Friday mystery object #320

I hope everyone had a lovely Christmas break!

This week I have another specimen from the Dead Zoo to identify – this one has an identification already, but the taxonomy is rather archaic and I think that once you’ve investigated the modern version of the name, you’ll realise that it’s wrong.

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Skull length = 121mm

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So, any idea what this name should actually be and, more importantly, what the identification actually is?

As always, you can put your thoughts, questions and suggestions in the comments box below – have fun!

Friday mystery object #319 answer

Last week I gave you this unidentified skull from the Dead Zoo to have a go at identifying:

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It seems that everyone recognised this as the skull of a gull straightaway – the scars from the salt-glands on the top of the head and the shape of the bill combined to make it a bit of a give-away.

However, working out which species of gull is a bit more tricky, since many are remarkably similar in morphology, making size an important factor for consideration (I’ve talked about this before).

Now size is always a somewhat tricky thing to use for identification, for a variety of reasons. One is that there may be an overlap in size between species, another is that there will often be sexual dimorphism within a species that means you can’t just compare the length against another specimen of a species without considering sex. Then of course there’s age – if it’s not fully grown, it’s going to be smaller. Of course you also have to consider whether the bill sheath is present or absent, as this will add a few millimetres.

On top of all these issues, there’s the problem of how you actually measure the length in the first place. This is something I’ve researched in the past (link to pdf) and it’s a more significant problem than you might think. For example, when looking at the image I originally provided for the mystery object, it looks like the skull measures around 125mm, but if I chop the scale bar from the image, reduce the transparency to 50% and lay it directly over the centreline of the image of the specimen, it turns out to be around 128mm.

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Length is apparently 128mm

Add to this the fact that in the original image you can see a shadow under the scale bar, it becomes clear that the scale is somewhat elevated. This is because I raise the scale to be near the vertical midline of the specimen, to help keep everything in focus and limit the effect of parallax error. Normally this is good, because it allows a more accurate estimation of the length of a 3D specimen with a longest axis near the vertical midline, but in this case the longest part of the specimen is actually at the lowest part of the skull, so the elevated scale will make it look slightly shorter than it really is (due to the parallax error I was hoping to avoid…). This means that the specimen is probably closer to 129mm or 130mm in length.

With this in mind, the discussion about the lengths of various gull skulls between Wouter van Gestle (of Skullsite fame), Ric, Tim Dixon, Richard Lawrence, Gerard van den Brink and jennifermacaire needs to be reconsidered.

Richard Lawrence reported skull lengths for a variety of gulls as follows:

6x GBBG: 129 to 141 mm
2x LBBG: 117 mm
6x HG: 111 to 117mm
9x YLG: 111 to 126 mm ( larger with beak sheath though so would be smaller without).

So factoring in a length of 129-130mm for the mystery object it seems to fit well into the range for the Great Black-backed Gull Larus marinus Linnaeus, 1758. So well done to everyone who went for GBBG – this does seem most likely to be a skull from the largest gull species.

Great Black-backed Gull by Andreas Trepte, 2010

Great Black-backed Gull by Andreas Trepte, 2010

Friday mystery object #316

Back to bones this week, with a mystery skull for you to identify. Any idea what species this skull belonged to?

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I don’t think it will prove too much of a challenge for the bone geeks among you, so please try to be a bit cryptic with your answers to keep it fresh and fun for those who are not so familiar – and that’s a cryptic clue about what it’s not right there 🙂

Have fun!

Friday mystery object #314 answer(ish)

Last week I gave you this guest mystery object, courtesy of Joseph van Sambeek:

Mystery object. Image by Joseph van Sambeek, January 2000

The bony struts reinforcing thin plates of bone show it’s from something that lives in water all the time and which lacks lungs – you can tell this because this structure is what you get when you’re dealing with forces moving in a variety of directions, rather than mainly dealing with the constant force of gravity or compensating for buoyancy that is unavoidable when you live in water, but have lungs.

This means that many of you recognised it as being the neurocranium (that’s the bit of the skull that surrounds the brain) from a fish – more specifically from Sarah Gibson:

The first image is the skull roof, showing the elongated frontals and parietals (front of snout is left in first three images). Second image is a left lateral view, showing the internal parasphenoid that would pass between the two eye sockets. Third image is a ventral view, showing the bottom of the parasphenoid. And obviously last image is posterior view, showing the foramen magnum where the spinal cord would pass through, over the occipital condyle. It just may not look like a skull to some because it’s missing the eye sclera bones, jaws, cheek bones, pretty much anything that is not the skull roof or braincase.

However, as we all know, there are a LOT of different sorts of fish – around 33,600 described species and counting. This can make fish a nightmare to identify. However, there are some great resources out there, like Osteobase which has a very useful identification guide for various elements of a range of fish.

Alas, Osteobase didn’t have anything that fits this mystery specimen, so narrowing down to a species is rather difficult. I had the advantage of knowing that the specimen was collected in Baja California, although that was of little help in trying to get in an approximate area of the fishy family tree based on morphology, and there are still a ridiculous number of fish species is the area.

Sarah Gibson suggested that it may be a Barracuda, and it certainly fits in many aspects, but the shape of the frontals and parietals and details of the point of connection between the parasphenoid (that’s the bottom bar bit you see in the side view) don’t quite fit.

I had almost given up hope, when it occurred to me to concentrate on understanding the unusually large occipital condyle that Allen Hazen noticed, which suggested that it might be a taxon with an extremely extended rostrum (like the paddlefish or swordfish that Jennifer Macaire suggested) but with a weedier body and defined neck region since there would be no need for such a large articulation in a fusiform fish (they’re the muscular type that taper at both ends and have no neck, so don’t move their heads).

With this bizarre sounding fish in mind I was able to fairly rapidly narrow down the possibilities to one of the three species of cornetfish that live in the Pacific. I was delighted to find some great images of the skull of a Red Cornetfish, which matches the morphology very well.

Red Cornetfish Fistularia petimba from the Gulf of Mexico. Image by SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/NMFS/SEFSC

Red Cornetfish Fistularia petimba from the Gulf of Mexico. Image by SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/NMFS/SEFSC

However, the Red Cornetfish doesn’t really occur in the eastern Pacific, so it’s very unlikely to be that species. The Reef Cornetfish does occur in the eastern Pacific, but has only been reported in Californian coastal waters since November 2015 and this mystery specimen was collected back in January 2000 (which doesn’t make it impossible to be a Reef Cornetfish, just very unlikely). Which leaves us with the most likely identification (although by no means confirmed) of Deepwater Cornetfish Fistularia corneta Gilbert & Starks, 1904.

These long, thin fish can reach up to 2m, but they have tiny mouths that limit them to eating crustaceans, marine worms and smaller fish that they pick up from near the surface of reefs and the sea bed – presumably being harder to spot as a predator thanks to their very small frontal projected area.

I’ve asked Joe to check his specimen against the images of the cornetfish, since there’s nothing better than having a specimen in your hand when attempting an identification.

I hope you enjoyed the challenge!

Friday mystery object #306 answer

Last week I gave you this interesting skull to identify:

Specimen LDUCZ-Z1058 from the Grant Museum of Zoology

Specimen LDUCZ-Z1058 from the Grant Museum of Zoology

I didn’t mention that top of the cranium had been removed, probably as part of a postmortem, which is quite common for zoo specimens. Of course, this made the identification a bit more tricky.

That absent skullcap led to several suggestions of Tasmanian Devil, since they do have a very similar looking facial region to this specimen, with a short and blunt muzzle, robust zygomatic arch and even the same toothcount in the upper jaw. However, the Devils have an angular process of the mandible that projects medially (towards the midline) rather than backwards in a hook, so you wouldn’t see it in a side view.

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The correct answer was first tenuously suggested by palfreyman1414 in a pleasingly cryptic manner:

I’d have sworn this was a commie go-between for Cressida and Troilus

Which hints at “Red” and “Pandarus” giving us the Red Panda Ailurus fulgens F. Cuvier, 1825.

Red Panda image by Mathias Appel, 2016

Red Panda image by Mathias Appel, 2016

These charismatic critters are another example of an arboreal carnivore that is adapted to feed on a highly vegetarian diet, but unlike the previous mystery object (a Kinkajou) these cuddlesome floofballs eat mainly bamboo rather than fruit – rather like their very distant relative the Giant Panda (despite the similarity in diet and common name, the Red Panda is actually more closely related to the Kinkajou than it is the Giant Panda).

Red Pandas are a bit less highly specialised for feeding on bamboo than the Giant Pandas, probably because they have a more varied diet that also includes fruit, eggs, birds and small mammals. The poor nutritional quality of bamboo does mean that they spend a lot of time sleeping and they tend to move fairly slowly in order to conserve energy, although they can be very playful, especially in captivity where they can access higher quality foods.

Sadly, this playfulness and supreme floofyness is a bit of a problem for the wild Red Panda population. There is demand for wild caught Red Pandas in the pet trade and they are hunted for their thick fur right across their range through the foothills of the Himalayas, despite being protected by legislation in every country.

Friday mystery object #305 answer

Last week I gave you this specimen to identify, with a clue about the tail being distinctive:

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There were lots of correct answers – the first coming from palfreyman1414 who nailed it with this great cryptic clue relating to its scientific name:

Trump assortment pack

It is indeed Potus flavus (Schreber, 1774) or as Allen Hazen and jennifermacaire hinted at with kinky clues, a Kinkajou. They’re also known as Sun Bears, Lirón (which is also the Spanish name for the Dormouse) or Micoleón (lion monkeys).

A Kinkajou at the Paradise Animal Rehabilitation Center, Volcancito, Panama. Image by Dick Culbert, 2008

A Kinkajou at the Paradise Animal Rehabilitation Center, Volcancito, Panama. Image by Dick Culbert, 2008

As the name Micoleón suggests, these South American floofsters are what happens when a carnivore tries to be a monkey. They have dexterous digits for climbing and handling the fruit that makes up the bulk of their diet and they are one of only two carnivores with a prehensile tail (the other is the Binturong) – hence that tail clue.

This tail acts like a fifth limb that helps the Kinkajou climb and in particular it allows the animal to hang down in order to reach fruit at the ends of slender branches:

Kinkajou hanging using its prehensile tail. Image by Damian Manda, 2009

Kinkajou hanging using its prehensile tail. Image by Damian Manda, 2009

Unlike monkeys, the Kinkajou is nocturnal, relying on its sense of smell and touch more than its eyesight to work out which fruit is ripe. It uses its very long tongue to scoop out fruit pulp and sometimes to feed on nectar from flowers.

All in all it’s a very curious little carnivore that looks more like a lemur than it does its closest cousin, the Coatimundis.

Friday mystery object #305

This Friday I’m giving you a game of heads or tails from the Collections Resource Centre of the Dead Zoo:

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I don’t normally add a photo of the tail, but in this case it should make the identification a doddle – literally a 50:50 shot at getting the right species. If you know what I’m talking about, then please be cryptic in your suggestions – don’t spoil it for everyone else!

If you don’t know why this tail is so significant then you should know that the skull is 10cm long and all will be revealed next Friday!

Good luck!

 

Friday mystery object #300 answer

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

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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:

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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?

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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:

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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).

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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:

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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:

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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?

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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!

Friday mystery object #284 answer

Last week I gave you this part of a skull to have a go at identifying:

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It’s quite a distinctive structure and very particular to one particular group of mammals. It is of course an external auditory meatus (or ear hole as it’s more commonly known), but instead of opening directly into the auditory bulla (the inflated bony bulb that holds the ear bones) it has a long and robust tube.

Lee Post, Daniel Calleri & Dan Jones and Allen Hazen recognised this characteristic feature as belonging to a Beaver and Richard Lawrence went one better and narrowed it down to Castor canadensis Kuhl, 1820 – an identification that I agree with having seen the whole skull:

beaver_skull

I’m not sure if there’s any real functional reason for the ear tube, but it looks to me like it might be a “spandrel” a feature that’s an artefact of another adaptive feature – in this case the articulation of the mandible.

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Gnawing through a tree trunk is no easy task, so it’s not surprising that the Beaver has some serious adaptations to deal with the work involved. Unlike carnivores, which have a fixed lateral mandibular articulation powered mainly by the temporalis muscles, rodents have a dorso-ventral articulation usually powered by the masseter muscles, which allows the jaw to move backward and forward. In the Beaver the sagittal crest suggests that the temporal muscles are more involved than usual which, with the orientation of the articulation, may necessitate the ear tubes as lateral braces against which the mandible can secondarily articulate. That’s my guess…

Great work on identifying this specimen using very limited information!

Friday mystery object #283 answer

Last week I gave you this zoomed in picture of a specimen to have a go at identifying:

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It was a bit tricky, so I also gave you this bonus clue to help:

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I was impressed to see that, despite the limited information available from the images provided, many of you managed to work out that this shows the lightweight ‘honeycomb’ structure that supports the casque of a hornbill.

That was the first challenge but, as ever, I was keen to see if you could get the identification to species – far more of a challenge considering the lack of a side view of the skull and lack of a scale. To make up for that I’ve decided to provide the necessary image here:

Ceratogymna atrata skull

I won’t say what species this is in this post, as I normally would, just to give some more of you a chance to make the identification yourself. However, what I will say is that the very first response by Wood contained a link to an image of the correct species and later to a blogpost featuring this very specimen. In that post there is a discussion about the appearance of the casque, with speculation about whether it had been damaged during preparation, resulting in its appearance. However, as Richard Lawrence pointed out, this appearance is actually normal for the skulls of several species of hornbill.

I will also say that the discussion between Daniel Calleri & Dan Jones and Richard Lawrence about whether it was a hornbill from a genus starting with A or B was interesting and I initially thought it was an A, but am now convinced that it’s a C.

If you’re desperate to know which species it’s from, here’s a link to the skullsite.com page about it.

 

Friday mystery object #281 answer

Last week I asked for your opinion on this mystery object:

mystery281

It had originally been identified as Boa constrictor and then reidentified as Green Anaconda, but I didn’t believe either of those options.

There was some activity in the comments, from the initial observation that it’s a snake from Wood, to Andy Mills’ suggestion of Python, with palfreyman1414 and Daniel Jones and Daniel Calleri’s discussing how to tell whether it’s a boid or pythonid.

In fact, palfreyman1414 did some sterling work tracking down characteristics to help distinguish between these commonly confused groups, with this handy comment:

“The postfrontal bone, usually present, borders the orbit behind, rarely also above, and in the pythons a supraorbital bone is intercalated between it and the prefrontal bone.”

And..

“Boids are, however, distinguished from the pythons in that none has postfrontal bones or premaxillary teeth”

The character of the presence or absence of teeth in the premaxilla (the frontmost bone of the upper jaw in the midline of the skull) is particularly useful, although it’s not unusual for the premaxilla to fall out of snake skulls.

The postfrontal character is a bit less obvious and I’m not fully convinced by it – not because there isn’t an extra bone in the pythons compared to the boas (there is), it’s just whether it’s a postfrontal, a supraorbital or a post orbital. That depends on the reference you read. To help get an idea of the bits we’re talking about, I’ve highlighted them here (purple for premaxilla, pink for the bit missing in boids, call them what you like):

mystery281_bones

It’s probably worth mentioning that Anacondas are members of the boid family, so it’s clear that this specimen is a pythonid rather than a boid. But that doesn’t tell us what species it is (if you want to see a Boa constrictor skull there’s a video of one here).

Comparing overall skull shapes in snakes is not very effective, since the skull is very loosely articulated to allow it to deform when swallowing large prey, so when mounted they can be very variable in shape. Because of this you need to compare the shapes of the various bones that make up the skull to narrow it down.

There is a very helpful image resource called BioLib that has validated photos of skulls amongst other images, so it’s well worth checking out. Trawling through I didn’t manage to find a species with the same shapes in the nasals, prefrontals, frontals, parietals and supratemporal – but I did discover a specimen photo by Jean-Christophe Thiel that fit (not to mention a previous mystery object) – so I’m fairly confident that this is a Royal Python Python regius (Shaw, 1802).

Many thanks to everyone for their comments – it’s been a fun challenge where I know I’ve learned an awful lot. I hope you have too!