Friday mystery object #346 answer

Last week I gave you this funky fossil from the National Museum of Ireland to have a go at identifying:

20181208_161002-01.jpeg

Everyone in the comments immediately recognised that this is the fossil of something that flies, thanks to the slender bones. The general consensus from the outset was that it was Archaeopteryx, but I wonder how much of that is because this specimen is preserved in the same Middle Jurassic lithographic limestone from Solnhofen that preserves the first bird?

The Berlin Archaeopteryx

The Berlin Archaeopteryx

However, Allen Hazen noticed the long slender finger that marks the mystery object as something different, when he correctly suggested that it was a pterosaur, winning over palfreyman1414 and sallie reynolds. On Twitter, @Robertgagliano1 went one better and got the correct genus when he suggested Germanodactylus.

This is indeed a fossil of Germanodactylus cristatus (Wiman, 1925). These small Jurassic pterosaurs were about the size of a raven and it is thought that they may have fed on marine crustaceans and molluscs, based on their fairly robust teeth.

This particular specimen is currently on display in our Jurassic Skies exhibition (that I talked about a fortnight ago), as it helps represent the successful group of flying reptiles that were already in the air 150 million years ago, when feathered dinosaurs first took to the skies.

In an unexpected twist, research was published just a week after we opened the exhibition, describing the first evidence for feathers in pterosaurs. This was unexpected, although fur-like filaments had already been recognised in the group. This means it’s possible that feathers originated in a common ancestor of dinosaurs and pterosaurs – which may have even included the group that is today represented by the crocodiles.

This means it’s possible that the ancestors of crocodiles would have been feathered and modern crocodiles have lost this covering, possibly thanks to their specialisation for living in water. I find it quite interesting that a reticence to add feathers to representations of dinosaurs (in things like Jurassic Park) has been influenced in part by the scaly skin of modern crocodiles (the nearest living relatives to dinosaurs that are not birds), but now we find out that crocodiles may have had feathers and lost them, making prehistory a much more fuzzy place than we ever dreamed!

Friday mystery object #345 answer

Last week I gave you this squee squamate to have a go at identifying:

As usual the comments were insightful and bang on target, with a correct identification by Chris, jennifermacaire, sallie reynolds and Allen Hazen. In the comments there was even a link to a very useful paper provided by jennifermacaire and a mention of the value of the tail-tip shape as a way of distinguishing between species of flying gecko.

Unfortunately the end of this specimen’s tail was hidden behind a label, so it wasn’t visible in any photos, but if it was it would show that this is a Common Flying Gecko Ptychozoon kuhli Stejneger, 1902. Distinctive tail-tips aside, the comments also picked up on some very interesting points about gliding replies. As Allen Hazen mentions:

… So gliding with a patagium along the side of the body (not supported by the arms and legs as it is in typical mammalian gliders) has evolved at least FOUR times in reptiles (reptilia sensu very lato): these guys, Draco, Kueneosaurus, and another fossil form I can’t remember the name of. …

Which is both interesting and pertinent to the main reason I picked this object, as it’s one of the specimens I selected for the temporary exhibition Jurassic Skies we just opened at the National Museum of Ireland at our Collins Barracks site, which is about the origins of flight in dinosaurs (i.e. birds).

This slideshow requires JavaScript.

Gliding lizards don’t have much to do with the origin of birds directly, but the high frequency with which they seem to pop up is a good indicator that there’s a clear benefit to being at least partially air-worthy.

Escaping predators, reaching inaccessible food and exploiting otherwise hard-to-reach habitats can all play a role in tempting animals into the air. The interesting thing that I’ve realised from doing this exhibition is that we’re currently in a bit of a dull patch when it comes to flying critters.

In the Jurassic the pterosaurs dominated the skies, with birds arising and finding a niche despite being newcomers to the aerial scene. By the Cretaceous both birds and pterosaurs were very diverse, with giant Quetzalocoatlus pterosaurs the size of a small plane and toothed and toothless birds living in a variety of habitats.

The K-T boundary mass extinction seems to have wiped out a huge amount of vertebrate diversity in the skies and despite the huge number of bird species alive today, the diversity of forms seems lower than it has in the past.

If you happen to be in Dublin before 24th March 2019 I suggest popping over to the Collins Barracks museum site to take a look at the exhibition. It’s free and it offers a chance to see some of our specimens that have never been on display before, plus a rather lovely new model of Archaeopteryx that we commissioned for the show.20181211_162925

Friday mystery object #344 answer

Last week I gave you this impressive insect to have a go at identifying:

mystery344.jpeg

No scale for this, but it’s probably safe to say it’s bigger than you’d be comfortable with.

By not giving the scale I was being a bit mean by holding back a useful clue. This fly (as recognised by palfreyman1414, Richard Blackmore and joe vans) is around 45mm long, making it one of the biggest of its kind – its kind being one of the Asilidae or robber flies.

The species is from Australia and it’s called the Giant Yellow Robber Fly Blepharotes coriarius (Wiedemann, 1830). They’re active hunters that prey on other insects, grabbing them in flight and carrying them off to a perch where they suck out their victim’s internal organs. Nice.

Apologies for the short answer this week – I’m just in the process of installing an exhibition and this specimen is one that is going on display to represent the Diptera. Hopefully I’ll be able to share some images of what I’ve been working on next week.

Friday mystery object #343 answer

Last week I gave you this mystery skull from the Ulster Museum to have a go at identifying:

If you’re a regular follower of Zygoma then you may have seen some of my previous posts talking about the skulls of the various smallish carnivores like mongooses, mustelids and viverrids. Generally though, mongooses have a more domed region above the eyes, while mustelids have a shorter snout, so this is most likely one of the viverrids.

It’s a difficult one to get down to species, since it’s from a group of carnivores that have have a fairly uniform skull shape, so it takes some detailed investigation to work out exactly what we’re dealing with. However, as I have talked about before (and as palfreyman1414 remembered), there’s a very helpful identification guide developed by some French researchers which summarises some of the most useful characters to use in identification.

Most useful to my mind is the matrix of characters that allows you to narrow down the possibilities until you’re left with the most likely species (watch out, the security certificate has expired). Once you’re down to a few possibilities based on those specific characters it can help to check the specimen images on the Animal Diversity Web which lets you get a better idea of overall shape and things like tooth form.

As it turns out, my 270th mystery object also provided a useful image for comparison:

mystery270

The reduced upper second molar (or M2) and the shape of the M1 in this specimen from the Grant Museum of Zoology is remarkably similar to the Ulster Museum specimen and it turns out it’s also from a species that made it to my shortlist using the matrix. So I’m fairly sure that this is an Abyssinian Genet Genetta abyssinica (Rüppell, 1836).

To give you an idea of what they look like, here’s a Common Genet in Wrocław Zoo by Guérin Nicolas, 2008

Well done to everyone who worked out we were dealing with a genet, but particular props to palfreyman1414 who was spot on when he said:

I’m wondering if, … this is related to the Abyssinian thingy you spent hours checking on from a complicated table of characteristics across 27 species…

Well remembered palfreyman1414, well remembered…

Friday mystery object #343

Last week I had the good fortune to visit the collections of the Ulster Museum in Belfast with the National Museums Northern Ireland’s Curator of Vertebrates Angela Ross. It’s always a valuable experience seeing other museum stores and it was a real pleasure to meet Angela and talk about our shared experiences with collections. 

As you might expect, as with every museum in the world, there are one or two specimens that have lost labels or that have never been identified, so I was fortunate enough to be get some photos of one such example for today’s mystery object. Any idea what this skull was from?

It has similarities to specimens I’ve featured in the past, and in the answers to those I’ve provided links to identification resources. If you have a rough idea of what this is, it may be worth your while using the search box in the top right corner of the blog to look for more information to help you narrow it down.

Have fun hunting for an identification – I know I will!