Friday mystery object #413

This week I’ve been packing some of the Dead Zoo’s beautiful Blaschka glass models, that were moved during our decant and have been sitting in my office waiting to be dealt with:

Most of the Blaschka models we have are well identified and many even have the number that they were given for ordering in the Catalogue of Glass Models of Invertebrate Animals, Ward’s Natural Science Establishment, by H. A. Ward, Rochester, N.Y., 1878.

However, as is sometimes the case with old collections, there has been a degree of dissociation of information from the specimens and one or two of our models have lost their data. This little squid is one such specimen.

I managed to track down the modern accepted name for this specimen, which is very different to the name used by the Blaschka’s when they made and sold this model. With that original name I was even able to figure out the order number from the Ward catalogue. I enjoyed the detective work and I hope you do too!

Let’s see if you all come to the same conclusion about this specimen as I did. I’ve added a couple of extra images below to help you in your quest. Have fun!

Friday mystery object #412 answer

Last week I gave you this rather nice skull to identify:

I was hoping that it would catch some of you out, since at first glance it looks like the skull of some kind of canid. I thought I had caught out Joe Vans, but then he noticed one of the features that sets this skull apart from dog skulls – the pinched-in section in the mid-muzzle area. Then everyone started piling in with their observations and my hopes of being tricksy were fully dashed.

This is of course the skull of that paragon of convergent evolution, the Thylacine (AKA the Tasmanian Wolf or Tiger) Thylacinus cynocephalus (Harris, 1808).

I’ve written fairly extensively about convergent evolution between Thylacines and canids before, when I worked at the Grant Museum of Zoology, so I won’t go into huge detail here, but I will give you an annotated image showing some of the features to look for that help distinguish these marsupial carnivores from their placental dopplegangers:

A= 8 incisors vs 6 in canids
B= Lacrimal duct on outside of orbit
C= Inwardly deflected angular process
D= “Pinched” midsection of rostrum
E= Palatal vacuities

These physical differences between the Thylacine and the Eutherian canids are features common to many marsupials and they act as reminders that evolution is limited by what it has to work with. At the most fundamental level that means DNA.

In recent years the methods for successfully extracting and sequencing DNA from museum specimens has moved on in leaps and bounds. In 2018 these advances allowed the Thylacine’s genome to be assembled, allowing comparison with their morphologically similar, but taxonomically distant counterparts.

The team that did this went looking for similarities between protein coding genes in the different lineages at first, to understand what was driving the morphological convergence – but it seems that they were looking in the wrong place.

When they looked more closely, it was actually in the cis-regulatory elements (the non-coding DNA that used to be considered “junk”, but which is now recognised as playing a vital role in regulating development) that genetic convergence was seen. It turns out that these elements were also driving convergence in brain development between Thylacines and canids.

It seems that protein coding genes are quite stable – if they mutate they usually stop working properly, so the mutation often doesn’t persist. But mutations in cis-regulatory elements can change gene expression with less risk of catastrophic consequences. Unsurprisingly that means they are increasingly being seen as the main drivers in evolutionary adaptation. If you’re interested in finding out more about this fascinating research, a pdf of the 2019 paper on Thylacine/canid genetic convergence by Feigin, Newton & Pask can be accessed here.

I hope you enjoyed this short trip down the road of convergent evolution, with a hat-tip to the genetic drivers involved.

Friday mystery object #412

After last week’s foray into insects, I have a nice chunky vertebrate skull to for you to have a go at identifying:

Any idea what this might be from? I have a feeling this may be way too easy for some of you, so let’s keep the answers cryptic or perhaps poetic, so everyone gets a chance to figure it out for themselves. Have fun!

Friday mystery object #411 answer

Last week I gave you this (somewhat dusty) mystery object to try your hand at identifying:

I know that insects aren’t a frequent occurence on the blog, so this was a bit of an unfamiliar one for many of the regular Zygoma commenters. Of course, that didn’t prevent some astute observations.

Chris Jarvis immediately spotted that this is a wood wasp or sawfly, while palfreyman1414 flagged that it looks more like a fly (barring the long ovipositor). That’s because wood wasps, despite being members of the Hymenoptera, lack that characteristic wasp-waist that makes the Apocrita (the hymenopteran Suborder containing wasps, bees and ants) so distinctive.

Not a fly, but not really a wasp either

The Symphyta is the Suborder containing the sawflies and there are thousands of different species. However, narrowing it down wasn’t really that hard, since sawflies specialise in using their ovipositor to lay eggs in the stem of quite specific host plants and the only sawflies in this size range are in the family Siricidae, which are the ones that pick on trees (which is pretty interesting, since they form a symbiotic relationship with wood-digesting fungi in order to feed on wood as larvae).

Quite a big bug*

Of course, being insects, there are still around 150 to choose from, but between ruling out taxa that have adopted Batesian mimicry and those that are a very different size or shape, it becomes easier to narrow down the possible contenders – especially when you consider that this one turned up in Dublin, Ireland (although as pests of wood they can emerge from pine timbers a long way away from their point of origin – this one probably got into the Dead Zoo in some of the timber being used for our big decant project). The best fit for this specimen lies in the Genus Sirex.

When tryingto to distinguish between members of Sirex it’s important to pay attention to colour details of the legs and antennae. In this case it has red legs and black-and-red antennae. If you spend a while checking through the very helpful Sawfly GenUS resource you’ll find that the best fit for the mystery specimen is a female Sirex juvencus (Linnaeus, 1758).

Of course, the entomologists out there managed to figure all this out without any problems, both on Twitter and in the comments.

So well done to Jaswinder and Russell Stebbings for getting a species level identification – I would say that you got it right, but since I’m not an entomologist I think I should just be pleased that your more informed opinions happen to support my best guess. Thanks!

Stay tuned for another mystery object next Friday. Have a great weekend everybody!

*not a Bug – the True Bugs are Hemiptera and have nothing to do with this.

Friday mystery object #410 answer

Last week I gave you this rather fishy skull to have a go at identifying:

There was a lot of discussion about what it could be, which is unsurprising, since there are a LOT of fish species – with over 34,000 possibilities. This one proved additionally confusing, since it seems to have no teeth, as mentioned in the comments by Adam Yates. Fortunately, Wouter van Gestel flagged that some species with several rows of teeth tend to lose those teeth during preparation if it’s not done with sufficient care, which is useful to know.

I picked this object because I get a lot of requests for identifications of fish skull bones and this specimen is helpful, as it has the various bones of the skull labelled individually:

This specimen also happens to be a fish from a family that often comes up for identification. The neurocranium (or braincase) has a fairly characteristic shape in these fish, which is best seen from above on the skull (although unfortunately it’s not labelled in the image below):

The neurocranium tends to be a bone that gets found on beaches quite commonly. In fact, I have had a similar neurocranium as a mystery object in the past, so you may have seen one here before:

This shape is what I expect to see from members of the True Cod family, the Gadidae. Clearly a lot of other people recognised this as well, since Chris kicked off the comments with references to Gadus, Cod and Pollock and there were lots of suggestions of Cod and Pollock (AKA Saithe) on Twitter:

Unfortunatley, this is where it gets more complicated. Differentiating between different Gadids isn’t always easy. The size suggests it will be one of the larger members of the family – Cod, Haddock or Pollock being the main focus. Haddock is easy enough to dismiss, since they have small mouths, with lower jaws (composed mainly of the dentary and articular bones) that don’t project as far as we see in this specimen.

After that it gets really quite tricky – to the point where I am now doubting the original identification we have for the mystery object. This specimen was labelled as an Atlantic Cod Gadus morhua, although the original identification when acquired from Rowland Ward was Pacific Cod Gadus macrocephalus. But after a lot of searching of images from some pretty reliable online resources, I’m increasingly convinced that the specimen is a Pollack, Pollock or Saithe Pollachius pollachius (Linnaeus, 1758) – N.B. I’m ruling out P. virens since the lower jaw proportions are wrong.

The reason I’m thinking Pollack is based around a few small features of a couple of the bones of the skull. In particular, I’m interested in the shape of the hyomandibular and the opercular (Osteobase has these elements for Cod, but unfortunatley not Pollack). To give you an idea of the differences, here are the Cod elements (superimposed in blue) alongside the same bones of the mystery object (tinted red):

These differences are consistent across the skull specimens of Cod and Pollack that I’ve managed to find. The Cod has notch in the upper leading edge of the hyomandibular, unlike the Pollack, which has a more obtuse smooth line along the leading edge. The Cod also has a notch in the trailing lower edge of the opercular, that is just seen as a slight concavity in the Pollack.

I’d be interested to hear what you think about these suggested features!

Friday mystery object #409 answer

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

Everyone spotted that this is the skull of a toothed whale (or large dolphin), but after that, things got a little bit more confusing. In particular, the arrangement of the four pairs of teeth in only the front section of the lower jaw, seems to have thrown a lot people off.

There were several suggestions of Beluga whale, but they have around 40 teeth between the upper and lower jaws and clearly this doesn’t (and even if teeth had fallen out, you’d expect to see some empty sockets in the mandible). There were also suggestions of Narwhal, but they have a maximum of 4 teeth only in the upper jaw and one – or very occasionally two – form the Narwhal’s unmistakeable tusk(s). This is neither a Beluga whale nor a Narwhal.

However, the similarity of this skull to these two species did lead to speculation about whether this might be a hybrid between Beluga and Narwhal – one of the infamous Narlugas (or more accurately Belwhals). Ed Yong wrote about these real, but very rare, animals in the Atlantic a couple of years ago and I recommend having a read. If you do, you’ll discover that only one specimen is known and this is most definitely not it. As disappointing as this will no doubt be for some, we live in a world where hopes and dreams are routinely dashed against the rocks of reality, so let’s get ready to rock.

There are around 30 species of Oceanic dolphin, ranging in size from 50kg to 10,000kg. You can see that this one is a bit bigger than the specimen next to it and it has much broader and more chunky ‘cheeks’ (for want of a better term). This is something I normaly associate with the bigger dolphins that are usually referred to as whales – things like Pilot whales, Killer whales and the species in the Monodontidae that I mentioned earlier.

Most of the Delphinoidea have a lot of teeth to assist with prey capture, but this mystery object has got creative with just 4 pairs in the lower jaw (although obviously not as creative as the Narwhal). This limits the possibilities significantly, since it’s a fairly unusual condition. The other type of whales that only have a small number of teeth in just the lower jaw are the beaked whales, which primarily feed on soft-bodied cephalopods and have repurposed their teeth for competition. The mystery species has, perhaps unsurprisingly, done the very same. So, we’re left with the question of which of the bigger dolphins feeds on cephalopods and has an unusual arrangement of teeth?

The answer, as Adam Yates was the first to share, is the Grampus or Risso’s Dolphin Grampus griseus (G. Cuvier, 1812). They have between 7 and 2 pairs of teeth in their lower jaw and none in the upper. The live animals are quite heavily scarred from their interactions with those teeth.

Grampus illustration by Citron / CC-BY-SA-3.0

Stay tuned for another mystery object next week!

Friday mystery object #408 answer

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

Obviously the horns let us know that it’s some kind of bovid, but as has been noted before, there are a LOT of bovids. Overall horn configuration is a useful indicator of which general part of the bovid family tree to consider and I always find myself needing to check references to make sure I remember the general configurations.

A very helpful overview of horn morphology for the main subfamilies within the Bovide is illustrated by M. Van Bolt in a paper by Barbara Lundrigan from 1996*

Horn morphology in the main subfamilies within the Bovide. Illustrated by M. Van Bolt in Lundrigan, 1996*

Capturing the horn angle accurately in a photograph can be quite tricky, which is why I provided more than one angle:

A quick check shows that the horn shape of this specimen is distinctively Reedbuck. There are three species in the Genus Redunca, with fairly clear differences in things like the proportions of the maxilla and the shape of the orbit, but again the horns offer a clue.

Mountain Reedbucks have short horns, only in the region of about 15cm, a bit on the short side for this specimen, where they look to be around 25cm or so. The Southern Reedbuck has much longer horns in the range of 35-45cm, a bit bigger than this specimen. That leaves one Goldilocks species with horns 25-35cm long – the Bohor Reedbuck Redunca redunca (Pallas, 1767).

So well done to everyone who recognised this as a Reedbuck and special props to Goatlips who suggested Bohor Reedbuck. Hopefully the illustrated phylogeny I shared will help with future identifications.

*Journal of Mammalogy, 77(2):462-475, 1996

Friday mystery object #407 answer

Last week I finally got a chance to share a nice skull from the Dead Zoo for you to identify:

Bird skulls are always an interesting challenge, because the bill can give away some useful clues and there is a fantastic online resource available to help with their identification, in the form of SkullSite, run by Zygoma regular Wouter van Gestel. Perhaps unsurprisingly Wouter tends to be one of the first to get a correct answer when the mystery object is avian – and this one was no exception.

One of the useful features on SkullSite is the ability to do a custom search, which allows you to restrict the size range of skulls and the bill shapes to search through. This allows easy comparison between the skulls of possible taxa, making identification more straightforward, once you get your eye trained to recognise useful features.

In this case there are a few species in the same size range with similar shaped bills. The closest species in size and shape (that’s not a close relative) is the Great Bustard. However, the Great Bustard has much longer nares (the fancy name for nose-holes) than the mystery object and the bustard’s lacrimal bones (the small bones that flare out just to the front of, and above, the eye sockets) are much smaller and less pronounced than what we see in the mystery specimen.

That leaves the two species in the Family Cariamidae (or Seriemas) to pick from. The size of the specimen alone makes that fairly straightforward, as there’s around 15mm difference in the skull length between the two. However, if you want a morphological feature, the mandibular fenestra (the ‘window’ visible in the side of the lower jaw slightly back from the midway point) is proprtionally a lot larger in the Black-legged Seriema compared to that of the Red-legged Seriema.

The fenestra is small in the mystery object, while the skull is large, making this a specimen of the Red-legged Seriema Cariama cristata (Linnaeus, 1766).

A Red-legged Seriema in Reserva Ambiental, Piraju, São Paulo, Brazil. Image by Dario Sanches, 2010

I tend to think of Seriemas as the South American equivalent of the Secretarybird, since they are ground-hunting predators in scrubby environments that have a fondness for venomous snake snacks.

Both have long legs and small feet, neither fly much and both have eyelashes, as pointed out by Goatlips on Twitter:

I’d never really consider the bird eyelashes thing and it makes perfect sense for terrestrial birds foraging on the ground in arid environments to have some extra eye protection from sun and dust afforded by filamentous feathers around the eyes. It turns out this holds true for birds like Ostriches, Emus, Cassowarys, Rheas, Road-runners and the Ground Hornbills.

However, some other Hornbills that live in very different environments also have eyelashes as do those odd arboreal Hoatzins, so there must be something else going on with those lovely lashes that I’m missing.

I hope you enjoyed this bony challenge – please feel free to add your thoughts on the eyelash situation and perhaps mention any species you’ve noticed this feature in before. You never know, together we might figure out what those lashes are all about.

Friday mystery object #406 answer

Last week I gave you this mystery object from the Dead Zoo:

Usually I don’t give you clues, but for this one I thought it might be helpful in narrowing down possibilities since this specimen is faded and is probably lacking a lot of the colour features that might help with an identification. The clue wasn’t hugely helpful however, just a reference to the collector – one Major St. Leger Moore.

Palfreyman1414 and salliereynolds made the inital observation that this is an ungulate, but there are very many ungulates and that doesn’t narrow it down by much. Goatlips went on a bit of an adventure with Major St. Leger Moore and found some useful information – the Major served in the 9th Lancers who were posted to India during his service, in which time he picked up polo (which he was apparently involved in appropriating for Britain) and most likely this particular trophy.

With this information it becomes a bit easier to start narrowing down likely possibilities – there are around 21 species of bovid in India and only one of them looks anything like this – the Chinkara or Indian Gazelle Gazella bennettii (Sykes, 1831), which Goatlips hinted at with a cryptic reference to a cricketer. Of course, there are plenty of gazelle species in Africa, which Major St. Leger Moore may have visited outside his time in the military, since he was a keen sportsman and recognised as being able to “shoot straight”.

Checking the features of the Chinkara helps to add confidence to the identification. According to the ADW the Chinkara is:

…characterized by a sandy, yellowish and red colored fur with a pale white ventral region. Facial markings are well developed: they have a dark brown or black forehead and a light face with dark stripes and a noticeable nose spot. Fur color varies seasonally. In the winter, Indian gazelles are a dark grayish sandy color, and there is a distinct brown band edging the white ventral area of the torso. In the summer, the fur is a darker brown.

Indian gazelles have straight horns with prominent rings and tips that are slightly out-turned. Horns are found on both males and females, although they are relatively shorter in females. Sub-adult males are hard to distinguish from females because of their intermediate horn length. Horns can reach lengths of 250 to 350 mm in adult males. Female horns are usually half the length of and thinner in width than male horns and have less prominent rings. Average male horn length of the subspecies Gazella bennetti fuscifrons and G. b. shakari is 256.6 mm. Females of these subspecies have an average horn length of 184.7 mm.

McCart, D. 2012. “Gazella bennettii” (On-line), Animal Diversity Web. Accessed April 22, 2021 at https://animaldiversity.org/accounts/Gazella_bennettii/

While the colours preserved on the specimen aren’t quite good enough to provide much assurance, the details of the horns (especially when compared to other gazelle species, that often have much longer and more lyrate horns) correspond very well with the Chinkara. Not a certain identification, but pretty convincing.

So well done to Goatlips for some nice detective work!

Friday mystery object #406

Happy Friday everybody! This week I have a genuine mystery object to solve from the Dead Zoo:

This specimen has no location information and only a generic name associated with it – the only other information is that it was collected by Major St. Leger Moore. That might help. Or it might not. Let’s see what you manage to come up with!

Friday mystery object #405 answer

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

There was no scale and admittedly there’s not much of the specimen visible, but I didn’t think that would pose much of a problem. And I was right. Tony Irwin immediately indicated the identity of this rather rare specimen with the anagram:

Maybe found it – in rosy pea?

The “in rosy pea” unscrambles to Aepyornis which is the generic name for the Elephant Bird.

Of course, this isn’t a complete Elephant Bird, it’s only an egg (had to get some Eastery link in there somehow). Elephant Birds have been extinct for about 1,000 years, so surviving eggs are very rare, hence the special fancy box. Here’s the actual egg:

The total length is just shy of 1 foot at 29.6cm, making this one of the largest eggs ever laid by any animal. There are other Elephant Bird eggs that are a bit bigger (up to 34cm), but no other type of animal ever laid a bigger egg, even the vast sauropod dinosaurs laid eggs that were smaller than this.

I’m not going to tell the story of this specimen here, since it’s already on the National Museum of Ireland’s website. If you have a read of that, you’ll see that this specimen is from the southern end of Madagascar (the island on which these birds lived) and that plus the particularly large egg size suggests that this is from Aepyornis maximus I. Geoffroy Saint-Hilaire 1851.

This is not the first time I’ve dealt with Elephant Bird eggs, since I borrowed one from David Attenborough for an exhibition at the Horniman Museum about 5 years ago, which I talked about here.They are remarkable objects and it’s strange to think of something as fragile and seemingly ephemeral as an egg surviving intact for over a thousand years.

So well done to everyone who worked out what this mystery was – eggcelent work!

Friday mystery object #404 answer

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

It wasn’t really much of a challenge for the usual suspects, with everyone recognising this as a Common Hill Myna Gracula religiosa Linnaeus, 1758.

However, my reason for picking this as a mystery object wasn’t for the challenge offered, but as an illustration of just how frustrating the taxonomy of old collections can be. Everyone recognised this bird, which is not a huge surprise, given how familiar this species has become due to the pet trade, but anyone looking at this specimen on display would probably struggle to match the specimen to the species considering the label that was attached:

The common name here suggests that the specimen is from Malaysia, then the scientific name suggests Java, but then the locality associated is just “East Indies”. The genus name does at least bear a passing relationship to the modern specific name (“Eulabes” means “pious” or “devout” while “religiosa” is self-explanatory). Similarly “Grackle” does hold a clue to the modern Genus name of “Graculus“. Most confusing.

To make things worse, the Graculus is now recognised as forming a species complex across Asia, so it would be good to narrow down which subspecies this specimen belongs to:

Distribution of the various species and subspecies within the genus Gracula. Image by L. Shyamal, 2009

The pattern of coloured feathers on the neck and head on the Dead Zoo specimen appears to match G. religiosa intermedia most closely, so when I eventually reach the stage of rewriting labels for specimens on display, I’ll do my best to improve the information. Unfortunately, this will probably need to happen for around 75-80% of the collection, so no pressure…

Friday mystery object #403 answer

Last week I gave you this rather beautiful mystery object from my old place of work, the Horniman Museum:

It’s the only example I’ve seen of this species that’s been prepared to show it from this perspective – and it’s pretty special. There were plenty of answers, with most people on the button with the what it’s from.

Goatlips was the first to jump in with the broader identification, but palfreyman1414 was first to get the the species. The highly reflective, pearly surface (comprised of mother-of-pearl or nacre) provides a bit of a clue. This is a transverse section of a Pearly or Chambered Nautilius Nautilus pompilius Linnaeus, 1758.

Normally when people take sections through a Nautilus they take a sagittal section, to show the near perfect logarithmic spiral formed by the shell as it grows, so the transverse section offers a perspective that’s much less familiar:

Image of Nautilus shell in sagittal section taken by Chris 73, 2004

Since the transverse section is so unusal it’s quite difficult to find good references for identification. However, with a good imagination you can work out what’s going on with the relative sizes of the chambers and how much they overlap, to get a sense of the shape in the coronal plane (that’s the line through the body that gives us a transverse section).

That said, it’s easy to recognise that this shell is from the genus Nautilus rather than Allonautilus thanks to this image from Jereb and Roper, 2005:

Shell characters of genus Nautilus vs. genus Allonautilus. After Jereb and Roper (2005), modified by Antonov, 2008

There is also a paper by Ward and Sanders, 1997 with the same sections shown, plus an additional illustration of N. macromphalus which lacks the thick side walls seen in N. pompilius. From what I’ve seen I’m reasonably happy that the specimen is a Pearly Nautilus, but the taxonomy of this ancient group of cephalopods is still quite poorly known, so I’ll hang on to a shred of doubt for a while.