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.
#PrehistoricPlanetIceAge accurately reflects the diverse array of hairstyles that ground sloths likely had throughout their range that we state in our paper, and I cannot wait to see more.
November 17, 2025 at 5:18 PM
#PrehistoricPlanetIceAge accurately reflects the diverse array of hairstyles that ground sloths likely had throughout their range that we state in our paper, and I cannot wait to see more.
A lot of things happened between the work for my thesis and the peer-reviewed version, as most things in science do. Our initial results presented at conferences suggested regional variation in integument (as per this illustration by
@fossilfracas.com)
@fossilfracas.com)
November 17, 2025 at 5:17 PM
A lot of things happened between the work for my thesis and the peer-reviewed version, as most things in science do. Our initial results presented at conferences suggested regional variation in integument (as per this illustration by
@fossilfracas.com)
@fossilfracas.com)
I feel the need to address some comments that have been popping up here and there regarding the #Eremotherium design for #PrehistoricPlanetIceAge. To people saying that our paper fully refutes a sparse coat of fur in this genus, here is what we actually say:
November 17, 2025 at 5:16 PM
I feel the need to address some comments that have been popping up here and there regarding the #Eremotherium design for #PrehistoricPlanetIceAge. To people saying that our paper fully refutes a sparse coat of fur in this genus, here is what we actually say:
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!
Relevant to today's news #BackinHell
October 31, 2025 at 12:52 AM
Relevant to today's news #BackinHell
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?
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...
The findings suggest that #sloths evolved into giants at least three times independently, and large body sized coincided with cold climates, and that humans were a likely cause of the extinction of ground sloths.
May 23, 2025 at 5:37 PM
The findings suggest that #sloths evolved into giants at least three times independently, and large body sized coincided with cold climates, and that humans were a likely cause of the extinction of ground sloths.
I've finally received my copy of @markwitton.bsky.social's King Tyrant! I've never been this excited to dive into a tyrannosaur book since @davehone.bsky.social's Tyrannosaur Chronicles as an undergrad. Here's hoping it feeds me more ideas to test in future papers. #FossilFriday
May 16, 2025 at 7:27 PM
I've finally received my copy of @markwitton.bsky.social's King Tyrant! I've never been this excited to dive into a tyrannosaur book since @davehone.bsky.social's Tyrannosaur Chronicles as an undergrad. Here's hoping it feeds me more ideas to test in future papers. #FossilFriday
Never in a million years did I think that my name would be in National Geographic this early in my career. Huge congrats and thanks to @fracas.bsky.social for bringing the #sloths of the past back to life in this incredible infographic and for having Dr. Butcher and I on board as consultants!
April 21, 2025 at 11:21 PM
Never in a million years did I think that my name would be in National Geographic this early in my career. Huge congrats and thanks to @fracas.bsky.social for bringing the #sloths of the past back to life in this incredible infographic and for having Dr. Butcher and I on board as consultants!
Legitimate question, Plos: Why are we randomly cited in papers that have next to nothing to do with molecular studies? It's not as bad as getting miscited in a paper about advanced vehicle classification, but......come on.
April 17, 2025 at 6:02 PM
Legitimate question, Plos: Why are we randomly cited in papers that have next to nothing to do with molecular studies? It's not as bad as getting miscited in a paper about advanced vehicle classification, but......come on.
The struggle to gain traction is real.....
April 16, 2025 at 5:36 PM
The struggle to gain traction is real.....
Is it just me, or does this shot in #JurassicWorldRebirth give AI "art" vibes?
February 5, 2025 at 9:00 PM
Is it just me, or does this shot in #JurassicWorldRebirth give AI "art" vibes?
Even though our findings largely casts doubt on the "hairless model of integument" in most cases, blanket statements like this undermine the degree of integumentary variation between populations in deep time. @fracas.bsky.social hit the nail on the head with this wonderful infographic.
February 3, 2025 at 1:45 PM
Even though our findings largely casts doubt on the "hairless model of integument" in most cases, blanket statements like this undermine the degree of integumentary variation between populations in deep time. @fracas.bsky.social hit the nail on the head with this wonderful infographic.
Looking back at Dececchi et al. (2020), I just realized that the findings in our recent paper on #groundsloth thermal energetics may have more applications for #Tyrannosaurids than I initially realized. Both were getting "metabolic mileage" by using energy saving adaptations.
January 29, 2025 at 6:48 PM
Looking back at Dececchi et al. (2020), I just realized that the findings in our recent paper on #groundsloth thermal energetics may have more applications for #Tyrannosaurids than I initially realized. Both were getting "metabolic mileage" by using energy saving adaptations.
While we had a decent sample size for our recent paper on #groundsloth physiology and integument, there were a few that unfortunately didn't make the final cut. One such specimen was this #Eremotherium tooth from the Talara tar pits in Peru. #FossilFriday
January 17, 2025 at 2:07 PM
While we had a decent sample size for our recent paper on #groundsloth physiology and integument, there were a few that unfortunately didn't make the final cut. One such specimen was this #Eremotherium tooth from the Talara tar pits in Peru. #FossilFriday
Also, HUGE shout-out to @haiderjaffri.bsky.social for doing not one, but two excellent pieces of art for the paper!
January 14, 2025 at 5:07 PM
Also, HUGE shout-out to @haiderjaffri.bsky.social for doing not one, but two excellent pieces of art for the paper!
And I'll end this with the following question: in a 4-5,000 kg. sloth can be just fine with a fairly thick coat in temperate settings (albeit due to a low metabolic rate), what does that mean for similarly-sized amniotes in deep time? Am I teasing a sequel? Maybe...
January 14, 2025 at 4:45 PM
And I'll end this with the following question: in a 4-5,000 kg. sloth can be just fine with a fairly thick coat in temperate settings (albeit due to a low metabolic rate), what does that mean for similarly-sized amniotes in deep time? Am I teasing a sequel? Maybe...
But why didn't ground sloths invest in higher metabolic rates? We suggest that the low metabolic rates allowed for ground sloths to get more "metabolic mileage" to avoid ecological competition with other large herbivores pre and post GABI. Art by Benjamin R. Langlois.
January 14, 2025 at 4:34 PM
But why didn't ground sloths invest in higher metabolic rates? We suggest that the low metabolic rates allowed for ground sloths to get more "metabolic mileage" to avoid ecological competition with other large herbivores pre and post GABI. Art by Benjamin R. Langlois.
Our models also predict a thick coat for #Mylodon and #Nothrotheriops which is consistent with the preserved #fossil integument that we have for them.
January 14, 2025 at 4:20 PM
Our models also predict a thick coat for #Mylodon and #Nothrotheriops which is consistent with the preserved #fossil integument that we have for them.
So how did a decrease in metabolic rate affect the fuzziness of ground sloths? Surprisingly, quite a bit! Our results suggest prominent cold stress for a sparsely furred ground sloth save for populations of #Eremotherium near the equator. Art by @joschuaknuppe.bsky.social
January 14, 2025 at 4:12 PM
So how did a decrease in metabolic rate affect the fuzziness of ground sloths? Surprisingly, quite a bit! Our results suggest prominent cold stress for a sparsely furred ground sloth save for populations of #Eremotherium near the equator. Art by @joschuaknuppe.bsky.social
Needless to say, Fariña's hypothesis was largely forgotten until it was revitalized in the wake of similar discussions on thermal neutrality and integument in large #dinosaurs. @markwitton.bsky.social's blog and art proved to be very influential on my end.
January 14, 2025 at 3:35 PM
Needless to say, Fariña's hypothesis was largely forgotten until it was revitalized in the wake of similar discussions on thermal neutrality and integument in large #dinosaurs. @markwitton.bsky.social's blog and art proved to be very influential on my end.
For over two centuries, this is how giant #sloths such as #Megatherium were depicted in art and media. But how credible are these extensively furry reconstructions?
January 14, 2025 at 3:26 PM
For over two centuries, this is how giant #sloths such as #Megatherium were depicted in art and media. But how credible are these extensively furry reconstructions?