Michael Deak
banner
slothfultyrant.bsky.social
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
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...
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
Hot take: NIT (Nanotyrannus is Tyrannosaurus) is going to be the new BAND (birds are not dinosaurs).
January 6, 2026 at 10:12 PM
Reposted by Michael Deak
Some people really do be like:
"nah, our modern day image of dinosaurs is boring and stupid"...
December 29, 2025 at 6:33 AM
The last bombshell paleontology discovery of a year of bombshell discoveries: Ammonites survived the K-PG extinction! www.nature.com/articles/s41...
Ammonite survival across the Cretaceous–Paleogene boundary confirmed by new data from Denmark - Scientific Reports
We provide a reassessment of the hypothesis of ammonite survival across the Cretaceous–Paleogene (Maastrichtian–Danian) boundary, based on new data from the lower Danian Cerithium Limestone Member at ...
www.nature.com
January 1, 2026 at 2:16 PM
2025 was a year packed with a multitude of discoveries, and I am grateful my first paper was among them. First order of business of 2026: Continue working on the sequel.....
January 1, 2026 at 2:12 PM
Reposted by Michael Deak
shout-out to @literallymiguel.bsky.social for having his art featured in a new publication! the study by wilson and zonneveld describes feeding traces on the holotype of the bolivian glyptodont trachycalyptoides
www.tandfonline.com/doi/full/10....
December 29, 2025 at 1:43 PM
Reposted by Michael Deak
People always draw Nanotyrannus attacking Juvenile Tyrannosaurus, so I am doing something different
December 25, 2025 at 3:48 AM
Reposted by Michael Deak
A very Merr Chrismas to all you hoomans out there, from Prehistoric Planet: Ice Age's Megalonyx family!

Wishing you a safe and happy holiday!

#PrehistoricPlanet #PrehistoricPlanetIceAge #paleoart #groundsloth #Christmas #meme
December 24, 2025 at 3:47 PM
Reposted by Michael Deak
Result from the Talara tar seeps #paleostream! Like the La Brea tar pits this was Pleistocene death trap, however these fossils come from Peru so everything has a south american flavor. This piece is set at the beginning of the rainy season, with new green beginning to sprout...
December 17, 2025 at 2:52 AM
Reposted by Michael Deak
Excited to announce that my second manuscript, “Fossilised Melanosomes Reveal Colour Patterning in A Sauropod Dinosaur” has been published in
@royalsociety.org !! Diplodocus scales are complex and diverse, and it turns out their color patterning was even more so. A 🧵🦕 1/26
December 10, 2025 at 3:14 PM
Reposted by Michael Deak
In light of @tessasaurus.bsky.social's amazing paper on paleocoloration of the MDQ Diplodocus, I would *highly* recommend those interested to check out @zhejiang0pterus.bsky.social's paleo color doc! they've done great work researching it and have been very responsive to sources I've found for it. 👇
December 10, 2025 at 6:41 PM
Huge congrats to @tessasaurus.bsky.social et al. on this excellent paper regarding the first sauropod melanosomes! royalsocietypublishing.org/rsos/article...
Fossilized melanosomes reveal colour patterning of a sauropod dinosaur
Abstract. Integumentary fossils have improved understanding of dinosaur physiology, appearance and ecological niches. Fossil melanin and fossil melanosome
royalsocietypublishing.org
December 10, 2025 at 1:08 PM
26 years of intense debate that boarded on blood feuds and this all could have been resolved if we just cut open the hyoids of CMNH 7541.....

Incredible work!
Very excited to share that our latest paper is out in Science! We show that the type specimen of Nanotyrannus—an isolated skull—is fully grown, showing that it is not a juvenile Tyrannosaurus rex but a distinct species (1/12)
www.science.org/doi/10.1126/...
www.science.org
December 4, 2025 at 7:27 PM
I second this!
Very nearly done on a long review of this spectacular book, King Tyrant by @markwitton.bsky.social, published by @princetonupress.bsky.social Cannot recommend it enough, buy it now! #dinosaurs #books
December 3, 2025 at 3:01 PM
I could hear the bones in the wrist cracking.
December 3, 2025 at 2:45 PM
Reposted by Michael Deak
The final, formatted version of the Zanno & @jgn-paleo.bsky.social Nanotyrannus paper is out:

Zanno, L.E., Napoli, J.G. Nanotyrannus and Tyrannosaurus coexisted at the close of the Cretaceous. Nature (2025). doi.org/10.1038/s415...
Nanotyrannus and Tyrannosaurus coexisted at the close of the Cretaceous - Nature
A well-preserved skeleton of a nearly mature tyrannosaur from the Hell Creek Formation in Montana, USA supports the existence of a second Nanotyrannus species, Nanotyrannus lethaeus sp. nov., and vali...
doi.org
December 3, 2025 at 1:33 PM
Reposted by Michael Deak
This image is a recreation from the Late Pleistocene when this meme format was last relevant.
#PrehistoricPlanet #IceAge #coproliteposting
December 2, 2025 at 11:14 PM
Our findings brought to life: Different climates, different integument, all sloths 🦥. #PrehistoricPlanetlceAge
November 29, 2025 at 6:47 PM
But those are my big stand out segments of this wonderful series! Huge congrats to @tetzoo.bsky.social and everyone else who was involved, and I can't wait to see what you all cook up next!
November 28, 2025 at 1:17 AM
On another note, I really liked the juxtaposition of other megafaunal species such as elephant birds and Stellar's sea cows thriving with others in a decline in this episode. Ironic given that the former two will face extinction thousands of years in the future.
November 28, 2025 at 1:15 AM
Oh Deer: This was an intense game of cat and mouse between a #Megaloceros stag and a pack a cave hyenas. While plot armor kicked in too hardly in the end, it did give us the biggest fake out of the series with the male shedding his antlers (has this been done in paleoart?)
November 28, 2025 at 1:13 AM
Also, good on the team for not making the dire wolves white akin to Colossal's liar wolves.
November 28, 2025 at 1:01 AM
The Battle @tarpits.org: Given that La Brea holds some of the last known North American megafauna, I knew this was going to be in the last episode. Some big stakes with the female #Smilodon having to defend her cubs from #Direwolves with one paw in the tar.
November 28, 2025 at 12:59 AM
Also, can we talk about how INCREDIBLE this shot is?
November 28, 2025 at 12:53 AM