Friday mystery object #301 answer

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

mystery301bmystery301a

There were a variety of answers, but the first few took this as a worn canine tooth, presumably due to the respectable size and robustness. However, consensus shifted to this being an incisor, meaning it would have to be from a large animal – which is spot on. Moreover, it’s a large animal that was once resident in Ireland.

After that there were a variety of ideas brought up, from all manner of beasts including Sheep, Badger (or perhaps Pine Marten since a cryptic M.m. from the Irish fauna could be either Meles meles or Martes martes), Cave Bear, Coyote, Wolf and even Human. There was one just correct identification however, by Tony Morgan who recognised it as a Hyaena incisor.

It is in fact the lower left third incisor (or i3) of Crocuta crocuta (Erxleben, 1777) – the tooth you can see in this (very gnarly) Hyaena mandible, although it’s much less worn:

Hyena mandible

Hyaenas have an incredibly thick enamel layer on their teeth which creates a distinct neck on the incisor where it stops, which is further defined by the root of the tooth bulging laterally below – presumably to help deal with the forces of prey capture and perhaps the Hyaena’s impressive bite strength.

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The robust skull of a specialist bone-crusher

You probably don’t think of Hyaenas as being native to Ireland, but until 39,000 or so years ago they ranged right across Eurasia, including those parts of Europe which were to be cut off by changing sea levels to form Ireland and Britain.

It’s strange to imagine a species normally associated with the African savanna strolling around the Emerald Isle, but it’s worth remembering that the world is a constantly changing place and wildlife moves around to cope as the environment alters. Borders and boundaries are very human concepts and other species only pay attention when you have a genuine barrier, like an ocean, a mountain range or (if you’re a Dormouse) a break in the tree canopy.

That’s one of the problems with current climate change compared to past climate variations. The speed of change is so great that some species don’t have time to move into new habitats and there are fewer suitable habitats available, because humans have cleared them for farming or building. Meanwhile, some other species can find suitable habitats and are able to move – but they will then often be considered an invasive pest. Now  the chances of Hyaenas returning to Ireland are pretty slim, but if they did I expect most people wouldn’t be too pleased, although you never know…

Kevin Richardson kisses hyena. Image by Kevin Richardson, 2007

Kevin Richardson kisses hyena. Image by Kevin Richardson, 2007

Friday mystery object #300 answer

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

mystery300

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 #278 answer

Last week I gave you this mystery object from the Grant Museum of Zoology to get your thoughts on:

mystery278

Most people spotted that this was a canid of some sort – but there was a lot of discussion about exactly what sort.

Allen Hazen made an interesting observation about the reduced second molar (missing in the specimen, but the socket shows that it was there and smaller than you’d expect from most dogs), plus the remarkably convex facial profile. Useful observations that have a bearing on the identification.

The short and broad muzzle, combined with the convex skull and distinctive molar morphology led Latinka Hristova to suggest Dhole, an identification agreed with by Lupen, palfreyman1414, Richard Lawrence, joe vans, Henry McGhie – and myself as it turns out.

Dhole (Cuon alpinus) by Kalyanvarma

Dhole (Cuon alpinus) by Kalyanvarma

The Dhole Cuon alpinus (Pallas, 1811) is an endangered Asiatic Wild Dog, that hunts in clans and feeds on a variety of medium to large mammals that are usually killed after an extended chase.

I’d not seen the skull of one of these before, but I was aware that they have a convex profile, so it was my immediate suspicion when I saw the mystery object and the species was confirmed by the unusually simple structure of the first molar and very reduced second molar, which are almost cat-like in their adaptation for shearing meat.

All in all, an exciting skull to find – and there are other unidentified canids in the same box that I’m itching to take a look at, so keep your eyes peeled for more mystery mutts.

Friday mystery object #272 answer

Last Friday I gave you this skull to identify:

mystery272

It was a bit of mean one, because although the family is fairly distinctive, it has poor species representation in online resources or indeed the literature.

The cranium is quite low and long, with some similarities to an otter, but the rostrum (or muzzle) is a bit too narrow and the teeth aren’t quite the right shape. Also the orbits are orientated more vertically, whereas otters have orbit that are at more of an angle so the eyes are closer to the top of the head.

The overall shape, dental configuration and median lacerate foramen all suggest it’s a member of the Herpestidae.

Narrowing down the species was a step too far however, after all, there are around 34 species spread across Africa, Madagascar and Asia and Europe and they are generally quite similar in cranial morphology, with only a few species having good descriptions of the skull.

To help challenge the lack of images of mongoose crania online, I’m pleased to say that this specimen does have an identification – it’s a Ruddy Mongoose Herpestes smithii Gray, 1837. While the name Ruddy Mongoose makes it sound like it’s annoyed me, it actually refers to the reddish-brown of its coat.

A Ruddy mongoose from Daroji wildlife sanctuary in Karnataka, India. By Kalyanvarma, 2009

A Ruddy mongoose from Daroji wildlife sanctuary in Karnataka, India. By Kalyanvarma, 2009

This species is endemic to India and Sri Lanka, where it lives in dry, forested hills and feeds on pretty much anything it can get hold of, from snakes to bird eggs. As with other mongooses (or should that be mongeese?), they have a mutation that prevents snake neurotoxins from bonding at receptor sites, meaning that they are immune to some types of venom – pretty handy if you’re going to eat snakes!

Friday mystery object #262 answer

Last Friday I gave you this pretty characteristic mystery object from the Berlin Museum für Naturkunde to try your hand at identifying:

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There were lots of great comments – I must apologise for not responding to many (and for posting the answer to this mystery object so late), my excuse is that I’ve had an insanely busy week finishing up my old job at the Horniman Museum and Gardens and then getting started in my new job at the fantastic Grant Museum of Zoology at University College London (more to come about my big move). I also got started on a really interesting project looking at Gorilla osteology and I’m feverishly trying to prepare a training workshop on identifying natural materials for next week.

Back to the object. Several of you noticed the presence of a baculum (or penis bone) which shows us quite definitively that this was a male animal.

Panda penis bone (baculum) from the Berlin Museum für Naturkunde

It also suggests that the specimen was prepared and mounted without the prudishness that many historical mounts were affected by (see Jack Ashby’s comments about this in his post on the Grant Muesum’s Ringtail).

Many of you also correctly recognised that the plantigrade (or flat-footed) posture, short tail and robust build suggested a bear of some sort.

Panda hind limb bones showing plantigrade foot

The distinctive sagittal crest was the final feature needed for identification for some of you to work out that this is the skeleton of a Giant Panda Ailuropoda melanoleuca (David, 1869).

Panda skull side view

Panda_skull_top

I tend to think of Panda skulls as looking like a cross between those of a Hyaena and a Gorilla, which makes sense when you consider the adaptations of the jaw musculature required for the Panda to process the large volumes of tough bamboo needed to provide enough energy for survival. The bone of the skull has to be able to manage the large forces produced by all this chewing, resulting in a big and robust sagittal crest, a thick and deep mandible and really deep muscle scars on the coronoid process.

These are all features you also see in big chewers like the Gorilla and Hyaena, but not in rodents and ungulates – I think this reflects the difference between groups that rely on temporalis muscle (which runs along the side of the braincase) in chewing compared to the masseter muscle (which attaches to the zygomatic arch or cheekbone).

The final clue to confirm that this is a Giant Panda is the ‘thumb’ on the front limbs:

Panda_thumb_1

Panda_thumb_2

This handy (excuse the pun) extra ‘digit’ is actually the radial sesamoid bone of the Panda’s wrist, that has been commandeered by evolution for use as a bamboo holder. There are a few other species that have done weird things with wrist bones to gain a digit, but this is clearly not a Mole or Elephant and Red Pandas have a much longer tail.

I hope you enjoyed some of the interesting bony features of this specimen – it’s great to have a chance to see under the surface of such an iconic animal!

Friday mystery object #245 answer

Last Friday I gave you this guest mystery object from Dr Nick Crumpton at the NHM:
mystery245
Here’s what Nick had to say about it:
So when I first picked it up I thought – embarrassingly now – that perhaps it was something a bit pinniped-like but then the teeth didn’t match that idea at all so I reverted to thinking it was a bit more doggy.
Irritatingly, it was a juvenile so that scuppered size-based guesses, and ruled out taking too much information from the posterior, mandibular teeth. Also, the skull was darn cute, with a shorter snout than an adult would possess.
I had a couple of ideas from looking at the width of the zygomatic arches, but that lack of a parasagittal crest got me all twisted around. And time was tight for what we needed it for!
My esteemed colleague Mr Garrod was the first to push me in the direction of a wolverine, but I’ll leave it to Paolo to show how he managed to ID the little critter and save the day – although it looks like a bunch of people on here already managed that! Love the bone-banter. 😀
We’ve discussed in the past how the skulls of juvenile animals can be misleading and for this species a number of the features you would immediately recognise in the adult are absent in this juvenile. Therefore I’m not that surprised the suggestions in included Arctic Fox, Sea Otter, Common Seal and Spectacled Bear, in addition to the possibility of Wolverine.
Wolverine cranium

Wolverine cranium for comparison

Despite the juvenile dentition, the blade-like molar and 3rd premolar, and robust second molar were indicative of a carnivore with a specialisation for eating bone and the breadth across the zygomatic arches indicated something with a powerful bite force.
Wolverine dentition is remarkably robust, since they often scavenge bone and in the winter they need to feed on meat that has frozen solid. They have a wide skull (see above), but the relatively large upper molar is at right angles to the 4th premolar, which has a cleft that the 3rd premolar nestles into.
This is rather different to the much straighter dentition of the mystery animal, which is distinctly more cat-like, albeit with too many teeth. That narrows it down to one of the Hyenas. From there it becomes a bit more difficult and the fact it’s a juvenile throws a bit of a spanner in the works, but if pushed I’d probably opt for Spotted Hyaena Crocuta crocuta (Erxleben, 1777).
So well done to Chris, Lena, palfreyman1414, Allen Hazen and henstridgesj who all came to the same conclusion.
Finally, a big ‘thank you!’ to Nick for posing a decent challenge!