticeable in the skull. The fur colour can provide a clue as well, but 100+ years of being on display in a gallery illuminated with daylight means the colour is pretty much guaranteed to no longer be as it was in life.

So I think we may have to leave it there, unless I can find any additional information about the specimen in the Dead Zoo’s archives. Whatever the species, I think this mongoose-like insectivorous carnivore with a fox-like body and shrew-like face is as charming as it is improbable.

Friday mystery object #349 answer

Last week I gave you this long, pink, wrinkly specimen to have a go at identifying:

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There was a lot of discussion about whether it has limby bits, fins, flaps left over from damage during preparation or some other unnamed and dubious appendages. I’m relieved to confirm that it has limbs – albeit rather reduced limbs.

 

The limbs are important, since they allow us to rule out all the legless groups of similar critters, like Caecilians (limbless amphibians), Synbranchidae (swamp eels), Amphisaenidae (worm lizards) or of course snakes (not that any self-respecting snake would have a face that looks like it belongs to a poorly made sock-puppet).

The state of the legs, especially the very reduced state of the front limbs, also allows us to rule out a variety of Olms, Sirens and other Salamanders – except for one odd little genus called Amphiuma.

There are only three living species of Amphiuma – the One-toed, Two-toed and (believe it or not) Three-toed. Someone in the past hedged their bets and labelled the mystery specimen as follows:

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Since the Three-toed salamander is Amphiuma tridactylus Cuvier, 1827 and the Two-toed is Amphiuma means Garden, 1821 this label is misleading.

The Three-toed salamander does have three visible toes on the forelimb and this specimen clearly doesn’t – with just a vestigial wriggly bit (that doesn’t make it the One-toed salamander however, as they are smaller and they have an even more reduced hind limb). So this is the Two-toed Amphiuma means.

 

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Amphiuma means, Virginia, United States. Image by Brian Gratwicke, 2010

 

Finally, it might be a bit confusing that the mystery object is a pink thing, while the living animal is a mottled muddy colour. That’s just an artefact of it being preserved in ethanol for the last 125 years. Trust me, no-one looks good after that much exposure to alcohol.

Friday mystery object #343 answer

Last week I gave you this mystery skull from the Ulster Museum to have a go at identifying:

If you’re a regular follower of Zygoma then you may have seen some of my previous posts talking about the skulls of the various smallish carnivores like mongooses, mustelids and viverrids. Generally though, mongooses have a more domed region above the eyes, while mustelids have a shorter snout, so this is most likely one of the viverrids.

It’s a difficult one to get down to species, since it’s from a group of carnivores that have have a fairly uniform skull shape, so it takes some detailed investigation to work out exactly what we’re dealing with. However, as I have talked about before (and as palfreyman1414 remembered), there’s a very helpful identification guide developed by some French researchers which summarises some of the most useful characters to use in identification.

Most useful to my mind is the matrix of characters that allows you to narrow down the possibilities until you’re left with the most likely species (watch out, the security certificate has expired). Once you’re down to a few possibilities based on those specific characters it can help to check the specimen images on the Animal Diversity Web which lets you get a better idea of overall shape and things like tooth form.

As it turns out, my 270th mystery object also provided a useful image for comparison:

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The reduced upper second molar (or M2) and the shape of the M1 in this specimen from the Grant Museum of Zoology is remarkably similar to the Ulster Museum specimen and it turns out it’s also from a species that made it to my shortlist using the matrix. So I’m fairly sure that this is an Abyssinian Genet Genetta abyssinica (Rüppell, 1836).

To give you an idea of what they look like, here’s a Common Genet in Wrocław Zoo by Guérin Nicolas, 2008

Well done to everyone who worked out we were dealing with a genet, but particular props to palfreyman1414 who was spot on when he said:

I’m wondering if, … this is related to the Abyssinian thingy you spent hours checking on from a complicated table of characteristics across 27 species…

Well remembered palfreyman1414, well remembered…