#MuseumSelfie

Today is #MuseumSelfie day as part of #MuseumWeek, so here are few selfies of me trying to recreate the look of specimens from the Horniman’s natural history gallery.

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Utterly ridiculous, but fun nonetheless. If you have some similar selfies why not link to them below in the comments section? After all, I don’t want to be the only one looking silly!

 

Friday mystery object #219 answer

On Friday 7th Feb I gave you this mystery skull to identify:

mystery219

The post got lots of activity from both regulars and biology students from the University of Chicago Laboratory School, which means there were lots of helpful comments!

The specimen was quite clearly from a rodent, due to the paired incisors, but there are a LOT of different rodents out there.

The type of rodent was narrowed down by bugblokenz who suggested the skull was from a squirrel of some sort and Jake pointed out how we know that is the case – the specimen has a spiky postorbital process:

rodentpostorbitalprocess

The presence of a spiky postorbital process (see top skull) suggests that it was from a type of squirrel. Most other rodents either lack this process (see bottom skull), or the process is more stout and blunt.

Narrowing it down to a squirrel is helpful, but there are still around 285 different species to choose from and many squirrels have very similar skulls. This is where the real challenge lay, especially since it clearly wasn’t the British Red Squirrel Sciurus vulgaris or the more widespread Eastern Grey Sciurus carolinensis, as I showed you on Friday 14th. Other suggestions included the Southern Flying Squirrel Glaucomys volans (which is a bit on the small side) and Eastern Fox Squirrel Sciurus niger (which has a really interesting method you can use to identify it).

The relatively narrow zygomatic breadth, combined with a relatively wide breadth between the orbits suggests a ground squirrel of some sort, which many people recognised, leading to suggestions of Poliocitellus frankliniiSpermophilus sp., Otospermophilus sp. and Tamias sp. – for which this useful reference provides some great comparative specimens (huge thanks to Crispin for sharing this).

However, none of the North American ground squirrels quite matched up, with the closest suggestions of Otospermophilus variegatus or Poliocitellus franklinii still being different in a variety of ways, particularly in relation to the width of the skull, relative zygomatic breadth and shape of the postorbital process.

After much consideration it came to me that we may be looking on the wrong continent and it turns out that African ground squirrels are more similar to this specimen. Fortunately, there is a very useful resource providing images of specimens of African rodent species available through the Belgian Biodiversity Platform. This fantastic site has enabled me to make a reasonably confident identification of Striped Ground Squirrel Xerus erythropus (Geoffroy Saint-Hilaire, 1803).

Striped Ground Squirrel (Xerus erythropus) by BOISSEL Philippe

Striped Ground Squirrel (Xerus erythropus) by BOISSEL Philippe

I’d still like to get my mystery skull to a comprehensive physical collection, just to make some fine detail checks (there are some issues with the shape of the posterior margin of the palate I’m not 100% happy about), but overall I’m happy with this – but please let me know if you think I’ve missed something!

Big thanks to everyone who has contributed their ideas on this specimen – let’s see what I can find for you to identify this coming Friday…

[Further information available in this species description PDF]

Friday mystery object #215 answer

Last Friday I gave you this perplexing specimen to identify:

mystery215

It was labelled as a Crab-eating Raccoon, but the facial region is much longer and narrower than other examples I’ve talked about, and it’s much less robust:

Crab-eating Raccoon skull

Now the gracile build could just be because it’s the skull of a juvenile (which is what it looks like), but juveniles have shorter and relatively broader facial regions than adults, so that doesn’t work. Even the less robust jaws of the Common Raccoon are too short and wide for the mystery specimen (which I think may discount Robin Birrrdegg’s suggestion).

Another crab-eating option was suggested by Daniel Jones who thought Crab-eating Fox. Now the overall proportions are a good match for this species, but there’s a problem. If the mystery object had teeth this would be much easier, but there are the holes in the maxilla to give us clues about the shape and size of the molars and as Allen Hazen pointed out:

Three triple-rooted teeth. Are these three molars, or is the last premolar triple-rooted? If it’s three molars… Canids (usually) only have two upper molars…

This is indeed the case and so this skull can’t be from a Crab-eating Fox.

On a different tack, henstridgesj suggested that it might be a civet of some sort, pointing us in the direction of mystery object #143 for comparison:

African Civet skull

But again this really doesn’t look right – in particular the civets have a narrow constriction behind the orbital process, which is lacking in the mystery specimen. This was noticed by henstridgesj and he suggested that the closest option he’d been able to find was a Coati:

Coati skull

Now the specimen of Coati above is a mature male that was mystery object 54 and it doesn’t look much like our most recent mystery object, but on checking the skulls of juvenile and female Coatis I realised that this is probably the best option so far.

I still want to check some more specimens, but I’m really grateful for everyone’s input on this specimen – it’s been a challenge and you have all helped immensely!

I’ll  be back with another mystery object next Friday, but until then I’d like to wish you all a thoroughly enjoyable festive season!

Friday mystery object #214 answer

Apologies for the lateness of the FMO this week, my excuse is a rather apt bout of illness, where some of the alveolar bone of my mandible has been lost due to an infection, leaving me feverish and thoroughly miserable.

But enough about my me, this is the mandible I’m supposed to be talking about:

mystery214

There was a fascinating discussion about the possible identification in the comments last week, so a big ‘thanks!’ to all of the contributors who provided their informative observations (too many to mention everyone by name!). A mustelid of some sort was quickly agreed upon and the general consensus moved towards an otter of some kind, before starting to drift away again.

Two comments in particular were particularly pertinent. The first was from Daniel Jones:

Alright . . . instantly the foramina on the mandible anterior to the premolars scream Otter! However, the incisors don’t. The incisors just lateral to the canines should be larger and longer than any of the other incisors among the otters (even the Asian Short-clawed Otter).

Now my identification for this specimen was indeed Asian Short-clawed Otter Aonyx cinerea (Illiger, 1815), so this comment made me a bit concerned. However, on checking some images online I realised that the long lateral incisors are present in the premaxilla, but not the mandible – an easy detail to miss.

The second comment was by Allen Hazen:

Anyway… The talonid on the first molar of the one in the picture is BIG.

The reason I found this comment useful was that the long and broad talonid (that’s the flatter grinding section on the molar) is what confirmed the Asian Short-clawed otter identification for me (although the small size was a good first clue).  This became quite clear from an image on the Otter Specialist Group webpage.

The Asian Short-clawed Otter presumably has this large talonid because it has a diet mainly composed of crustaceans rather than fish, and it needs the extra crushing area on the molar to crack open tough exoskeletons.

Who would think you’d get teeth as formidable as these on such an adorable little critter?

Friday mystery object #214

This week I have a stray mandible for you to have a go at identifying:

mystery214

I think I know what it’s from, but I’d appreciate your thoughts. As usual you can put your thoughts, comment and questions below. I can’t wait to hear which critter you think it might be from!

 

Friday mystery object #213 answer

Last week I gave you this interestingly shaped piece of bone to identify:

mystery213

Jake, Elisa, henstridgesj, Hew Morrison, Robin Birrrdegg, Daniel Jones and Daniel Calleri all made a correct identification of this being part of a sternum, a sternebrae or more specifically a manubrium from a fairly large (yet possibly juvenile) ungulate. This was all correct and the final piece of the puzzle is the species, which is actually a smaller Deer than most people were expecting. It’s from an immature male Fallow Deer Dama dama (Linnaeus, 1758) collected from Knowle Park in Kent.

Here’s what it looks like with the rest of the sternebrae (which are the individual elements of bone that make up the sternum, like vertebrae make up the spine) that I could find for the specimen:

Sternum of immature male Fallow Deer Dama dama

Sternum of immature male Fallow Deer Dama dama

So it was indeed the manubrium – the top sternebra which in humans articulates with the top ribs and clavicles, but which here would only articulate with the top ribs, because ungulates don’t have clavicles (as I’ve discussed before). Here’s a human sternum for comparison:

Human sternum

Human sternum

So well done to everyone – I hope you enjoyed the challenge!

 

#bonegeeks

There are some great resources online for finding images of comparative material for skulls, but the postcranial skeleton tends to be quite badly represented online even for common species. I’d love to change that, but it’s a big challenge for one person.

Paramastoid process of Pig (Sus scrofa)

Paramastoid process of Pig (Sus scrofa)

That’s why I’d like to set up #bonegeeks on Twitter (and maybe on other social media as well). The way I see it, people who have access to skeletal material could easily take snaps of bits of postcrania from known species (preferably with something for scale) using their phone and share the image to Twitter, Tumblr or Facebook with the name of the species and the bone (and perhaps where the specimen is held).

With the #bonegeeks tag it should be easy to collate images and hopefully start building up a comparative collection of images to make identifications easier.

It could start with a bone of the week to get the seldom depicted bones better represented and I’m sure #bonegeeks would be willing to respond to requests if there were particular bones that someone wanted to see.

I wonder if this could work… shall we give it a go and find out? Please add your thoughts on this idea in the comments section below or on Twitter using the #bonegeeks hashtag.

Oh and here’s how the idea got started: [View the story “#bonegeeks” on Storify]