Douglass S Rovinsky, PhD
@dsrovinsky.bsky.social
Thylacines, sabretooths, marsupial megafauna | Palaeobiology | Morphology, Evolution, Functional Ecology | Exhibitions Content Specialist at Australian Museum (he/him)
One day shy of the #SuperMoon but as close to dark-sky conditions as I'm likely to get for a while. Taken at the Wyperfeld National Park in Victoria, Australia.
Nikon D7200
Nikkor 200-500mm at 500 mm
ISO-100
f/16
1/60 sec
Nikon D7200
Nikkor 200-500mm at 500 mm
ISO-100
f/16
1/60 sec
November 7, 2025 at 2:33 AM
One day shy of the #SuperMoon but as close to dark-sky conditions as I'm likely to get for a while. Taken at the Wyperfeld National Park in Victoria, Australia.
Nikon D7200
Nikkor 200-500mm at 500 mm
ISO-100
f/16
1/60 sec
Nikon D7200
Nikkor 200-500mm at 500 mm
ISO-100
f/16
1/60 sec
Machines of Loving Grace: “Concentration” (1993)
This is the band and the album I push on everyone. Fantastic funky, icy, aggressive, electro-rock. They never scored it big, and seemed to have faded away completely, and it’s a shame.
This album is a stunner.
This is the band and the album I push on everyone. Fantastic funky, icy, aggressive, electro-rock. They never scored it big, and seemed to have faded away completely, and it’s a shame.
This album is a stunner.
October 16, 2025 at 7:28 AM
Machines of Loving Grace: “Concentration” (1993)
This is the band and the album I push on everyone. Fantastic funky, icy, aggressive, electro-rock. They never scored it big, and seemed to have faded away completely, and it’s a shame.
This album is a stunner.
This is the band and the album I push on everyone. Fantastic funky, icy, aggressive, electro-rock. They never scored it big, and seemed to have faded away completely, and it’s a shame.
This album is a stunner.
Nitrocellulose ages almost immediately, and does so in response to the player’s body and habits.
Polyurethane does not. At all. Ever.
Now people have to pay for “custom shop faux-relic” finishes if they want a guitar that looks (and feels) like it has been played.
Polyurethane does not. At all. Ever.
Now people have to pay for “custom shop faux-relic” finishes if they want a guitar that looks (and feels) like it has been played.
October 8, 2025 at 11:44 PM
Nitrocellulose ages almost immediately, and does so in response to the player’s body and habits.
Polyurethane does not. At all. Ever.
Now people have to pay for “custom shop faux-relic” finishes if they want a guitar that looks (and feels) like it has been played.
Polyurethane does not. At all. Ever.
Now people have to pay for “custom shop faux-relic” finishes if they want a guitar that looks (and feels) like it has been played.
The thylacine did not completely overlap with any comparative. Is this an example of incomplete convergence? Perhaps!
It certainly wasn't just a marsupial wolf.
18/n
It certainly wasn't just a marsupial wolf.
18/n
October 1, 2025 at 2:12 AM
The thylacine did not completely overlap with any comparative. Is this an example of incomplete convergence? Perhaps!
It certainly wasn't just a marsupial wolf.
18/n
It certainly wasn't just a marsupial wolf.
18/n
I also found a small but significant correlation with skull shape & prey size, which points to this same idea:
The thylacine probably hunted relatively small prey & was occupying a very different functional niche than the wolf/dingo.
17/n
The thylacine probably hunted relatively small prey & was occupying a very different functional niche than the wolf/dingo.
17/n
October 1, 2025 at 2:12 AM
I also found a small but significant correlation with skull shape & prey size, which points to this same idea:
The thylacine probably hunted relatively small prey & was occupying a very different functional niche than the wolf/dingo.
17/n
The thylacine probably hunted relatively small prey & was occupying a very different functional niche than the wolf/dingo.
17/n
These canids all specialise on hunting prey much smaller than themselves. When we compare their skulls to that of the wolf or the thylacine, we can see that they are more like the thylacine skull than the wolf skull is, especially in the bitey area of the face (more white)!
16/n
16/n
October 1, 2025 at 2:12 AM
These canids all specialise on hunting prey much smaller than themselves. When we compare their skulls to that of the wolf or the thylacine, we can see that they are more like the thylacine skull than the wolf skull is, especially in the bitey area of the face (more white)!
16/n
16/n
I found that little to no significant convergence with the wolf, dingo, or red fox (the usual suspects). 🤯
BUT I did find strong signals of convergence with 4 other canids - all of which are ecologically very different than the wolf/dingo group.
15/n
BUT I did find strong signals of convergence with 4 other canids - all of which are ecologically very different than the wolf/dingo group.
15/n
October 1, 2025 at 2:12 AM
I found that little to no significant convergence with the wolf, dingo, or red fox (the usual suspects). 🤯
BUT I did find strong signals of convergence with 4 other canids - all of which are ecologically very different than the wolf/dingo group.
15/n
BUT I did find strong signals of convergence with 4 other canids - all of which are ecologically very different than the wolf/dingo group.
15/n
Here is where the thylacine fits within all these bitey critters. You can see that the shapespace of anger-faced animals is basically divided left to right into 'Cat Space' & 'Dog Land'.
The thylacine has 'moved' away from other marsupials & is hanging out near Dog Land. But closest to whom?
14/n
The thylacine has 'moved' away from other marsupials & is hanging out near Dog Land. But closest to whom?
14/n
October 1, 2025 at 2:12 AM
Here is where the thylacine fits within all these bitey critters. You can see that the shapespace of anger-faced animals is basically divided left to right into 'Cat Space' & 'Dog Land'.
The thylacine has 'moved' away from other marsupials & is hanging out near Dog Land. But closest to whom?
14/n
The thylacine has 'moved' away from other marsupials & is hanging out near Dog Land. But closest to whom?
14/n
With all this, I could drop the thylacine in and compare it to the 'known' shapes and see what that told me about its ecology.
I also used two different tests of convergent evolution. Using two tests instead of one let me 'triangulate' a more precise answer where the results overlapped.
13/n
I also used two different tests of convergent evolution. Using two tests instead of one let me 'triangulate' a more precise answer where the results overlapped.
13/n
October 1, 2025 at 2:12 AM
With all this, I could drop the thylacine in and compare it to the 'known' shapes and see what that told me about its ecology.
I also used two different tests of convergent evolution. Using two tests instead of one let me 'triangulate' a more precise answer where the results overlapped.
13/n
I also used two different tests of convergent evolution. Using two tests instead of one let me 'triangulate' a more precise answer where the results overlapped.
13/n
I measured the shapes of the skulls with 3D geometric morphometrics, which lets you collect and analyse 3D shape by placing landmarks.
The two main groups of animals (placentals and marsupials) have had a lot of time to evolve differently, so I made a protocol that would work for both groups.
12/n
The two main groups of animals (placentals and marsupials) have had a lot of time to evolve differently, so I made a protocol that would work for both groups.
12/n
October 1, 2025 at 2:12 AM
I measured the shapes of the skulls with 3D geometric morphometrics, which lets you collect and analyse 3D shape by placing landmarks.
The two main groups of animals (placentals and marsupials) have had a lot of time to evolve differently, so I made a protocol that would work for both groups.
12/n
The two main groups of animals (placentals and marsupials) have had a lot of time to evolve differently, so I made a protocol that would work for both groups.
12/n
I focused on animals that were ecologically meaningful to the question. That meant animal-eating (or 'faunivorous') mammals around the same general size as the thylacine.
I also gathered up a range of ecologic info: diet, prey size, body mass. I had to understand all the comparatives!
11/n
I also gathered up a range of ecologic info: diet, prey size, body mass. I had to understand all the comparatives!
11/n
October 1, 2025 at 2:12 AM
I focused on animals that were ecologically meaningful to the question. That meant animal-eating (or 'faunivorous') mammals around the same general size as the thylacine.
I also gathered up a range of ecologic info: diet, prey size, body mass. I had to understand all the comparatives!
11/n
I also gathered up a range of ecologic info: diet, prey size, body mass. I had to understand all the comparatives!
11/n
During my PhD I took an @artec3d.bsky.social scanner around the world to over a dozen institutions. I was interested in the ecological niche of the thylacine, & lots of info is encoded within the skull. So, I scanned a bunch of heads to compare with the thylacine's.
Hundreds of 'em.
10/n
Hundreds of 'em.
10/n
October 1, 2025 at 2:12 AM
During my PhD I took an @artec3d.bsky.social scanner around the world to over a dozen institutions. I was interested in the ecological niche of the thylacine, & lots of info is encoded within the skull. So, I scanned a bunch of heads to compare with the thylacine's.
Hundreds of 'em.
10/n
Hundreds of 'em.
10/n
Also, there is the problem of just how convergent are two groups? Convergence can be pretty damn close... or it can just be in the ballpark. And those differences can be meaningful!
What was the case with the thylacine; where did it really fit, with whom, and how closely?
9/n
What was the case with the thylacine; where did it really fit, with whom, and how closely?
9/n
October 1, 2025 at 2:12 AM
Also, there is the problem of just how convergent are two groups? Convergence can be pretty damn close... or it can just be in the ballpark. And those differences can be meaningful!
What was the case with the thylacine; where did it really fit, with whom, and how closely?
9/n
What was the case with the thylacine; where did it really fit, with whom, and how closely?
9/n
One of the issues we have is 'what does it mean to be similar to a canid?'
The thylacine has often been compared to the grey wolf or the dingo, but these are ecologically rather distinct within canids.
Canids are actually very diverse & disparate, with <35 species!
7/n
The thylacine has often been compared to the grey wolf or the dingo, but these are ecologically rather distinct within canids.
Canids are actually very diverse & disparate, with <35 species!
7/n
October 1, 2025 at 2:12 AM
One of the issues we have is 'what does it mean to be similar to a canid?'
The thylacine has often been compared to the grey wolf or the dingo, but these are ecologically rather distinct within canids.
Canids are actually very diverse & disparate, with <35 species!
7/n
The thylacine has often been compared to the grey wolf or the dingo, but these are ecologically rather distinct within canids.
Canids are actually very diverse & disparate, with <35 species!
7/n
This lets us infer hypothetical niches of some extinct animals; we can assume that these similarities meant they probably filled a similar ecological niche.
Helpful for the thylacine, since we don't have any observational data for them - only anecdotes & notes on captive animals!
5/n
Helpful for the thylacine, since we don't have any observational data for them - only anecdotes & notes on captive animals!
5/n
October 1, 2025 at 2:12 AM
This lets us infer hypothetical niches of some extinct animals; we can assume that these similarities meant they probably filled a similar ecological niche.
Helpful for the thylacine, since we don't have any observational data for them - only anecdotes & notes on captive animals!
5/n
Helpful for the thylacine, since we don't have any observational data for them - only anecdotes & notes on captive animals!
5/n
Convergent evolution can be a powerful tool for scientists, especially if you are studying an extinct animal.
If a #fossil animal has many of the same features as an unrelated living one, we can hypothesis that they were ecologically similar.
4/n
If a #fossil animal has many of the same features as an unrelated living one, we can hypothesis that they were ecologically similar.
4/n
October 1, 2025 at 2:12 AM
Convergent evolution can be a powerful tool for scientists, especially if you are studying an extinct animal.
If a #fossil animal has many of the same features as an unrelated living one, we can hypothesis that they were ecologically similar.
4/n
If a #fossil animal has many of the same features as an unrelated living one, we can hypothesis that they were ecologically similar.
4/n
One of the most obvious aspects of the thylacine is that they don't look much like any marsupial living today.
They do, however, look a lot like the placental canids (wolves, dogs & relatives) - a group separated by over 120 million years!
2/n
They do, however, look a lot like the placental canids (wolves, dogs & relatives) - a group separated by over 120 million years!
2/n
October 1, 2025 at 2:12 AM
One of the most obvious aspects of the thylacine is that they don't look much like any marsupial living today.
They do, however, look a lot like the placental canids (wolves, dogs & relatives) - a group separated by over 120 million years!
2/n
They do, however, look a lot like the placental canids (wolves, dogs & relatives) - a group separated by over 120 million years!
2/n
Found this beautiful Isopedella victorialis in my hallway yesterday morning; one of our cats* was going bonkers over her.
*the other cat couldn't care less and just wanted breakfast.
They aren't harmful, but don't like being touched by gross human fingers; I try to limit their stress of capture.
*the other cat couldn't care less and just wanted breakfast.
They aren't harmful, but don't like being touched by gross human fingers; I try to limit their stress of capture.
September 19, 2025 at 11:50 PM
Found this beautiful Isopedella victorialis in my hallway yesterday morning; one of our cats* was going bonkers over her.
*the other cat couldn't care less and just wanted breakfast.
They aren't harmful, but don't like being touched by gross human fingers; I try to limit their stress of capture.
*the other cat couldn't care less and just wanted breakfast.
They aren't harmful, but don't like being touched by gross human fingers; I try to limit their stress of capture.
The results suggest that the thylacine probably looked at anything under 8-10 kg as a tasty meal - and would have thought twice about taking things bigger than that.
This helps us build a better picture of the thylacine, their ecology, and the ecosystem they lived in.
This helps us build a better picture of the thylacine, their ecology, and the ecosystem they lived in.
August 19, 2025 at 1:44 AM
The results suggest that the thylacine probably looked at anything under 8-10 kg as a tasty meal - and would have thought twice about taking things bigger than that.
This helps us build a better picture of the thylacine, their ecology, and the ecosystem they lived in.
This helps us build a better picture of the thylacine, their ecology, and the ecosystem they lived in.
I found that the average thylacine was about 16.7 kg - much smaller than a gray wolf.
This is ecologically important, since predators smaller than ~21 kg almost always hunt animals less than half their size. Predators larger than that almost always hunt animals equal to or larger than themselves.
This is ecologically important, since predators smaller than ~21 kg almost always hunt animals less than half their size. Predators larger than that almost always hunt animals equal to or larger than themselves.
August 19, 2025 at 1:44 AM
I found that the average thylacine was about 16.7 kg - much smaller than a gray wolf.
This is ecologically important, since predators smaller than ~21 kg almost always hunt animals less than half their size. Predators larger than that almost always hunt animals equal to or larger than themselves.
This is ecologically important, since predators smaller than ~21 kg almost always hunt animals less than half their size. Predators larger than that almost always hunt animals equal to or larger than themselves.
All these methods could be cross-checked & were compared with dental (tooth or toothrow length) estimates.
I found that the limb-based estimates matched our volume-based estimates.
But the dental equations were high; not surprising, since they were built assuming the thylacine weighed ~30 kg!
I found that the limb-based estimates matched our volume-based estimates.
But the dental equations were high; not surprising, since they were built assuming the thylacine weighed ~30 kg!
August 19, 2025 at 1:44 AM
All these methods could be cross-checked & were compared with dental (tooth or toothrow length) estimates.
I found that the limb-based estimates matched our volume-based estimates.
But the dental equations were high; not surprising, since they were built assuming the thylacine weighed ~30 kg!
I found that the limb-based estimates matched our volume-based estimates.
But the dental equations were high; not surprising, since they were built assuming the thylacine weighed ~30 kg!
So, with these scans, I was able to digitally build and weigh the thylacines - based on the volume of their actual bodies.
To this I added limb-based metric estimates of their weights, because we have a lot more pieces than full mounted skeletons.
To this I added limb-based metric estimates of their weights, because we have a lot more pieces than full mounted skeletons.
August 19, 2025 at 1:44 AM
So, with these scans, I was able to digitally build and weigh the thylacines - based on the volume of their actual bodies.
To this I added limb-based metric estimates of their weights, because we have a lot more pieces than full mounted skeletons.
To this I added limb-based metric estimates of their weights, because we have a lot more pieces than full mounted skeletons.
These priceless specimens could now be brought into the computer and digitally weighed.
The taxidermy specimens would be easy - just get the volume and do some basic math (Volume = Mass/Density).
But what about the skeletons?
The taxidermy specimens would be easy - just get the volume and do some basic math (Volume = Mass/Density).
But what about the skeletons?
August 19, 2025 at 1:44 AM
These priceless specimens could now be brought into the computer and digitally weighed.
The taxidermy specimens would be easy - just get the volume and do some basic math (Volume = Mass/Density).
But what about the skeletons?
The taxidermy specimens would be easy - just get the volume and do some basic math (Volume = Mass/Density).
But what about the skeletons?
My PhD advisors Justin Adams and Alistair Evans managed to get access to the only whole-body preserved thylacine in the world, housed at the Museum of Natural History Stockholm.
This beautiful girl was scanned with our lab's @artec3d.bsky.social Space Spider.
This beautiful girl was scanned with our lab's @artec3d.bsky.social Space Spider.
August 19, 2025 at 1:44 AM
My PhD advisors Justin Adams and Alistair Evans managed to get access to the only whole-body preserved thylacine in the world, housed at the Museum of Natural History Stockholm.
This beautiful girl was scanned with our lab's @artec3d.bsky.social Space Spider.
This beautiful girl was scanned with our lab's @artec3d.bsky.social Space Spider.
I enlisted the help of Ben Myers from ThingLab & we visited Museums Victoria and TMAG in Tasmania.
There Ben used the @artec3d.bsky.social Leo 3D surface scanner to scan mounted skeletons and even taxidermy mounts.
Digital thylacines!
There Ben used the @artec3d.bsky.social Leo 3D surface scanner to scan mounted skeletons and even taxidermy mounts.
Digital thylacines!
August 19, 2025 at 1:44 AM
I enlisted the help of Ben Myers from ThingLab & we visited Museums Victoria and TMAG in Tasmania.
There Ben used the @artec3d.bsky.social Leo 3D surface scanner to scan mounted skeletons and even taxidermy mounts.
Digital thylacines!
There Ben used the @artec3d.bsky.social Leo 3D surface scanner to scan mounted skeletons and even taxidermy mounts.
Digital thylacines!