Thomas R. Holtz, Jr.
@arctomet.bsky.social
Tyrannosaur Expert; Dinosaur Paleontologist; University of Maryland Geology Faculty; Director of the College Park Scholars-Science & Global Change Program; Science Author; Cat Dad; 🦖🦕
Pinned
For the new folks, my handle refers to the arctometatarsalian condition of the foot of certain carnivorous dinosaurs (tyrannosaurids, ornithomimids, some troodontids, alvarezsaurids, and oviraptorosaurs). Arctometatarsi involve a compression of the central metatarsal (MT III) between II and IV.
Reposted by Thomas R. Holtz, Jr.
If you haven't seen them, please do.
#January6 #January6thCommitteeHearings
www.youtube.com/playlist?lis...
#January6 #January6thCommitteeHearings
www.youtube.com/playlist?lis...
Jan. 6 Committee Full Hearings - YouTube
The House committee investigating the deadly Jan. 6, 2021, attack on the U.S. Capitol is presenting new evidence about what happened the day of the insurrect...
www.youtube.com
January 6, 2026 at 11:10 PM
If you haven't seen them, please do.
#January6 #January6thCommitteeHearings
www.youtube.com/playlist?lis...
#January6 #January6thCommitteeHearings
www.youtube.com/playlist?lis...
Reposted by Thomas R. Holtz, Jr.
Perfect example fresh off the digital presses from Peter Greene on how even the "positive" AI integration is turning students into spectators, rather than asking them to be participants. It shouldn't be hard to see how misguided this is. curmudgucation.substack.com/p/ai-student...
January 6, 2026 at 10:46 PM
Perfect example fresh off the digital presses from Peter Greene on how even the "positive" AI integration is turning students into spectators, rather than asking them to be participants. It shouldn't be hard to see how misguided this is. curmudgucation.substack.com/p/ai-student...
Reposted by Thomas R. Holtz, Jr.
This is what living in the year 2026 should look like this is the coolest shit I’ve ever seen
A hacker known as Martha Root broke in and deleted three white supremacists websites at the end of a talk during the annual hacker conference Chaos Communication Congress in Germany.
Hacktivist deletes white supremacist websites live on stage during hacker conference | TechCrunch
A hacker known as Martha Root broke in and deleted three white supremacists websites at the end of a talk during the annual hacker conference Chaos Communication Congress in Germany.
techcrunch.com
January 5, 2026 at 8:06 PM
This is what living in the year 2026 should look like this is the coolest shit I’ve ever seen
Reposted by Thomas R. Holtz, Jr.
Welcome to the American petrostate
By Michael E. Mann | Nov 7, 2024
@BulletinAtomic
The U.S. is now a failed Democratic state. With the reelection of Donald Trump..the U.S. is now poised to become an authoritarian state ruled by plutocrats & fossil fuel interests.
thebulletin.org/2024/11/welc...
By Michael E. Mann | Nov 7, 2024
@BulletinAtomic
The U.S. is now a failed Democratic state. With the reelection of Donald Trump..the U.S. is now poised to become an authoritarian state ruled by plutocrats & fossil fuel interests.
thebulletin.org/2024/11/welc...
Welcome to the American petrostate
I’ve long said that the obstacles to stabilizing warming below catastrophic levels aren’t physical or technological; they are entirely political in nature, and political obstacles can be overcome. But...
thebulletin.org
January 5, 2026 at 4:49 AM
Welcome to the American petrostate
By Michael E. Mann | Nov 7, 2024
@BulletinAtomic
The U.S. is now a failed Democratic state. With the reelection of Donald Trump..the U.S. is now poised to become an authoritarian state ruled by plutocrats & fossil fuel interests.
thebulletin.org/2024/11/welc...
By Michael E. Mann | Nov 7, 2024
@BulletinAtomic
The U.S. is now a failed Democratic state. With the reelection of Donald Trump..the U.S. is now poised to become an authoritarian state ruled by plutocrats & fossil fuel interests.
thebulletin.org/2024/11/welc...
Reposted by Thomas R. Holtz, Jr.
The Corporation for Public Broadcasting has been dissolved, ending its 58 years as the primary funder for PBS, NPR and local TV and radio stations
Corporation For Public Broadcasting Is Dissolved After 58 Years Of Service
www.huffpost.com
January 5, 2026 at 8:00 PM
The Corporation for Public Broadcasting has been dissolved, ending its 58 years as the primary funder for PBS, NPR and local TV and radio stations
Reposted by Thomas R. Holtz, Jr.
In all the craziness since the attack on Venezuela, it’s easy to lose sight of some basic international laws and principles (not to mention our Constitution and the War Powers Act) that Trump has now trashed. I lay them out to build a common foundation to argue from, in today’s piece.
January 5, 2026 at 5:54 PM
In all the craziness since the attack on Venezuela, it’s easy to lose sight of some basic international laws and principles (not to mention our Constitution and the War Powers Act) that Trump has now trashed. I lay them out to build a common foundation to argue from, in today’s piece.
Reposted by Thomas R. Holtz, Jr.
Maíllo Pérez, J., Hidalgo-Sanz, J., Moreno-Azanza, M., & Gasca-Pérez, J. M. (2025). Osteohistología e implicaciones locomotoras a partir de una tibia de dinosaurio ornitópodo de la Formación El Castellar (Cretácico Inferior, Teruel). Geogaceta, 78, 71–74. doi.org/10.55407/geo...
Osteohistología e implicaciones locomotoras a partir de una tibia de dinosaurio ornitópodo de la Formación El Castellar (Cretácico Inferior, Teruel) | Geogaceta
Cerda, I., Pereyra, M., Garrone, M., Ponce, D., Navarro, T., González, R., Militellio, M., Luna, C. y Jannello, J. (2020). Publicación Electrónica de la Asociación Paleontológica Argentina, 20 (1): 15-28.
doi.org
January 4, 2026 at 1:23 PM
Maíllo Pérez, J., Hidalgo-Sanz, J., Moreno-Azanza, M., & Gasca-Pérez, J. M. (2025). Osteohistología e implicaciones locomotoras a partir de una tibia de dinosaurio ornitópodo de la Formación El Castellar (Cretácico Inferior, Teruel). Geogaceta, 78, 71–74. doi.org/10.55407/geo...
B.S. Singer et al. (2025)
Radioisotopic age, osmium isotopes, and global correlation of the Albian-Cenomanian boundary
GSA Bulletin (advance online publication)
doi: doi.org/10.1130/B385...
pubs.geoscienceworld.org/gsa/gsabulle...
Radioisotopic age, osmium isotopes, and global correlation of the Albian-Cenomanian boundary
GSA Bulletin (advance online publication)
doi: doi.org/10.1130/B385...
pubs.geoscienceworld.org/gsa/gsabulle...
Radioisotopic age, osmium isotopes, and global correlation of the Albian-Cenomanian boundary | GSA Bulletin | GeoScienceWorld
doi.org
January 4, 2026 at 1:18 PM
B.S. Singer et al. (2025)
Radioisotopic age, osmium isotopes, and global correlation of the Albian-Cenomanian boundary
GSA Bulletin (advance online publication)
doi: doi.org/10.1130/B385...
pubs.geoscienceworld.org/gsa/gsabulle...
Radioisotopic age, osmium isotopes, and global correlation of the Albian-Cenomanian boundary
GSA Bulletin (advance online publication)
doi: doi.org/10.1130/B385...
pubs.geoscienceworld.org/gsa/gsabulle...
Reposted by Thomas R. Holtz, Jr.
Reply to Benito et al.: Problems in the Cretaceous evolution of the avian palatobasal joint
www.pnas.org/doi/10.1073/...
www.pnas.org/doi/10.1073/...
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
www.pnas.org
January 3, 2026 at 1:21 PM
Reply to Benito et al.: Problems in the Cretaceous evolution of the avian palatobasal joint
www.pnas.org/doi/10.1073/...
www.pnas.org/doi/10.1073/...
Reposted by Thomas R. Holtz, Jr.
#FossilFriday: The three-toed horse Miohippus, from the John Day Fossil Beds National Monument in Oregon.
January 2, 2026 at 6:48 PM
#FossilFriday: The three-toed horse Miohippus, from the John Day Fossil Beds National Monument in Oregon.
Reposted by Thomas R. Holtz, Jr.
Starting off #FossilFriday for 2026 with the catalyst of vertebrate paleontology: Megatherium, "the great beast". Among the largest sloths that ever lived, Megatherium includes several species that were once widely distributed over the plains and mountains of S. America.
January 2, 2026 at 7:01 PM
Starting off #FossilFriday for 2026 with the catalyst of vertebrate paleontology: Megatherium, "the great beast". Among the largest sloths that ever lived, Megatherium includes several species that were once widely distributed over the plains and mountains of S. America.
Reposted by Thomas R. Holtz, Jr.
The yearly round-up of #temnospondyl research from the past year for the first #FossilFriday post of the year: once again, a lot of stuff on European taxa but also a great mix of researchers involved in all sorts of interesting work!
🧵👇 (1/25ish?)
#temnospondyls #fossils #histology #anatomy
🧵👇 (1/25ish?)
#temnospondyls #fossils #histology #anatomy
January 2, 2026 at 6:46 PM
The yearly round-up of #temnospondyl research from the past year for the first #FossilFriday post of the year: once again, a lot of stuff on European taxa but also a great mix of researchers involved in all sorts of interesting work!
🧵👇 (1/25ish?)
#temnospondyls #fossils #histology #anatomy
🧵👇 (1/25ish?)
#temnospondyls #fossils #histology #anatomy
Earliest evidence of hominin bipedalism in Sahelanthropus tchadensis | Science Advances www.science.org/doi/10.1126/...
Earliest evidence of hominin bipedalism in Sahelanthropus tchadensis
Limb bones of the earliest known hominin, Sahelanthropus, are chimpanzee-like in shape but demonstrate adaptations for bipedalism.
www.science.org
January 2, 2026 at 9:10 PM
Earliest evidence of hominin bipedalism in Sahelanthropus tchadensis | Science Advances www.science.org/doi/10.1126/...
Reposted by Thomas R. Holtz, Jr.
First #FossilFriday of 2026: here's #paleoart of Dromaeosaurus atop a half-eaten juvenile Chasmosaurus. Dromaeosaurus was no Velociraptor clone, but a relatively robust and probably hard-biting raptorial dinosaur. Painted... two years ago now, I guess, in 2024. #fossil #paleontology #dinosaur
January 2, 2026 at 3:43 PM
First #FossilFriday of 2026: here's #paleoart of Dromaeosaurus atop a half-eaten juvenile Chasmosaurus. Dromaeosaurus was no Velociraptor clone, but a relatively robust and probably hard-biting raptorial dinosaur. Painted... two years ago now, I guess, in 2024. #fossil #paleontology #dinosaur
Determination of Smilodon fatalis (Carnivora: Felidae) brain volume and its place among extant felids by use of MicroCT scans url: academic.oup.com/biolinnean/a...
Determination of Smilodon fatalis (Carnivora: Felidae) brain volume and its place among extant felids by use of MicroCT scans
ABSTRACT. After Leidy discovered Smilodon fatalis in 1869, Merriam and Stock became interested in this felid. They made the first endocast. Since then, the
academic.oup.com
January 2, 2026 at 2:27 PM
Determination of Smilodon fatalis (Carnivora: Felidae) brain volume and its place among extant felids by use of MicroCT scans url: academic.oup.com/biolinnean/a...
Schoch, R.R., Gastou, S., Steyer, JS. et al. Morphology and ontogeny of the plagiosaurid temnospondyl Plagiosternum granulosum from the Middle Triassic of Germany. PalZ (2025). doi.org/10.1007/s125...
Morphology and ontogeny of the plagiosaurid temnospondyl Plagiosternum granulosum from the Middle Triassic of Germany - PalZ
Plagiosaurids form a small but highly disparate clade of Triassic temnospondyls that are characterized by extremely flattened and wide skulls, large orbits and a knobby to pustular ornamentation. The ...
doi.org
January 2, 2026 at 2:26 PM
Schoch, R.R., Gastou, S., Steyer, JS. et al. Morphology and ontogeny of the plagiosaurid temnospondyl Plagiosternum granulosum from the Middle Triassic of Germany. PalZ (2025). doi.org/10.1007/s125...
#FossilFriday (or at least #BiologicallyMediatedSedimentaryStructureFriday) One of the North Pole Dome, Australia, Paleoarchean stromatolites
January 2, 2026 at 1:51 PM
#FossilFriday (or at least #BiologicallyMediatedSedimentaryStructureFriday) One of the North Pole Dome, Australia, Paleoarchean stromatolites
Reposted by Thomas R. Holtz, Jr.
🚨 The first preliminary analysis from the Japan Meteorological Agency highlights 2025 as the third warmest year on record globally (since at least 1891 in this data).
Additional climate rankings will be released later for other datasets.
Graph and methods by ds.data.jma.go.jp/tcc/tcc/prod...
Additional climate rankings will be released later for other datasets.
Graph and methods by ds.data.jma.go.jp/tcc/tcc/prod...
January 2, 2026 at 1:50 PM
🚨 The first preliminary analysis from the Japan Meteorological Agency highlights 2025 as the third warmest year on record globally (since at least 1891 in this data).
Additional climate rankings will be released later for other datasets.
Graph and methods by ds.data.jma.go.jp/tcc/tcc/prod...
Additional climate rankings will be released later for other datasets.
Graph and methods by ds.data.jma.go.jp/tcc/tcc/prod...
Reposted by Thomas R. Holtz, Jr.
In this in-depth interview Billie Jean Sweeney — a former editor at The New York Times — details how the paper shifted towards openly promoting anti-trans hatred, why this was directed from the very top, how some staff pushed back and the immense damage done by the NYT legitimizing bigotry.
'A directive from above': Former NYT editor lays out how the paper pushes anti-trans bigotry
In this in-depth interview, former New York Times editor Billie Jean Sweeney details how the paper shifted towards openly promoting anti-trans hatred, how some staff tried to stop it, how it's directe...
transnews.network
January 1, 2026 at 6:32 PM
In this in-depth interview Billie Jean Sweeney — a former editor at The New York Times — details how the paper shifted towards openly promoting anti-trans hatred, why this was directed from the very top, how some staff pushed back and the immense damage done by the NYT legitimizing bigotry.
Reposted by Thomas R. Holtz, Jr.
🧵Happy New Year! 2025 ended up being a decent year for marine mammal paleontology - loads of new fossil whales and dolphins, a couple of sea cow studies, but a bit light on pinnipeds and archaeocetes. Read my new blog here, and this thread for some of this year's highlights! 🧪🐬🦖
2025 in review: advances in marine mammal paleontology
It's time for the end of the year roundup - for a while I wasn't so sure that 2025 was going to have that long a list of papers, but we en...
coastalpaleo.blogspot.com
January 1, 2026 at 6:29 PM
🧵Happy New Year! 2025 ended up being a decent year for marine mammal paleontology - loads of new fossil whales and dolphins, a couple of sea cow studies, but a bit light on pinnipeds and archaeocetes. Read my new blog here, and this thread for some of this year's highlights! 🧪🐬🦖