Biology Ancient Australia (Extinct Megafauna, Dinosaurs etc)

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CD Xbow said:
Eight fossilised feathers were found last year in creatceous strata from Koonwarra, one of which looks 'non avian', unfortunately not found with any bones associated. See http://thestar.com.au/blog/world-first/ The only picture I could find is this one, which looks pretty avian, but I'm no expert.


The Koonwarra bed has had some spectacular insect & fish finds - see https://stephenporopat.weebly.com/u..._and_fish...and_feathers_for_good_measure.pdf He also recently published a review of all the early cretaceous biotas in southern australia - see https://www.researchgate.net/public...ern_Australia-an_overview_of_research_to_date Covers plants, vetebrates and invetebrates. Proper paper, not for the feint hearted.
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Can't see any barbules on the feather so probably not from an animal that flies. Looks like it is from a theropodic (avian) dino maybe but I'm not expert.

going by the article Qantassaurus is probably the likely suspect for the non avian feather
 
Wizard17 said:
Can't see any barbules on the feather so probably not from an animal that flies. Looks like it is from a theropodic (avian) dino maybe but I'm not expert.

going by the article Qantassaurus is probably the likely suspect for the non avian feather
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Certainly could be a non avian therapod. I haven't been able to find an image of the most 'simple' feather. The feathered ornithopods from northern hemisphere dinos have had a few different types of feather, clever Kulindadromeus had three, from wikipedia:

"The feather remains discovered are of three types, adding a level of complexity to the evolution of feathers in dinosaurs.[2]The first type consists of hair-like filaments covering the trunk, neck and head. These are up to three centimetres long and resemble the stage 1 "dino-fuzz" already known from theropods like Sinosauropteryx. The second type is represented by groups of six or seven downwards-projecting filaments up to 1.5 centimetres long, originating from a base plate. These are present on the upper arm and thigh. They resemble the type 3 feathers of theropods. The base plates are ordered in a hexagonal pattern but do not touch each other. The third type is unique. It was found on the upper lower legs and consists of bundles of six or seven ribbon-like structures, up to two centimetres long. Each ribbon is constructed from about ten parallel filaments up to 0.1 millimetres wide"
 
Considering that Australia was closer to the south pole in the Cretaceous it wouldn't be too far fetched to expect our Ornithopods to have had some sort of insulating feathers. Actually would expect it. Same goes with Avian Theropods like Australovenator.
 

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Wizard17 said:
Considering that Australia was closer to the south pole in the Cretaceous it wouldn't be too far fetched to expect our Ornithopods to have had some sort of insulating feathers. Actually would expect it. Same goes with Avian Theropods like Australovenator.
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Yes, I believe that's the common believe by the local paleo's. It would be ideal to be getting more material from specimens from Koonwarra, finding some bones and feathers in close association. I may be wrong, but I don't think there are currently any digs going on, most of the previous materials were related to road cuttings.

I've been trying to 'protofeather' one of the Leaellynasaura models I have built, but so far it hasn't gone well for technical reasons. The original 2 I've done what I call the 'full crocodile', but they look like they would be very, very cold. I decided I needed an 'analog', and used Kulindadromeus, Tom Parker has done an illustration, showing the 3 feathers and 3 types of scales. The bottom illustration is Tom's original layered over a skeleton, the top one I have tried to realistically posture it, color it etc. Unfinished at present and may stay that way.
Kulindadromeusr_recon_small.jpg ​
 
CD Xbow said:
Yes, I believe that's the common believe by the local paleo's. It would be ideal to be getting more material from specimens from Koonwarra, finding some bones and feathers in close association. I may be wrong, but I don't think there are currently any digs going on, most of the previous materials were related to road cuttings.

I've been trying to 'protofeather' one of the Leaellynasaura models I have built, but so far it hasn't gone well for technical reasons. The original 2 I've done what I call the 'full crocodile', but they look like they would be very, very cold. I decided I needed an 'analog', and used Kulindadromeus, Tom Parker has done an illustration, showing the 3 feathers and 3 types of scales. The bottom illustration is Tom's original layered over a skeleton, the top one I have tried to realistically posture it, color it etc. Unfinished at present and may stay that way.
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Wonder if they could find any fossilised melanin in the feathers to work out the colours. Been done elsewhere with other fossils.
 
Wizard17 said:
Talking about Ornithopods a new species was found up at lightning ridge.
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"Weewarrasauras pobeni is the first dinosaur to be named in New South Wales in almost a century, following a chance discovery of a jawbone fragment in a bucket of opal rubble near Lightning Ridge."

Like most Australian finds it's pretty sparse, part of a jawbone, clearly another ornithopod. We must have had a lot of chicken/turkey sized ornithopods running around Oz in the Cretaceous.

Wizard17 said:
Wonder if they could find any fossilised melanin in the feathers to work out the colours. Been done elsewhere with other fossils.
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I think it's the fossilised melanosomes rather than the melanin, they work out the colour by comparing the shape of the fossil melanosomes to melanosomes from extant birds, it's not just the type of pigment melanosomes produce, it's also their arrangement which produces colouration by 'structural coloration' effects, eg irridescence.
 
https://mobile.abc.net.au/news/2018...na-bones-south-australia/10599218?pfmredir=sm

A cave diver has uncovered a globally significant collection of ancient bones from Australia's prehistoric period in the dark depths of South Australia's underwater caves.

The chance discovery was made in Mount Gambier's longest and largest cave system, having been hidden from human eyes for thousands of years.

The jaw bones and teeth from extinct megafauna were in a chamber about 1 kilometre from the entrance to Tank Cave, located on private property.

Local cave diver Ryan Kaczkowski said he was exploring the cave system when he found the "new room" containing the bones.

"It's a large collection of bones and they're strewn about the place, so I was able to document them and take photos and get some sizing," Mr Kaczkowski said.

He sent the images and details to palaeontologists and was told the bones belonged to several extinct species, including the short-faced kangaroo and the marsupial lion.

Mr Kaczkowski said it was not unusual to find bones near cave entrances, but it was rare to come across them this deep into a cave system.

"What it means is that it would have been an entrance — some kind of pit or collapse a long, long time ago and it was open so land animals could maybe live in it, or fall into it and at some point it was closed over, so it's contained and preserved what's fallen in," he said.

"The room itself has obviously never been entered by anyone or anything, so suddenly to get into that and see that is quite a special experience."

He said he was careful not to disturb the bones, and instead surveyed their location and took measurements.

Palaeontologist 'envious' of discovery
It's this approach that has drawn the praise of fellow cave diver and palaeontologist Julien Louys from Griffith University.

"It's best to leave them in place so professionals can assess and work out the best way to extract those fossils, so we don't lose any scientific information," Dr Louys said.

"In any system whatsoever, whether it's a dry cave, a wet cave or even out in the open, if you find fossils, as soon as you take them out of their context you lose a huge amount of information."

Dr Louys said this find was "particularly significant" because it contained obvious examples of extinct megafauna.

"Bones are relatively common in some of these flooded caves but most of the time they're quite modern, quite recent. We're talking maybe in the last few thousand years or so," Dr Louys said.

"Not just for Australia but all around the world it's quite rare to find such old material in these flood caves."

He said such ancient fossils were usually "cemented" into the floors and walls of dry caves, making it more challenging to extract them. They were also more prone to being destroyed and weathered away over time.

"Ryan is just incredibly privileged [because] he's probably the first person in the last few hundred thousand years who's actually laid eyes on these fossils. I'm more than just a little bit envious," he said.

Discovery unlikely to be the last
One of the species identified among the fossils — the marsupial lion (Thylacoleo carnifex) — was the largest carnivorous Australian mammal in the Pleistocene epoch.

An ambush predator, the animal's enormous scissor-like teeth, used in conjunction with a large thumb claw, meant it would be able to dispatch much larger prey quite easily.

University of Adelaide palaeontologist Liz Reed, who is based at the world-heritage-listed Naracoorte Caves, said there had been many discoveries of these types of fossils in the south-east of South Australia.

"I often joke that the Naracoorte Caves are the world headquarters for the Thylacoleo — we've found more [here] than anywhere else," Dr Reed said.

Mr Kaczkowski was excited to put on his wetsuit again and return to the site of his amazing discovery.

The Cave Diving Association of Australia is working on a grant to potentially excavate and preserve the site.

"I dive it every week, so 100 per cent I'll be back with my suit on and back out there as soon as you know it," he said.

"There's always the possibility of more and that's part of the drawcard of the sport I suppose. There are literally hundreds of dive sites that we know about here that we're waiting to explore.

"It's going to be an ongoing discovery."
 
More feathers, this time from Burmese amber - https://www.sciencealert.com/ancien...on-years-ago-had-really-really-weird-feathers These one are real oddballs having a U shaped rachis (central shaft), these are usually a cylinder. it is certainly looking like 'feathers' of some sort are pretty basal for archosaurs. Embryonic crocs have the genetic machinery to make the feather keratin, it's just not expressed in life, and they only make the keratin that forms scales.
 
https://mobile.abc.net.au/news/2018...ted-earlier-than-thought/10632046?pfmredir=sm

A microscopic examination of fossils from China has revealed the fur-like body covering of pterosaurs, the flying reptiles that lived alongside dinosaurs, was actually made up of rudimentary feathers.

The surprising discovery described by scientists means dinosaurs and their bird descendants were not the only creatures to boast feathers, and feathers likely appeared much longer ago than previously known.

Pterosaurs were only distantly related to dinosaurs and birds.

Birds need feathers to fly. That was not the case with pterosaurs.

Short, hair-like feathers covered their bodies and wings but lacked the strong central shaft of avian flight feathers, the researchers said.

They may have provided insulation and other benefits, as hair does for mammals.

"They were not flight feathers," palaeontologist Baoyu Jiang of Nanjing University, who led the research, said.

"They looked fuzzy, and they didn't have complicated feathers."

The researchers examined beautifully preserved Jurassic Period fossils roughly 160-165 million years old of two small pterosaurs called anurognathids from north-eastern China.

Apparently forest dwellers and insect eaters, they possessed 45-centimetre wingspans, short tails and superficially frog-like faces.

Pterosaurs were the first vertebrates to master flight, followed much later by birds and bats.

Scientists have known since the 19th century that pterosaurs had a fur-like body covering and there has been a long-running scientific debate about how to classify it.

Many of the filaments, under the microscope, showed branching like in feathers but not hair.

University of Bristol palaeontologist and study co-author, Mike Benton said four types of pterosaur feathers were observed: downy feathers, single filaments, bundles of filaments, and filaments with tufts at the end

Tiny pigment-related structures indicated these feathers were ginger-brown in colour.

Birds, many meat-eating dinosaurs and some plant-eating dinosaurs are known to have had feathers, though these looked different from those seen on the pterosaurs.

"We feel the simplest thing for the present is to call them all feathers because they show branching, the fundamental distinguishing character of a feather," Mr Benton said.

Pterosaurs and dinosaurs both appeared roughly 230 million years ago during the Triassic Period.

The researchers said the appearance of feathers in both groups suggests feathers first evolved perhaps 250 million years ago in a common ancestor of pterosaurs and dinosaurs.

Pterosaurs, the biggest of which had 10.7-metre wingspans, went extinct along with the dinosaurs after an asteroid impact 66 million years ago.
 
Wizard17 said:
https://mobile.abc.net.au/news/2018...ted-earlier-than-thought/10632046?pfmredir=sm

A microscopic examination of fossils from China has revealed the fur-like body covering of pterosaurs, the flying reptiles that lived alongside dinosaurs, was actually made up of rudimentary feathers.

The surprising discovery described by scientists means dinosaurs and their bird descendants were not the only creatures to boast feathers, and feathers likely appeared much longer ago than previously known.

Pterosaurs were only distantly related to dinosaurs and birds.

Birds need feathers to fly. That was not the case with pterosaurs.

Short, hair-like feathers covered their bodies and wings but lacked the strong central shaft of avian flight feathers, the researchers said.

They may have provided insulation and other benefits, as hair does for mammals.

"They were not flight feathers," palaeontologist Baoyu Jiang of Nanjing University, who led the research, said.

"They looked fuzzy, and they didn't have complicated feathers."

The researchers examined beautifully preserved Jurassic Period fossils roughly 160-165 million years old of two small pterosaurs called anurognathids from north-eastern China.

Apparently forest dwellers and insect eaters, they possessed 45-centimetre wingspans, short tails and superficially frog-like faces.

Pterosaurs were the first vertebrates to master flight, followed much later by birds and bats.

Scientists have known since the 19th century that pterosaurs had a fur-like body covering and there has been a long-running scientific debate about how to classify it.

Many of the filaments, under the microscope, showed branching like in feathers but not hair.

University of Bristol palaeontologist and study co-author, Mike Benton said four types of pterosaur feathers were observed: downy feathers, single filaments, bundles of filaments, and filaments with tufts at the end

Tiny pigment-related structures indicated these feathers were ginger-brown in colour.

Birds, many meat-eating dinosaurs and some plant-eating dinosaurs are known to have had feathers, though these looked different from those seen on the pterosaurs.

"We feel the simplest thing for the present is to call them all feathers because they show branching, the fundamental distinguishing character of a feather," Mr Benton said.

Pterosaurs and dinosaurs both appeared roughly 230 million years ago during the Triassic Period.

The researchers said the appearance of feathers in both groups suggests feathers first evolved perhaps 250 million years ago in a common ancestor of pterosaurs and dinosaurs.

Pterosaurs, the biggest of which had 10.7-metre wingspans, went extinct along with the dinosaurs after an asteroid impact 66 million years ago.
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Even more feathers!
I'm waiting for the fluffy crocodile!!
It certainly appears that making complex keratin based skin coverings is a feature of archosaurs, and dates back to about 250 mya. The crocodylomorphs managed scales, scutes etc, with the pterosaurs and the dinos adding all sorts of 'feather' structures, up to and including the complex feathers of modern birds. I suspect it's related to their physiology, having a higher metabolic rate, a more vigorous lifestyle and being, in vary degrees endothermic. Here is a easily read article about early archosaurs https://www.fossilhunters.xyz/dinosaur-age/basal-archosaurs-before-the-dinosaurs.html
 
https://www.abc.net.au/news/science...our-pigmentation-birds-palaeontology/10452812

Eggshells come in a dazzling range of colours and patterns, from the vivid blue of a robin to the deep brown speckles on quail eggs. And it seems modern birds have their dinosaur ancestors to thank for this kaleidoscope of colour.

Palaeobiologists in the US and Germany looked for blue-green and red-brown pigments in a range of fossilised dinosaur eggshells.

They found traces of colour in eggs laid by dinosaurs closely related to modern-day birds — tiny two-legged insect-eaters — but not in those belonging to massive, lumbering brachiosaurus-like titanosaurs.

The study, led by Jasmina Wiemann of Yale University and published in Nature, suggests egg colour evolved in dinosaurs and was inherited by the birds we see today.

Two pigments produce a rainbow of colours
The whole gamut of egg colouration in modern birds is supplied by just two pigments.

Biliverdin gives eggshells a bluish-green hue, while protoporphyrin bestows red-brown, including smatterings of spots and speckles.

Why a bird's egg is patterned or coloured depends on a few factors, said Karen Rowe, an ornithologist at the Melbourne Museum.

Camouflage is a big one. Birds that nest on the ground, for instance, have eggs coloured to blend in to their surroundings.

Pigments might also protect against ultraviolet damage to the developing embryo; help birds determine if, say, a cuckoo has laid an egg in their nest and; for birds that nest in a colony, colouration can help them identify their own eggs among the rest.

"Many of these factors may simultaneously drive the evolution of the actual colouration we see on eggs and there's still a great deal of individual variation within some species," Dr Rowe said.

But coloured eggs require resources to create. In some circumstances, white eggs are preferable, Australian Museum bird palaeontologist Jacqueline Nguyen said.

"In living birds, eggs that are buried or covered, or laid in a cavity nest or burrow, tend to be white, where there's no need to conceal them," Dr Nguyen said.

"Another benefit is in cavity nests, like the hollow of a tree, a white egg is more visible to the parents, so they might be less likely to damage it."

When eggshell pigmentation arose, though, has been a mystery. Did birds' ancestors, the dinosaurs, lay coloured eggs, or did birds evolve that ability later down the line?


Pigments in some eggs, but not in others
To find an answer to this question, Dr Wiemann and her colleagues turned to a non-destructive technique called Raman spectroscopy to analyse the chemical composition of a collection of fossilised dinosaur eggs.

Most were from a group of dinosaurs called Maniraptora, which included early birds and closely related non-avian dinosaurs. But they also included other groups, such as sauropods.

"We incorporated [an eggshell from the Maniraptor] dinosaur that was used to design the velociraptor in Jurassic Park, Deinonychus," Dr Wiemann said.

"Their eggs were very much comparable to emu eggs — probably an intense, dark blue, maybe with brown speckles all over."

Even the most vibrant eggshell pigments fade over tens of millions of years, but they do leave tiny traces behind.

Dr Wiemann and her crew found pigments in eggs laid by Maniraptora, but not in those belonging to other dinosaur groups.

To be sure the pigment traces in the eggs were present when they were laid, and didn't seep in from its surrounds, the team also checked for pigments in the sediments around the eggs.

They found none.

Next up: more eggs from birds, alive and dead
Dr Rowe found it surprising that coloured eggshells seem to have originated with dinosaurs, mostly because out of the living descendants of dinosaurs, only birds lay coloured eggs — reptiles and egg-laying mammals don't.

"If they had, it would have been more likely that dinosaurs had coloured eggs as a shared trait uniting this large group," she said.

While Raman spectroscopy is one line of evidence, Mary Schweitzer, a palaeontologist at North Carolina State University who was not involved in this study, said analysing proteins in the fossilised eggshells would give weight to the findings.

Eggshells contain a protein scaffold, and pigments are only found in this structure. In other words, where you find pigment, you should find protein.

"I think it's a really interesting study, and I would like to see data for protein," Dr Schweitzer said.

"It would certainly give you another line of evidence that the origin of pigment in eggshells originated in Manoraptora."

Mapping the pigmentation of entire eggshell fragments, rather than a few points, would also provide a clearer picture of speckling or spotting patterns.

"If I give you a magpie feather and you sample [the pigment on] three points, you're not going to get [a picture of] a magpie from that," Dr Schweitzer said.

Next, Dr Wiemann and her colleagues plan to use Raman spectroscopy to examine more eggshells, including modern birds.

Dr Nguyen would like to see the technique on the fossilised eggshells of extinct birds too.

"It opens up a lot more doors into further studies," she said.
 
"Dr Rowe found it surprising that coloured eggshells seem to have originated with dinosaurs, mostly because out of the living descendants of dinosaurs, only birds lay coloured eggs — reptiles and egg-laying mammals don't."

Dr Rowe must be living in the 1950. Birds are dinosaurs, so why is it surprising?
 

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We certainly are continuing the special on small Victorian ornithopds, another ones been described, from near Inveloch https://www.abc.net.au/news/science/2019-03-11/wallaby-sized-dinosaur-from-victorian-coast/10878984 Galleonosaurus dorisae was found at the 125 million-year-old Flat Rock site and that makes it the fifth Ornithopod from along the Victorian coastline. And, as is typical with Australian dinos, another relatively sparse specimen. Very nice map of Cretaceous Australia in the ABC article.
 
Ambopteryx. Not Australian, but a dino flyer with a wing membrane, like a bat. Probably a glider I suspect, the video portrays it as that. Remember it's from the Jurassic, not one of the many cretaceous maniraptors. Probably only had simple feathers on their bodies with long tail feathers.

https://www.nationalgeographic.com/...w-species-bat-wing-dinosaur-discovered-china/

The article says some authors believed flying evolved 4 times amongst dinos. I could get 4 from the Archosaurs:

Pterosaurs - which aren't really dinosaurs
Maniraptors -------> extinct dinos separately from birds
------> birds
Scansoriopterygidae (eg ambopteryx)
 
Rusty Brookes said:
Great thread. CD XBow your re-constructions are brilliant.
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Special treat for you.
Diprotodon skull. An A3 sized drawing I did last year and only got around to photographing and cleaning up digitally recently. I drew it from a 3D model skull which was only about 30cm long - 1/10 scale approx. It was only when I added the human skulls that I realized how big these were. 3 Tons is a big beasty. Happy for people to use it in any way they wish, except commercial - its released with a CC licence - non commercial see - https://creativecommons.org.au/learn/licences/

Diprotodon-optatum1000x1500.jpg
 
This is another skull, this time the common wombat (Vombatus ursinus), not an extinct animal but certainly one whose range is becoming increasingly restricted. It's a beautiful work, done by the late Victoria Newman. The skull was found around Sandy Point some years ago by my kids, and I commissioned Victoria to draw it for me a couple of years ago. I think it was the last work she did before she tragically suicided. She was so pleased with it.

wombat-titled-victoria-1000x1394.jpg
Again I'm releasing this with a CC BY-NC-SA license - see https://creativecommons.org/licenses/

I also would ask you to spare a thought for Victoria, say a prayer if you are of a faith, there are far too many lost souls in this world. Be kind to yourself and others.
 

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