Genyornis newtoni right pes

Ah, after the millionth attempt I have been able to upload this thing! We had a hardcore thuderstorm that rattled the entire house. I think that it totally messed with the internet connection. Anyhow, down to business...

This sketch is from Rich and Vicker-Rich's Wildlife of Gondwana. This book has been my constant companion in libraries since I discovered it in Launceston College when I was in Grade 11. It has been invaluable to me because as a lowly student far away from palaeontology central in Sydney, I don't have ready access to specimens. The photography is sooo good! This is a sketch of the right foot of Genyornis newtoni. Here you can see the end point of the evolutionary trends of the dromornithids. I say end point because Genyornis was the last of its lineage, dying out some 26,000-6,000 years ago. Here you can see that the inner digit has been reduced and the increased size of the outer digit. Supposably these were adaptions to a more cursorial lifestyle as the rainforests that once blanketed Australia dried out. Unlike Dromornis stirtoni, Genyornis is more gracile and probably had a better ability to run fast. It also didn't have the massive bill that D. stirtoni.

Personally I believe that G. newtoni had a similar ecological niche to the living emu (Dromaius novaehollandiae) and fed on plants, seeds and probably invertebrates. This I believe a possibily because the emus that were comtemporaries of G. newtoni were smaller than the emus we see today. This could be due to the fact that the species competed with one another for the same resources meaning that the emus were denied of some food and suffered from a degree of stunted growth.

There are some intriguing tales from some Australian Aboriginal tribes that are suggestive of Genyornis newtoni or some other similar animal in the past. The Tjapwurong people of the Lancefield area of Victoria say that mirhirung paringmal or "Giant Emus" were living in the area when Volcanoes were active in the west. That suggests that they were around 6000 years ago at least. I also came across a legend that coud have come from the Kamilaroi People who inhabit the plains and slopes of north-west New South Wales. There is a place called the Boobera Lagoon which is thought to have once been the abode of Kurrea the rainbow serpent and his descentants are known as the Gowarkees or Gowargays, the "water emu spirits." These are also called "Giant Emus" and were said to have inhabit the swampy country near the dwelling of Baiame the All Father. These birds were black and had red legs. Could this be an ancient memory of Genyornis newtoni passed down the generations?

It would make sense if these were the birds in question. If they inhabited swamps and were more needy of water than emus, perhaps this is the reason why they did not survive to the present day.

Dromornithids, "Mihirungs" or "Thunderbirds"

When I came back to Tasmania after my wonderful time at Riversleigh smashing open limestone to get fossils, I decided that my new subject for the pen and paper would be Dromornis stirtoni. After I had drawn a pair of Thylacoleo carnifex scrapping of course. (They are not anatomically sound I know but I will get better at this.) So I pulled out Tom Rich and Pat Vickers-Rich's Wildlife of Gondwana book from the shelves of the Science Library in the University of Tasmania and sketched these dromornithid legs. I saw the skull on one of Micheal Archer's powerpoint slides as he gave a lecture in the relative cool of the evening on the warm open timber awning where we took our meals. Seeing that skull sparked my interest in Dromornis stirtoni once more. I made a quick sketch in the fleeting seconds he had it on the screen...


Here it is amongst the notes I took from Mike's lecture. I really like the shape of this skull. Look at the deep upper jaw with it's beautiful curves. It has such a good solid chin. Isn't it worth swooning over?! :-D After the lecture and all the questions were asked with the lights switched back on, I did a quick reconstruction which was based more heavily on what I remembered of emus, although these Dromornithids are only distantly related to emus. (We actually don't know how these birds are related to other avian lineages but some believe that they are related to primitive anatids, hence Dromornis stirtoni has been dubbed "The Demon Duck of Doom" because of its possible carnivorous habits; others think that they are distantly related to galliforms and it was really a gigantic mutated chook).

You can see the reconstructed head of Dromornis stirtoni lower lefthand corner above. I can do something more interesting with this animal I believe and that is what my next few posts will focus on. In this picture you can also see how I have drawn Thylacoleo carnifex and Thylacinus cynocephalus. Also, I have drawn the skeletal major structures of what I hoped to be closer to the marsupial form. I had an eye opening discussion with Henk Godthelp who told me that that the shoulder structure of marsupials is unique and the scapula is orientated more vertically. The pelvis is likewise in a more vertical position as opposed to the horizontal orientation that you see in placental mammals. Also there are more vertebrae attached to the pelvis of marsupials than those of placental mammals. The marsupial posture is kind of like a kidney bean with the back arched and the limbs held rather lower than it. This is most prominantly seen in bandicoots and wombats. Actually this posture can also be observed in mustilids like otters and ferrets. Henk told me I ought to dissect a possum, but I haven't been able to lay my paws on one yet and I don't fancy going out there and shooting one like many Tasmanians do here. I haven't had time to comb the road for roadkill so far. Micheal Archer told me that the forequarters of marsupials tend to be more well-built than the hindquarters. This can be observed in the Tasmanian Devil (Sarcophilus harrisii) in particular but also in the recently extinct Thylacinus cynocephalus. This is a carry over from the fact that when a marsupial is born, it is very underdeveloped but it does have strong forearms to pull itself through the mother's fur to the pouch. We are more likely to see this feature in Thylacoleo carnifex.

The Zoology Practical Book Cover

Righto. For those of you who have not seen this, here it is. This is the front cover of a zoology practical book that that I did in 2007. In university zoology units, it is often expected that sketches and notes of specimens, especially dissections, are taked for future reference. These drawings are ink and coloured pencil on cream card and are covered in adhesive plastic used to cover books to protect them from wear and tear. In this case, the drawings are protected from being soiled or smudged and also waterproofs the card. Now for a little something about the critters...

In the top right we have Ektopodon serratus, an unusual possum recovered from Early Miocene deposits in Riversleigh of Central Queensland and from Lake Ngapakaldi in the Tirari Desert of South Australia. Once this thirsty, arid land was covered in lush rainforest and was home to a multitude of possums. Little more than the peculiar teeth of this possum is known and those teeth were so unusual that they were once attributed to a monotreme. The molars have many cusps in two transverse rows and these have caused much confusion as to what this animal ate. So far it is thought they consumed food items that needed thorough chewing or crushing, such as nuts, seeds or insects with hard exoskeletons like beetles. Judging by the proportions of the palate and the teeth rows, as well as looking at related species like Chunia illuminata, it is thought that Ektopodon had a short snout and large orbits with the possibility of binocular vision. If this animal was still alive today I think that it would have that cute factor koalas have that make people's hearts melt into fuzziness. This would especially be the case if they were really fluffy looking like the Green ringtail possums (Psuedochirops archeri) of the Top End. I think that they would look a little like a weird cuscus and I did find a photo of the blue-eyed phase of the Common Spotted Cuscus (Spilocucus maculatus). The creamy, soft fur and the eyes sparkling back like sapphires just seemed right.

The Marsupial Lion, or Thylacoleo carnifex, is one of the most difficult animals to draw well in my opinion. I think that is this because it has many features that make it look like a felid and perhaps other things too, like possums and koalas, but it also has some very unique anatomical structures. As a result, we have one very strange looking beastie. To produce this image I found a photo of a mounted skeleton with the skull in a three-quarter view (google "Thylacoleo" images and you'll probably find the image I used) and I layered the muscles on after the method Mauricio Anton in the book he illustrated for Alan Turner. It is called The Big Cats and their Fossil Relatives. Firstly I filled in the temporalis and masseter muscles which are the ones that work the jaws. Thylacoleo had a very large fossa temporalis, through which these powerful muscles inserted, providing the animal with a very savage bite. (Steve Wroe wrote a lot about this). To bring this point across, I made these two muscles very bulky, so they bulge out over the zygomatic arch; think about the jaguar which as the strongest bite for it's size of any extant felid. Next I rounded out the whisker pads that would have sat in from of the bulge of the premolars. I had a look at the infraorbital foramen of Thylacoleo and I decided it was comparable to felids. This hole allows the nerves to pass through the skull to feed into the nerves linked to the whiskers. Cats have a large infraorbital foramen that feeds a dense bed of nerves in the whisker pads making this structure look bulky. Therefore, I ensured that Thylacoleo was well-endowed with good, dense whisker pads. The teeth were pretty hard to draw right and this animal as an unusually broad face due to the premolars projecting out to the sides more than usual. Wroe has suggested that it used its long, blade of its third premolars to bite at its prey rather than just relying on it's incisors to stab its prey to death. Naturally, when its snarls as I have illustrated it here, it should be able to expose them. For the coat I drew from the African leopard (Panthera pardus) for the sandy-orange ground colour and from quolls for the white spots. Leopards can often have green eyes. It is thought that this animal relied on stealth more than anything else to hunt, perhaps like a modern leopard. The structure of its feet are quite possum-like and it probably had a plantigrade stance, meaning that it could not run fast. However, it was probably a good climber and perhaps hunted more like an ocelot (Felis pardalis). This South America cat's modus operandi is to sit on a tree limb and wait for unsuspecting prey to pass underneath. It this instant it pounces onto it and dispatches it. It is intriguing because it suggests that Thylacoleo could have been the inspiration for the legend of the "drop bear" in Australia and indeed in life it would have had a stocky build a bit similar to one.

Zygomaturus trilobus is at the bottom of the piece. It was a diprotodontid, hence in the same family as Diprotodon optatum but in a different subfamily; the Zygomaturinae. They were characterised by complicated upper premolars that could have up to five cusps. They were browsers and inhabited rainforest up until the Pliocene when they dried out, after which they inhabited wet and dry sclerophyll forest. Pleistocene Zygomaturus articulated remains have been recovered from Tasmania. These are nearly complete, meaning that it is the best known taxa of it's lineage. "Trilobus" means "three-lobes" and this refers to three knobs located on the snout. It has been speculated that these may have supported keratin horns similar to those seen in rhinoceros today. These knobs do resemble the bony cores of rhino horns and I searched for pictures of rhinoceros to see what I could find. Since I only had profile photos of all the specimens my judgement was hindered but I decided that the shape of the Zygomaturus nasal knobs resembles those of the Indian Rhinoceros (Rhinoceros unicornis) the most. Therefore I gave it a small single nasal horn. I also gave it an upper lip similar to the black rhinoceros (Diceros bicornis) because it too is a browser. It made sense fro this animal to have pliable lips and perhaps a prehensile tongue to reach leaves above it.

Diprotodon optatum

This animal has the distinction of being the largest marsupial known, living or extinct. It weighted well over a ton and was comparable in size to a rhinoceros. The largest specimens are 3 meters long and 2 metres tall at the shoulder. Although they resembled wombats, they are not direct ancestors of them, belonging to a different subfamily; the Diprotodontidae. The Vombatidae, which is the family that modern wombats belong to, have rootless, evergrowing teeth. The Diprotodonids had rooted teeth with lower crowns, designed to browse on more succulent foliage than the roots and grasses that wombats make more use of. The structure f the nasal bones has been the source of much speculation; some think that it may have had a short trunk, others think the nasal bones resemble those of a wombats and it had a nose like theirs. I'll have to judge for myself in the future.

Diprotodon remains have been found in proximity to the Pleistocene deposits of the inland lakes of inland Australia. These creatures were one of many animals that did not make it to the present day; probably being victims of the drying climate and possibly a change in the vegetation assemblage due to the firestick farming practices of the Aboriginals. It is very likely that Diprotodon was known to the earliest people of this land and was the inspiration of the bunyip legends. It became extinct about 30,000 BP.

When I think of Diprotodon, I think of thirst. Imagine a weary lumbering beast approaching his local lake once so fertile, teeming with lungfish and crocodiles. Only to find a hypersaline puddle with salt so concentrated that it burns and cracks the parched soles of their massive feet. These animals were the equivalent of elephants in their time and elephants need to drink every day. Imagine the last drink beside the sparkling gypsum crystals of forboding beauty. Imagine the agonised eyes sunken with starvation and the drawn, gaunt face drawing up the last particles of moisture from the spreading dust of the desert.

Simosthenurus

I think I did this drawing in 2006. I know these things are a bit old now, but I don't have enough time to scan off my later drawings at the moment. I really should be studying but I find this little journal a fulfilling catharsis in my dreary life...

Anyhow, this is a profile of Simosthenurus sp. that I did directly from a photo of a skull that I found in Vickers-Rich and Rich's Wildlife of Gondwana. This book has been a useful companion for me as I don't have good access to specimens. Yes, so I sketched the skull and layered the muscles on as well as I understood it. If you look at it closely, you can still see the outline of the zygomatic arch, teeth, diastema and the end of the nasal bones where they adjoin the rhinarium. It is also possible to view where I have blocked out the temporalis and masseter muscles as well as the whisker pads.

Simosthenurus ("short-nosed strong-tailed beast") was a sthenurine; a member of an extinct lineage of browsing kangaroos. They are characterised by short, deep muzzles, high-crowned molars with complex crenulated enamel, short robust tails and often they only had one well developed toe (digit 4) on their hind feet. Their bones suggest that they were also heavily built, I might enjoy drawing one of these on steroids! They were often quite gigantic, larger than modern kangaroos. Procoptodon goliah could have been up to three metres tall and is the largest kangaroo known. Simosthenurus itself could have weighed about 100 kilograms; larger than any living kangaroo. It is thought that sthenurines were amongst the first macropods to move out into the woodlands that were replacing the rainforests as Australia dried out in response to the Ice Ages. The short jaws probably gave them a stronger bite, allowing them to masticate tougher vegetation and the monodactylism could be a convergence with horses. It might have allowed them to hop around at higher speeds. Both Procoptodon and Simosthenurus lived during the Late Pleistocene; about 1 mya to 500,000 BP.