Friday mystery object #318 answer

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

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It’s a fairly distinctive looking specimen with that massive bill, immediately narrowing down the possible families to two likely contenders – the Toucans (Ramphastidae) or the Hornbills (Bucerotidae).

On closer examination it lacks the serrated bill margins and remarkably long medial (in this case that means ‘towards the midline of the skull’) process of the quadrate bone (a part of the jaw in birds that I’ve blogged about before) that you see in Toucans. So, it’s a Hornbill – as everyone correctly spotted in the comments – but then we have the question of the species.

There are around 60 Hornbill species, with most of them sporting quite distinctive casques which make them quite identifiable (I’ve blogged about several before):

Ceratogymna atrata skull

Black Hornbill Ceratogymna atrata

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Great Hornbill Buceros bicornis

Bucorvus abyssinicus (Boddaert, 1783) sectioned skull

Northern Ground-hornbill Bucorvus abyssinicus

However, this specimen seems to be lacking a casque. This could be due to a few reasons. There are some casqueless species, such as the Sri Lanka Grey Hornbill, it could be a young female adult from a small casqued species with sexual dimorphism in casque development, or it could be a young juvenile from a species that has a small casque that grows as the animal matures.

Assuming it’s one of these, it’s easy to check the few casqueless species by looking at the overall bill shape, the position of the nares (nostrils) relative to the orbits (eye sockets) and checking the structure of the jugal and quadratojugal (the thin bones on the side of the skull under the orbit) – this last only if you can find a reliable skull image for comparison.

Using Skullsite and images on the internet it’s time-consuming, but straightforward to rule out a lot of possibilities, since most Hornbills have a fairly robust jugal/quadratojugal and nares located much further away from the orbit than you see in the mystery specimen. In fact the only Hornbills with a similar nares/orbit position and gracile (skinny) jugal/quadratojugal and in the right size range (that I was able to find) were in the genus Rhyticeros L. Reichenbach, 1849.

Unfortunately I’ve not found good skull images of juveniles for all of the species to make a final comparison and you can’t just compare the skull of a juvenile with an adult and expect to see the same configuration and development of features, as there’s still growth to happen (something else I’ve talked about before).

So based on the information it looks like jennifermacaire was the closest with her suggestion of Wreathed Hornbill, although I’m leaning slightly more towards the Papuan Hornbill Rhyticeros plicatus (J.R.Forster, 1781).

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Hope you enjoyed the challenge!

Friday mystery object #317 answer

Last week I gave you this unidentified bird skull from the Dead Zoo to try your hand at identifying:

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It seems that everyone recognised it as being from a charadriiform, and one of the waders at that. The first response was from Chris, who made reference to Lewis Carroll’s poem the Walrus and the Carpenter in which the eponymous characters eat an enormous quantity of oysters – hinting that this is an Oystercatcher.

There were some other suggestions that it could be from one of the birds in the genus Tringa, which includes the ‘shanks’ (Redshank, Greenshank, etc.), but the morphology fits one of the Oystercatchers better – in particular that weird constriction about halfway down the mandible when you look at the skull in profile.

This mandibular ‘waist’ is quite unusual and it doesn’t even seem to occur strongly in all of the Oystercatchers, which helps narrow down the likely species within the genus Haematopus, especially when you factor in things like the relative bill proportions, although you have to be careful doing this as there is some sexual dimorphism in the shape of the bill, with the females’ being longer.

The three closest species are the American Oystercatcher, the Sooty Oystercatcher and the Blackish Oystercatcher, but unfortunately I’ve not been able to find good reference skulls all of these species to be able to look for any distinguishing cranial characters. Based on bill morphology I’m leaning towards this being the skull of the American Oystercatcher, Haematopus palliatus Temminck, 1820.

American Oystercatcher by DonaldRMiller, 2010

American Oystercatcher by DonaldRMiller, 2010

My next step will be to check through our collections to see if we have comparative material to check the identification (once I get some time – a sadly rare commodity). If I can’t confirm I’ll just stick with Haematopus sp. on the label.

If you’re not familiar with Oystercatchers, they walk along the tideline either prying or breaking open bivalves. In my experience they seem more fond of mussels than oysters, but what do I know?

Another mystery next week!

Friday mystery object #317

For this week’s mystery object I’ve decided to stick with my favourite subject of skulls. This time it’s a bird from the Dead Zoo’s collection, that was in a drawer labelled “Unidentified” – let’s fix that!

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Any idea what species this skull belonged to? I have my suspicions, but I’d love to hear what you think.

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

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 #315 answer

Last week I gave you this big bug to identify:

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I had a feeling it would be fairly straightforward for some of you, since insects as big as this are reasonably distinctive, and I was therefore not disappointed with the flurry of correct identifications.

The first with a correct identification in the comments was Chris, who hinted at the scientific name with this suggestion:

Trying to identify this Cic-sac? Tho phar, Tho good! (Excuth the lithp!)

On social media people made suggestions relating to the common name for the species, mostly pointing out that it’s very loud. Putting the various hints together gives you the Double-drummer Cicada Thopha saccata (Fabricius, 1803).

Cicadas are weird. They’re in the Order Hemiptera (the true bugs) and the Suborder Homoptera (although that’s disputed and it’s probably safer to say Auchenorrhyncha). Best known for being noisy and having some species with synchronised emergence times that vary between every year and up to every 17 years, or somewhere in-between depending on species and environment. They have widely spaced eyes and a blunt head that is pretty distinctive.

As jennifermacaire pointed out regarding cicadas:

According to Plato, “[This species] used to be human beings who lived before the birth of the Muses. When the Muses were born and song was created for the first time, some of the people of that time were so overwhelmed with the pleasure of singing that they forgot to eat or drink; so they died without even realizing it. It is from them that the race of the [these insects] came into being; and, as a gift from the Muses, they have no need of nourishment once they are born. Instead, they immediately burst into song, without food or drink, until it is time for them to die. After they die, they go to the Muses and tell each one of them which mortals have honored her.”
– Phaedrus

The implications of this is that adult cicadas have a general inability to feed, although this isn’t quite true, since adult cicadas may still feed on sap.

This particular cicada is Australian and is one of the loudest insects on the planet, able to produce a call of over 120 decibels – loud enough to cause permanent hearing damage if right up against a human ear.

The abdomen is fairly hollow in the males of these insects, creating a resonating chamber, but sadly the last segment of this specimen has fallen off, making it hard to be sure of the gender on the basis of the genitals. However, the males have a couple of resonating sacs behind the hind-wing that is missing from this specimen, suggesting that it’s a female.

As far as noisy neighbours go, these insects are an occasional disruption, popping up every 4-6 years and making a noise that is apparently similar to high-pitched bagpipes.

It doesn’t sound great to me, so I’m (not so) secretly glad that I only have to deal with dead examples of these fascinating insects.

More mystery object fun next week!