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 #295

For many of you, last week’s mystery object answer was a little disappointing, since I was unable to pin down what the specimen was. Normally with birds it’s not so difficult, because of useful resources like skullsite.com, but the fact is that some bird groups are still quite poorly represented in collections and finding comparative material is difficult, especially online.

The most frustrating thing about last week’s object is that it did once have a label, but at some point in the past it was lost, so the only information with the specimen now is this:

mystery295_label

However, this label does offer a glimmer of hope, since it identifies the specimen as being from a particular collection and that can often mean there will be more information somewhere.

As it turns out, this specimen is one of several that were purchased in 1867 from an auction of the collections of Dutch anatomist Theodoor Gerard van Lidth de Jeude. This is helpful because auction catalogues can contain information like the species names of the specimens being sold. It is particularly helpful when you have the original catalogue with annotations about the specimens bought by your institution.

Fortunately, at the Dead Zoo we have the auction catalogues. Unfortunately we bought quite a lot of stuff, so working out which of the specimens our mystery object represents is still quite a lot of work.

However, if other specimens from the auction have their names and numbers, it should be easier to narrow down the ones that lost their labels. It also can also help to have an identification of the specimen to track back to the catalogue, which is why I was keen to get your thoughts last time and why this week’s mystery object is from the same collection.

So can you help me work out what species this skull belonged to?

mystery295

No need for cryptic clues, but if you want to show off your taxonomic prowess you could always offer the 1860’s scientific name or the name of what you think it is in Dutch.

I hope you have fun with this one!

Friday mystery object #293 answer

Last Friday I gave you this unidentified specimen from Dublin’s Dead Zoo and asked you to help me work out what it was:

mystery293

The response was incredibly helpful and it was great to see that most of you were drawn by the morphology to make a similar identification to me.

The fact that it’s from the family Anatidae (the ducks, geese and swans) was immediately noticed, and from there the likely genus was quickly narrowed down to Branta, based on the morphology. This is the genus containing the ‘burnt’ geese (that’s what ‘branta’, derived from the Old Norse, means), which includes: the Brant Goose; Barnacle Goose; Canada Goose; Cackling Goose; Red-breasted Goose, and Hawaiian Goose.

However, the nominate examples of all these species (that means the ones derived from the type on which the species name is based) are either the wrong shape or a bit too large to have this skull, which you can see by checking them on the excellent Skullsite by Wouter van Gestel.

The closest species in terms of morphology are the Cackling Goose (B. hutchinsii), Canada Goose (B. canadensis) and Barnacle Goose (B. leucopsis), but it turns out that there are various subspecies of each and one (that was previously recognised as a subspecies of Canada Goose, but which is now considered a subspecies of Cackling Goose) is rather small, as flagged by the subspecies name minima.

This smallest subspecies seems to fit both the morphology and the size very well, so I’m quite confident to identify the mystery specimen as the Small Cackling Goose Branta hutchinsii minima (Ridgway, 1885).

640px-small_cackling_goose_brood

A family of Small Cackling Geese, by Tim Bowman, USFWS, 2003

So thanks to you all for helping me to narrow down where in the Anatidae to start looking! More mysteries from the Dead Zoo next week.

Friday mystery object #293

This week I have the first of what I hope will be many mystery objects from my new job as zoology curator at the National Museum of Ireland:

mystery293.jpg

I haven’t quite got myself a proper photographic set up yet, but I hope this photo of an unidentified skull in the collection will be good enough for you to be able to help me work out what species it belongs to.

As usual you can leave your thoughts, questions and suggestions in the comments section below. Have fun!

Friday mystery object #291 answer

Last week I gave you this skull from the Grant Museum of Zoology to identify:

mystery291

I thought this would be a fairly easy one and so I wasn’t surprised when Chris was straight in with a correct identification, in a suitably cryptic manner of course.

The huge open sinuses inside the orbit and openings around the auditory bullae (as spotted by palfreyman1414) immediately suggest that this is an animal that dives deep underwater, as the large openings help prevent pressure from building up inside the skull. The shape of the teeth are another giveaway that this is a fish-catching mammal in the Order Carnivora. It is of course a seal.

But what kind of seal? There are 33 species of pinniped, so there are a few options, although the large and distinctive species like Walruses can be ruled out for obvious reasons. In this size range and with multicusped teeth like these we’re looking at one of the true seals (the Phocidae) at the medium to small end of the size range.

When you start looking at the skulls of seals in this range, you need to look  closely. It lacks the flat top of the head and steeply sloping profiles following the nares of a Grey Seal, plus the interorbital distance (the distance between the eyes) is much smaller.

It lacks the inflated nasal region of the cold water Bearded Seal, Ribbon Seal, Ringed Seal and Harp Seal, which need well developed nasal turbinates to help warm the air they breathe in. It also lacks the deflection of the zygomatic below the orbit that is seen in the smaller species like the Caspian and Baikal Seals.

Overall the morphology is most similar to either the Spotted Seal or Harbour Seal, but picking between the two is tricky, especially since the Harbour Seal has around five subspecies that vary somewhat in size and shape of things like the auditory bullae. There is a list of characters that can be used to distinguish between the skulls of the two species by John J. Burns in the Encyclopedia of Marine Mammals. Using that as a guide I think this is a Harbour Seal Phoca vitulina Linnaeus, 1758.

Thanks to everyone who had a go at identifying this – I hope you had fun with it!

Friday mystery object #291

Today’s mystery object is a fairly straightforward one from the Grant Museum, although I’m hoping that we’ll get a species identification for the specimen. Any idea what this is?

mystery291

As usual, a nice cryptic clue would be appreciated so that we can have some fun and not give away what it is too soon for those who are developing their identification skills. Enjoy!