Michael Deak
@slothfultyrant.bsky.social
Adjunct professor at Youngstown State University who specializes in theropod and sloth thermoregulation and integument. He/Him, all opinions are my own.
Pinned
Michael Deak
@slothfultyrant.bsky.social
· Jan 14
Metabolic skinflint or spendthrift? Insights into ground sloth integument and thermophysiology revealed by biophysical modeling and clumped isotope paleothermometry - Journal of Mammalian Evolution
Remains of megatheres have been known since the 18th -century and were among the first megafaunal vertebrates to be studied. While several examples of preserved integument show a thick coverage of fur...
link.springer.com
Words cannot describe how excited I am to announce the publication of my first peer-reviewed paper published in the Journal of Mammalian Evolution! Here's a big, fancy thread summarizing everything: link.springer.com/article/10.1...
Thank you, Reddit! #PrehistoricPlanet
November 6, 2025 at 10:02 PM
Thank you, Reddit! #PrehistoricPlanet
So surreal to see something that you proposed in your first paper being brought to life later that same year. Can't wait to see more from #PrehistoricPlanetIceAge!
November 6, 2025 at 4:40 PM
So surreal to see something that you proposed in your first paper being brought to life later that same year. Can't wait to see more from #PrehistoricPlanetIceAge!
@arctomet.bsky.social (2025) "Bringing up baby: preliminary exploration of the effect of ontogenetic niche partitioning in dinosaurs versus long-term maternal care in mammals in their respective ecosystems" italianjournalofgeosciences.it/297/article-...
Bringing up baby: preliminary exploration of the effect of ontogenetic niche partitioning in dinosaurs versus long-term maternal care in mammals in their respective ecosystems
Mesozoic dinosaurs and Cenozoic mammals are often regarded as broadly ecologically equivalent, as they included the majority of medium-to-large-bodied terrestrial vertebrates of their respective eras....
italianjournalofgeosciences.it
November 6, 2025 at 1:02 PM
@arctomet.bsky.social (2025) "Bringing up baby: preliminary exploration of the effect of ontogenetic niche partitioning in dinosaurs versus long-term maternal care in mammals in their respective ecosystems" italianjournalofgeosciences.it/297/article-...
Reposted by Michael Deak
Results from the Nanotyrannus #Paleostream!
First two are N. lancensis, 3 and 4 are N. lethaeus.
You might notice some paleoart homages here ;)
#BackInHell
First two are N. lancensis, 3 and 4 are N. lethaeus.
You might notice some paleoart homages here ;)
#BackInHell
November 3, 2025 at 3:20 AM
Results from the Nanotyrannus #Paleostream!
First two are N. lancensis, 3 and 4 are N. lethaeus.
You might notice some paleoart homages here ;)
#BackInHell
First two are N. lancensis, 3 and 4 are N. lethaeus.
You might notice some paleoart homages here ;)
#BackInHell
Relevant to today's news #BackinHell
October 31, 2025 at 12:52 AM
Relevant to today's news #BackinHell
We are certainly going to look back and laugh about how this was once considered the flat earth theory of theropod paleontology.
Here's a gift link!
The Case of the Tiny Tyrannosaurus Might Have Been Cracked
www.nytimes.com
October 30, 2025 at 3:42 PM
We are certainly going to look back and laugh about how this was once considered the flat earth theory of theropod paleontology.
From the authors of the two greatest tyrannosaur books published in the last decade:
If you want a preview of Spinosaur Tales, here's a quick video of me opening up my first copies. youtube.com/shorts/fhbXO...
Unboxing the first copies of Spinosaur Tales
YouTube video by Dave Hone
youtube.com
October 29, 2025 at 7:38 PM
From the authors of the two greatest tyrannosaur books published in the last decade:
Will it be a trick? Treat? or both?
Looks like a pretty interesting paper is out this week, if you like Cretaceous dinosaurs. Oh boy.
October 28, 2025 at 8:13 PM
Will it be a trick? Treat? or both?
Reposted by Michael Deak
Yutyrannus trio closing in on Dongbeititan 🦕 inspired by how the original material for Yutyrannus was a trio of individuals possibly indicating social behavior, and then the limited material for Dongbeititan includes a rib bone with a theropod tooth embedded! #paleosky #yutyrannus #dongbeititan
October 22, 2025 at 5:26 PM
Yutyrannus trio closing in on Dongbeititan 🦕 inspired by how the original material for Yutyrannus was a trio of individuals possibly indicating social behavior, and then the limited material for Dongbeititan includes a rib bone with a theropod tooth embedded! #paleosky #yutyrannus #dongbeititan
Happy #InternationalSlothDay! Crazy to think that our little paper has been all over the place in just a short span of time. From a write-up in the New York times, to consulting on a Nat Geo infographic, to possibly seeing behaviors that we proposed on AppleTV. Am dreaming?
October 20, 2025 at 8:53 PM
Happy #InternationalSlothDay! Crazy to think that our little paper has been all over the place in just a short span of time. From a write-up in the New York times, to consulting on a Nat Geo infographic, to possibly seeing behaviors that we proposed on AppleTV. Am dreaming?
Now is the perfect time to hammer the point that we did not argue that ground sloths were as slow as tree sloths and that slow metabolism =/= slow movements! Plus, two-toed sloths can make quick swipes when they need to.
I saw someone say that the movements of the sloths in #PrehistoricPlanetIceAge are not clunky enough for a xenarthran. To that I say: wrong. Anyway, here's a giant anteater playing with a human ... www.reddit.com/r/AnimalsBei...
From the AnimalsBeingBros community on Reddit: Friendly Anteater Playing With Caretaker
Explore this post and more from the AnimalsBeingBros community
www.reddit.com
October 16, 2025 at 3:35 PM
Now is the perfect time to hammer the point that we did not argue that ground sloths were as slow as tree sloths and that slow metabolism =/= slow movements! Plus, two-toed sloths can make quick swipes when they need to.
Reposted by Michael Deak
So now you've seen TWO #PrehistoricPlanetaIceAge #sloths :) For thoughts on recent developments in sloth science, head on over to... tetzoo.com/blog/2025/10...
Sloth World, 2025 (Part 1) — Tetrapod Zoology
Like me, you are no doubt a big fan of sloths...
tetzoo.com
October 16, 2025 at 10:38 AM
So now you've seen TWO #PrehistoricPlanetaIceAge #sloths :) For thoughts on recent developments in sloth science, head on over to... tetzoo.com/blog/2025/10...
IT SQUEAKS LIKE A BABY CHOLO!!!!!! www.youtube.com/watch?v=9i0R...
Prehistoric Planet: Ice Age — Season 3 First Look | Apple TV+
YouTube video by Apple TV
www.youtube.com
October 15, 2025 at 8:24 PM
IT SQUEAKS LIKE A BABY CHOLO!!!!!! www.youtube.com/watch?v=9i0R...
It was a great honor to be in this video by @edgescience.bsky.social about what makes the Tyrant Lizard King so special. Plus I can now say that I've been in a YouTube video with @arctomet.bsky.social. #120YearsOfTrex #TyrannOThon www.youtube.com/watch?v=yE5F...
120 Years Of T. rex – What Does T. rex Mean To You? | TYRANT FILES
YouTube video by EDGE Science
www.youtube.com
October 14, 2025 at 4:28 PM
It was a great honor to be in this video by @edgescience.bsky.social about what makes the Tyrant Lizard King so special. Plus I can now say that I've been in a YouTube video with @arctomet.bsky.social. #120YearsOfTrex #TyrannOThon www.youtube.com/watch?v=yE5F...
@tetzoo.bsky.social gives us the "skinny" on recent developments in megathere integument among other things regarding sloths extinct and extant. tetzoo.com/blog/2025/10...
Sloth World, 2025 (Part 1) — Tetrapod Zoology
Like me, you are no doubt a big fan of sloths...
tetzoo.com
October 8, 2025 at 8:06 PM
@tetzoo.bsky.social gives us the "skinny" on recent developments in megathere integument among other things regarding sloths extinct and extant. tetzoo.com/blog/2025/10...
The first dinosaur eggshells from the Lance Formation. As for its identity, it could come from anything from Edmontosaurus to T. rex.
www.app.pan.pl/article/item...
www.app.pan.pl/article/item...
The first description of dinosaurian eggshell
from the Maastrichtian Lance Formation, Wyoming,
North America - Acta Palaeontologica Polonica
www.app.pan.pl
September 19, 2025 at 10:51 PM
The first dinosaur eggshells from the Lance Formation. As for its identity, it could come from anything from Edmontosaurus to T. rex.
www.app.pan.pl/article/item...
www.app.pan.pl/article/item...
@edgescience.bsky.social is putting something together to commemorate #120YearsofTrex. Anyone is free to contribute by sending in a video ansering the question "What does T. rex mean to you?" youtu.be/WWqawo1qwAA?...
TYRANN-O-THON | T. rex turns 120! Let's Celebrate ALL OCTOBER LONG!
YouTube video by EDGE Science
youtu.be
September 19, 2025 at 4:45 PM
@edgescience.bsky.social is putting something together to commemorate #120YearsofTrex. Anyone is free to contribute by sending in a video ansering the question "What does T. rex mean to you?" youtu.be/WWqawo1qwAA?...
Now this is interesting! @grahancock.bsky.social, I would love to chat if possible.
#DinoConUK @grahancock.bsky.social: How to hide a T. rex
August 17, 2025 at 3:14 PM
Now this is interesting! @grahancock.bsky.social, I would love to chat if possible.
Do you want to know something funny? John Hammond funded InGen through a grift in the Jurassic Park novel. Colossal's "dire wolves" are the real life pachyderm portfolio.
You’ll all have seen the many announcements and PR pieces from #ColossalBiosciences. There are reasons to be concerned about the general message promoted by CB, one being that it is seen >by some< (US politicians in particular) as meaning that we can devalue conservation. A 🧵 1/n
August 3, 2025 at 1:13 PM
Do you want to know something funny? John Hammond funded InGen through a grift in the Jurassic Park novel. Colossal's "dire wolves" are the real life pachyderm portfolio.
Just saw #JurassicWorldRebirth last night, and you know what "really" irked me: The animated segment playing in the museum stating how the "Neo-Jurassic age" proved catastrophic for the dinosaurs, because they couldn't adapt to cold climates.
July 6, 2025 at 12:08 PM
Just saw #JurassicWorldRebirth last night, and you know what "really" irked me: The animated segment playing in the museum stating how the "Neo-Jurassic age" proved catastrophic for the dinosaurs, because they couldn't adapt to cold climates.
With #Jaws50 falling on a #FossilFriday, the gaping jaws of 0. megalodon at
@ripleysaquariums.bsky.social of The Smokies is an appropriate showcase!
@ripleysaquariums.bsky.social of The Smokies is an appropriate showcase!
June 20, 2025 at 3:42 PM
With #Jaws50 falling on a #FossilFriday, the gaping jaws of 0. megalodon at
@ripleysaquariums.bsky.social of The Smokies is an appropriate showcase!
@ripleysaquariums.bsky.social of The Smokies is an appropriate showcase!
Yet more evidence against the scale/feather false dichotomy in the form of scaly hands and feet in #pterosaurs in addition to previous publications showing that they were fuzzy too!
www.scup.com/doi/10.18261...
www.scup.com/doi/10.18261...
June 10, 2025 at 3:45 PM
Yet more evidence against the scale/feather false dichotomy in the form of scaly hands and feet in #pterosaurs in addition to previous publications showing that they were fuzzy too!
www.scup.com/doi/10.18261...
www.scup.com/doi/10.18261...
Very interesting review paper on dinosaur physiology. Plus it's the first (proper) citation of our ground sloth thermoregulation paper! This is going to come in handy for preparing the sequel.
What can we learn about dinosaur physiology? 200 years after the 1st dino was named, new technologies yield amazing data from fossils. Physiology is vast, we hit on a few topics & gave ideas for improving hypotheses regarding how dino bodies may have worked. 🌡❤️🫁🦕🦖🧪⚒️🪶
doi.org/10.1098/rsbl...
doi.org/10.1098/rsbl...
May 29, 2025 at 4:57 PM
Very interesting review paper on dinosaur physiology. Plus it's the first (proper) citation of our ground sloth thermoregulation paper! This is going to come in handy for preparing the sequel.
A new paper by Boscaini et al. provided some interesting insights into the evolution of body size in sloths, and why the large ones went extinct. Some of the points that the authors raise align with some of our findings back in January (possible 🧵) .
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
The emergence and demise of giant sloths
The emergence of multi-tonne herbivores is a recurrent aspect of the Cenozoic mammalian radiation. Several of these giants have vanished within the past 130,000 years, but the timing and macroevolutio...
www.science.org
May 23, 2025 at 5:37 PM
A new paper by Boscaini et al. provided some interesting insights into the evolution of body size in sloths, and why the large ones went extinct. Some of the points that the authors raise align with some of our findings back in January (possible 🧵) .
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...