Friday mystery object #249 answer

Last Friday I gave you this exploded skull from the incredible Galerie d’anatomie comparée et de Paléontologie in Paris:

mystery249

As I suspected, it was a bit of an easy one for many of you, but that provided the chance for some cryptic clue fun.

So my thanks to Agata Stachowiak, Chris, Allen Hazen, henstridgesjClaire Miles and witcharachne who all hinted at an identification of Sloth, more specifically a Two-toed Sloth, I think of the species Choloepus hoffmanni Peters, 1858 as opposed to C. didactylus Linnaeus, 1758, which appears to have a smaller angular process on the mandible and a less broad zygomatic region.

A two-toed sloth (Choloepus hoffmanni) at La Selva Biological Station, Sarapiqui, Costa Rica. By Geoff Gallice

A two-toed sloth (Choloepus hoffmanni) at La Selva Biological Station, Sarapiqui, Costa Rica. By Geoff Gallice

The teeth of Sloths are fascinating, due to their fairly simple rooting and their impressively sharp premolars that look like canines.

These Sloths have an interesting feature of their hair, which has a groove to help support algae, which help keep the Sloth camouflaged. This is pretty handy given the Sloth’s notorious lack of speed with which to escape predators. This may help explain the need for those sharp premolars as well!

Friday mystery object #248 answer

Last Friday I gave you this mysterious leg to identify:

mystery248

It had me stumped for some time and I was hoping that your suggestions might lead me to an identification.

As it turns out, I did indeed get inspiration from your ideas and I think that I may have worked out which species this leg came from.

The first suggestion came from Barbara, who suggested that it might be from a Wombat. This was a great suggestion, since I hadn’t properly considered any marsupials and the robust nature of the leg suggests a heavyset digger. However, the calcaneus (or heel bone) in Wombats is shorter than we see in this specimen and the ungals (the bits at the very end of the toes, where the claws would attach) are longer and more spade-like in the Wombat – an adaptation for digging.

Carlos and Lee Post made some useful observations about the patella (kneecap) and general proportions of the hind limb elements and how they relate to those of other animals – ruling out anything from North America.

Finally, henstridgesj made the interesting suggestion of Capybara, although it appears that the fibula on the mystery object is far too robust to belong to a Capybara. However, I hadn’t thought too much of rodents, so that got me thinking of another possibility:

20140227_143245

The Crested Porcupin Hystrix cristata Linnaeus, 1758 is the third largest rodent after the Capybara and Beaver, and it appears to have similar general proportions of the hind limbs. I’ll need to check against a specimen, but it seems I have a useful direction for investigation – so many thanks to everyone for your suggestions!

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Update March 27, 2015 9:41am

I have now checked the mystery specimen against a Crested Porcupine and they are indeed a match!

wpid-20150327_092925-1.jpg

Friday mystery object #248

This week I have another perplexing mystery object for you, that I’ve found harder to identify than expected:

click to embiggen

I’ve compared it to several specimens in a similar size range and it hasn’t matched any of them well enough to make a confident attempt at identification. Whatever  it is, I don’t have a skeleton of anything comparable in the stores at the Horniman, and it’s a chunky critter with much more robust hind limbs than a Eurasian Badger Meles meles.

Any suggestions on what this might be from would be greatly appreciated!

Friday mystery object #247 answer

Last Friday I gave you this unidentified object to get your opinions on:

mystery247

This specimen has puzzled me quite a bit. The internal structure is a dense honeycomb, that seems too tightly compacted to belong to a bird – plus it’s so big that the only birds it could possibly belong to would be a Moa, Elephant Bird or maybe Ostrich at a push, and I compared this against two of these three possibilities:

mystery247b

So, it’s mammalian and large. It’s also clearly a metatarsal or metacarpal, based on the shape of the articular surfaces.

It’s not shaped quite right for a one or two toed animal so the it seems that the variety of suggestions along those lines of Hippopotamus, Rhinoceros and Elephant are most likely to be in the right area.

I did compare this to Hippo feet and an Elephant hindfoot and drew a blank, so that leaves an Elephant forefoot or a Rhinoceros foot. My best guess would be the 4th metacarpal of a Rhino, although Elephant is still a contender – I will try to find some comparative material to confirm.

A massive ‘thank you’ to everyone who contributed ideas – it’s great to have some fresh perspectives and new directions to explore when you’re stumped!

Friday mystery object #247

This week I have a complete mystery for you to identify. I’ve checked this specimen against all sorts of species and have drawn a blank. So, I’m opening it up to you, to see if you have some inspiration to help me solve what this is:

mystery247

As usual, you can put your thoughts, questions and suggestions in the comments box below. I look forward to hearing your ideas!

Friday mystery object #246 answer

Last week I gave you this mystery skull from the stunning Galerie d’anatomie comparée et de Paléontologie in Paris:

mystery246

I was struck by the cat-like dentition and general shape, but as many of you worked out, that’s no cat.

It is in fact a specimen of a Fossa Cryptoprocta ferox Bennett, 1833, as correctly identified by Charne, Manabu Sakamoto, Nigel Monaghan, SMerjeevski – good skills!

Fossa by Ran Kirlian

Fossa by Ran Kirlian

This carnivore is endemic to Madagascar and is the foremost natural predator of lemurs. They are well adapted to climbing in order to catch their tree-dwelling main course, with rotating ankles a bit like a Margay.

Madagascar is an amazing place for biology. It separated from Africa around 20 million years ago and has had its own unique wildlife evolving there ever since. This means that the familiar cats that fill niches in (relatively) nearby Africa are missing, since they didn’t really exist when Madagascar started drifting off. The Fossa fills that catty niche.

There may be more mystery objects to come from the  Galerie d’anatomie comparée et de Paléontologie, since the whole place blew me away!

Wow