Last week I gave you this rather nice, but somewhat tricky mystery object to have a go at identifying:
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.
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:
…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).
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.
Last week I gave you this specimen from the Dead Zoo to have a go at identifying:
It was a bit of a tricky one, since the specimen has been sectioned down the midline and the bone of the maxilla has been removed to show the roots of the teeth.
However, many of you were stuck at home and had a chance to get into detail in the comments. There were some fantastic answers where the features were discussed, so I think it’s well worth sharing some of them:
We are confined at home, so we searched together with my 5 years old daughter. Here are our thoughts :
– foramen magnum in a downward position, low-crown teeth, bony part behind orbite, orbites facing toward the front, so we are dealing with a primate
– but a special primate because the orbites are open to the temporal fossa. And also it has a long snout with the orbites below the nasal bone. The orbites are not big enough for a nocturnal monkey. And also the very special lower incisors in horizontal position, also know as teeth-comb. We think it is a lemur-like animal.
The brain case is not round enough for a Lorisidae. We could not find pictures of all the lemur and sportive lemur species. But we saw the picture of a skull of the cat-ish one and it fits very well.
Second thoughts: we cannot quite see this but in my own notes on lemur;
Canine often incisiform and procumbent, arranged laterally with incisors in toothcomb, creating array of 3.
Ist mandibular premolar often caniniform
This would then be 3 premolar, 3 molar and therefore not Varecia but more probably Eulemur….
While some lemurs don’t have upper incisors, this one has small peg-like ones. A Ruffed lemur (Varecia variegate), while having the same dentition, has more of an orbital thickness.
Since the skull has been dremeled out, I am not sure how much of a diastema was between the canine and upper premolars. If there was one there, I will vote for a Ring tailed lemur (Lemur catta), female, because of the smoother occipital and more slender lower mandible. The size fits as well.
These comments all highlight features of the skull that belong to lemurs, but there is a little confusion caused by the bone removed from around the teeth.
Ring-tailed Lemur was the most popular answer, but the diastema (or gap) between the upper canine tooth and the first upper premolar that katedmonson mentioned would not be present on this specimen, even if the bone was still there. Also, that lower first premolar has a fairly simple conical/triangular shape with just one cusp – which makes it caniniform, as mentioned by steveryder.
Rather than the Ring-tailed Lemur, this is the skull of a Ruffed Lemur Varecia variegata Kerr, 1792. I think it’s probably from a female or young animal (or both) as it’s more gracile than some other specimens I’ve seen. This accounts for the reduced orbital thickness, slender mandible and smoother occipital mentioned by katedmonson.
Black and white ruffed lemur by Charles J Sharpe, 2018
I should say, on Twitter Michael English and Gabriella Κογντογριδη also recognised this as a Ruffed Lemur. Worth mentioning that if you use Twitter and you like identifying skulls (well OBVIOUSLY you like skulls if you’re reading this) then it’s well worth checking out the #GuessTheSkull hashtag started by Yara Haridy.
A new mystery object next week – stay safe and healthy!
This week I’ve gone for a slightly more artsy image for the mystery object than usual:
You can click on the pictures to get a large version, which you might find useful.
I foolishly forgot to measure the specimen or include a scale bar, so I’ll update with a length as soon as I get back to the specimen. Sometimes it’s nice to rely just on morphology, so let’s see if anyone can work out what this is before I provide more information. [UPDATE: it’s 84mm long]
Last week I gave you this unidentified skull from Dublin’s Dead Zoo to have a go at identifying:
It didn’t prove too difficult to narrow it down, with everyone recognising it as a mustelid and Rémi immediately recognising it as being one of the Martens. But salliereynolds and Chris managed to get it down to the species, which is a bit of work.
There are around seven living species in the Genus Martes, although the total number varies depending on the sources you read. They have very similar skull shapes, the same dental formula and very similar tooth shape. In my experience the main feature to differentiate them lies in the auditory bullae.
There are some decent online resources with images of Marten skulls, so it is possible to get a handle on some options. Each bulla is a 3 dimensional structure that is inflated in subtly different ways that are really hard to describe.
In a previous post I had a similar specimen (the same species as it happens) as a mystery object and I compared some bullae, but alas the image I referred to has since been removed. However, the important point is that there’s only one of the Martens that seems to have an outermost lobe that has a well-defined anterior sulcus (a fissure towards the front edge). This feature makes me think that this is a European Pine Marten Martes martes Linnaeus, 1758.
However, it didn’t take long for you to work out what it was and, if I’m honest, you beat me to it, so well done on that and thanks for your contributions!
Clearly it’s a carnivore as it has well-developed carnassial teeth. However, immature animals with a mix of deciduous and permanent teeth can be confusing. It also doesn’t help when the skull shape is still forming.Fortunately, to help narrow it down there is the auditory bulla and that molar tooth just behind the carnassial. The shape of these features suggest that it’s a mustelid.
There was some discussion about badgers and otters, but Bob Church settled it by providing a very useful reference containing this image:
Figure from Long, Charles A. 1965 Comparison of Juvenile Skulls of the Mustelid Genera Taxidea and Meles, with Comments on the Subfamily Taxidiinae Pocock. American Midland Naturalist 74(1)225-232.
As you can see, this is an excellent match for the mystery specimen, both in dental morphology, auditory bulla shape and even scale, allowing us to make a confident identification of juvenile American Badger Taxidea taxus (Schreber, 1777).
So well done to Jeanie, katedmondson, Bob Church and Rémi, and my thanks to you all for your help in identifying this tricky specimen.
Last week I gave you this unidentified skull from the collections of the Dead Zoo in Dublin to have a go at identifying:
I wasn’t sure how difficult this would be – I know carnivore skulls can be a bit of a challenge, but this is a critter that’s come up as a mystery object a couple of times before. As such, I did expect a few of the regulars to recognise this, but it proved more difficult than I thought.
That said, nobody got it. Well, somebody got it, but that person was nobody with the simple statement:
I’m guessing coati 🤔
Of course, there’s more than one kind of coati, in fact there are four: the Ring-tailed, the White-nosed (or Coatimundi), the Eastern mountain and the Western mountain.
The mountain coatis are in the Genus Nasuella and they have a very narrow and gracile rostrum (that’s the muzzle area) – so this is not one of them. The other two are in the Genus Nasua and they are recognisable by their upward tilted nasal area and their upper canines which are very tusk-like – projecting forward and triangular. The mature adults of both species have a big sagittal crest, which this lacks, but that’s probably because it’s not a mature adult.
The slightly more inflated auditory bullae and the angle of the mastoid process (where the muscles that control the movements of the outer part of the ear attach to the skull) tells me that this is most likely to be the White-nosed coati Nasua narica (Linnaeus, 1766).
I hope that helps in case you need to identify another of these any time soon.
‘Boner’ would of course be an accurate slip, because this is clearly a baculum (aka the penile bone, os penis, os priapi, or oosik in the case of pinnipeds). I don’t think the slip was deliberate though, since I removed a piece of information from the label for the sake of the challenge:
I can only imagine that this baculum was found with some seal bones and was not recognised as being part of the skeleton and therefore removed. There’s no reference to where the rest of the seal bones are, which is bit of a problem if they are in the collection.
I’ve blogged about penile bones on several occasions, since as far back as in 2010. Bacula are often quite distinctive, allowing species identifications based on their morphology. But this particular specimen has proven hard to find good specific comparative material or images (online or in publications) to do comparisons against.
However, from looking at the few seal bacula that do have illustrations in publications, and scouring the internet for articulated seal skeletons with bacula in place, I think it’s probably from male Grey Seal Halichoerus grypus (Fabricius, 1791). If so, this individual would have likely been aged 10 years or over.
This age suggestion is based on the length and robustness of the specimen, which in Grey Seals has been shown to correlate quite closely with age and maturity in the males (Hewer, 1964;Van Bree, 1972). This interesting bit of information aside, I unfortunately couldn’t find the clues that led palfreyman1414 to the Holmesian deduction:
…So, apart from the fact that they are right-handed, have been to Afghanistan, currently work as a haberdasher’s spool threader and have fallen on hard times, I got nothing.
But bacula are informative bones, so I’m sure there is a lot of additional information available from the specimen that I’ve not deduced.
All of you worked out what this bone(r) was, and several people recognised it as being from a seal of some kind, both in the blog comments and on Twitter. There was also a suggestion of Grey Seal from Conor Ryan:
Although I’m no expert on penis size…. I’m gonna guess grey seal baculum, based only on the length. #shlong
Recently I was looking at some skeletal specimens in the Dead Zoo stores, to help with a research enquiry. I came across a drawer of unidentified bones and as you might have guessed, I was delighted. Over the next few weeks I’ll be sharing some of these to get your thoughts on identifications.
To get started, here’s a good one:
Any ideas what bone this is and what animal it’s from? You can leave your ideas in the comments section below.
Last week I gave you this pretty cool skull to have a go at identifying:
As everyone recognised, it’s the skull of a snake. I think that’s clear from those extremely long quadrate bones (highlighted in purple in the top view), with which the lower jaw articulates to allow a huge gape for swallowing prey whole. However, there are a lot of snakes out there – around 3,600 species, which means there are lots of possibilities for the species that this particular skull belongs to.
The side view allows us to rule out quite a few possibilities, since it’s clear from the teeth that this isn’t one of the front-fanged snakes (vipers and elapids).
Rattlesnake skull, with its big front fangs.
The light construction of the skull suggests it’s not one of the constricting snakes, which have much more robust skulls for dealing with the forces generated by the struggles of relatively large prey.
Python skull, with a robust construction for wrangling prey.
The teeth are quite small and although there are a couple of slightly longer ones in the tooth row, they hardly count as real fangs at a paltry 3mm long. So we’re probably dealing with one of the ‘non-venomous’ colubrid snakes (many of these are actually venomous, but lack the appropriate tools to deliver that venom through human skin).
Of course, there are still well over a thousand possible species in the Colubridae – but this is where you have to start ruling out possibilities by comparing the specimen against species that are common and widespread, to begin the process of narrowing down the options.
If you take a look through, it quickly becomes apparent that there is one species that matches the mystery object very closely – even to the position of the slightly larger teeth. It’s a species that has an interesting defense mechanism that jennifermacaire referred to:
…The closest skull I could find is from a snake that likes to roll over and play dead…
This is a fascinating behaviour seen in several snake species, but Jennifer is correct that it is seen in the species that this skull is from – the European Grass snake Natrix sp.
Of course, the story then gets more complicated again, since a couple of subspecies of Grass snake have been elevated to species in the last few years. The Iberian subspecies Natrix natrixastreptophora was recognised as N. astreptophora in 2016 and the subspecies N. n. helvetica found west of the Rhine (including in the UK) was updated to N. helvetica in 2017.
These studies were based on genetics and I’ve yet to see any way of differentiating between these species using skeletal features, so for now the best I can say about this specimen is that it’s Natrix sp. I hope you enjoyed that little slither into the world of snakes, which seems to have opened a bit of a can of worms…
First of all, I’d like to wish you a very happy and healthy 2020!
Last year I gave you this festive-looking beetle to try your hand at identifying:
It was a bit of a tricky one to get to species, since beetles are notorious for their huge diversity, plus they can vary in appearance quite significantly within a species.
James Bryant recognised this as a member of the Buprestidae, which is a family of wood-boring beetles that are commonly known as Jewel Beetles due to their metallic and iridescent colours. In fact, the wing cases (or elytra) of some of the most colourful of these beetles have been used in traditional beetlewing jewellery in the parts of Asia where they are found.
Going beyond the family, the identification katedmonson provided through a great cryptic clue was spot-on (assuming I understood it properly). This particular specimen is an example of Chrysochroa rajah Gory, 1840, but in the collection it is still labelled under the synonym C. chinensis.
This species is one of those with a wide distribution, several subspecies and a variety of different colours and patterns, which can make it hard to identify based on just an image of the overall body (or habitus as it’s referred to by entomologists). Just to give you an idea of what I mean, here’s an example of the same species in the National Museum, Prague:
Blue and green form of Chrysochroa rajah from southern China. Photo by Hectonichus 2010
So well done to katedmonson for getting this tricky identification. Look out for another mystery next week!
Last week I gave you these two genuine mystery specimens from Katharine Edmonson to get your thoughts on:
It was most definitely NOT an easy challenge, and I’m still not sure I know the answer to either, even after looking at every species I can think of that might have similar structures.
These are both clearly teeth, considering the internal details:
One image shows the root area of a full tooth, and one shows a section through a tooth – both of which provide really useful information. For example, the full tooth has a central dentine growth that you often find in animals that deal with a lot of strain on the tooth or where infection has got in (I’ve shown this before in elephant ivory).
The sectioned tooth shows a zone of dentine in the middle that suggests some hard use. Notably, that zone matches the shape of the cross section, so those grooves in the sides of the tooth aren’t from wear – they must be intrinsic to the tooth shape.
Generally, tusk cross sectional shape reflects the shape of the socket (until it gets worn down) – so that gives a pretty good way of narrowing down possible options. For example, I’d discount walrus, since they have an almost rectangular section. Warthog tusks have a section somewhere between the number 8 and a mushroom in shape, and Hippopotamuses have a triangular section to their canines, but their incisors are quite circular in section.
Warthog tusk socket
Then there are wear facets, that can give teeth and tusks a characteristic shape. Hippo canines grow in a corkscrew if unworn, but by rubbing against each other they remain sharp and fresh (like rodent teeth).
This means that teeth and tusks can look weird if the normal wear is disrupted, either by not happening or by happening too much.
There are also unexpected tusks that need to be considered, like the Indian Rhinoceros or dugongs that have hidden tusks.
Of course, some animals have really weird tusks, especially when they’re young or if they’ve experience something that leaves the tusks deformed or altered – which can make identification really hard.
There were a lot of suggestions of Sperm Whale tooth, which is a possibility, but I’ve not seen any that really come close. It may be that both of these are tusks from something more unusual, like beaked whales, but I have looked at a lot of examples of beaked whale teeth and I can’t find any examples that match either of these.
On balance, I think that the first of the tusks may be a Hippopotamus incisor that’s been misaligned with another tooth, causing excessive wear and horizontal stress lines to appear during tooth growth – this is rampant speculation I hasten to add. The second looks a lot more like a Warthog tusk in section than anything else, although the end is more spade-like than I’d expect.
So, after a lot of consideration I’m still uncertain of the identification of either of these, and I would be delighted to hear if you have any more thoughts!
Last week I gave you this really nice skull from the Dead Zoo to have a go at identifying:
It proved a little more tricky than I thought it would, but I shouldn’t have been surprised given the poor quality of the photo and the fact that the cranium isn’t properly seated on the mandible (as pointed out by Allen Hazen).
Of course, that didn’t keep you all confused for too long. The large sinuses and relatively undifferentiated and widely-spaced teeth – except for those large canines – suggest that this is the skull of a some kind of seal.
Jeanie and salliereynolds noted the large, depressed opening over the nasal region, which is definitely one of the most distinctive features of this species. However, it also misled in the first place, with discussion of the possibility of it being from an Elephant Seal taking over for a while.
However, salliereynolds got back on the right track, while on Twitter Ray Chatterji was on the right track from the start with his suggestion:
The Hooded Seal Cystophora cristata (Erxleben, 1777) is really weird – well, the male is. He has an inflatable bladder on its head and one nostril contains a membrane that he can inflate to show off to other Hooded Seals.
I find it hard to think of this as anything other than nature’s attempt at making slightly disgusting balloon animals.
Well done to everyone who worked it out – I have a couple of fun guest mystery objects for you next week!
Last week I gave you this weird, but rather nice object to have a go at identifying:
Most people seemed to recognise it as the tympanic region (that’s the bony ear-related region) of a whale. But of course, I’m demanding when it comes to getting an identification and there are plenty of species of whale to rule out.
The size immediately narrowed down the possibilities – this is pretty small for a whale. But what really gives it away for the small number of people intimate with the cranial anatomy of whales (which goes beyond even my bone-nerdery), is the spongy bone attached to the tympanic bulla (that’s the bulb-shaped bit of bone that houses the inner ear).
This feature is proposed as a possible pressure receptor that’s found in the Pygmy Sperm Whale Kogia breviceps Blainville, 1838. Amazingly, Conor Ryan identified this on Twitter – his handle of @whale_nerd explains everything you need to know.
Kogia breviceps by George Brown Goode, 1887
These toothed whales only grow to around 3.5m, which is pretty small for a whale. They share some features with their much larger Sperm Whale cousins, particularly in relation to adaptations for echolocation.
I was fortunate enough to meet Conor Ryan at the weekend at the Irish Whale and Dolphin Group conference. There were plenty of whale enthusiasts around and it was fantastic to get a chance to learn more about this incredible group of animals from a lovely bunch of passionate people.
While I was there, I also picked up some useful tips on differentiating between species of dolphin, so I may have to share those with you soon…