Thomas R. Holtz, Jr.'s Avatar

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; πŸ¦–πŸ¦•

3,631 Followers  |  636 Following  |  1,638 Posts  |  Joined: 14.11.2024  |  2.314

Latest posts by arctomet.bsky.social on Bluesky

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Shark fact:

Most "great" white sharks are actually mediocre. They're just extremely confident.

07.10.2025 18:50 β€” πŸ‘ 104    πŸ” 13    πŸ’¬ 0    πŸ“Œ 1
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Galeamopus πŸ¦•

07.10.2025 18:21 β€” πŸ‘ 57    πŸ” 14    πŸ’¬ 4    πŸ“Œ 1

This should be seen as authoritarian: A refusal to allow the work of oversight to be done, masquerading as a debating club when she ought to be answering questions.

07.10.2025 14:01 β€” πŸ‘ 1275    πŸ” 324    πŸ’¬ 74    πŸ“Œ 14

I will never not repost this, either

07.10.2025 13:07 β€” πŸ‘ 62    πŸ” 13    πŸ’¬ 0    πŸ“Œ 0
Did Cats Actually Domesticate Us?
YouTube video by Animalogic Did Cats Actually Domesticate Us?

youtu.be/pLkJ9ZadXnU?...

07.10.2025 13:07 β€” πŸ‘ 6    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

"Launched at a time when Argentina’s scientific community is confronting severe challenges under the administration of libertarian President Javier Milei, the project stands as a testament to resilience, aiming to democratize knowledge by showcasing science in real-time, against all odds." πŸ§ͺ

06.10.2025 23:14 β€” πŸ‘ 9    πŸ” 4    πŸ’¬ 1    πŸ“Œ 0

No corruption here, folks! Totally normal stuff the deputy director of the CIA(Michael Ellis) just demoted the acting general counsel and decided to make himself the top lawyer while still being the No. 2 in charge.

06.10.2025 21:15 β€” πŸ‘ 5555    πŸ” 1780    πŸ’¬ 134    πŸ“Œ 57
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The ecological and evolutionary consequences of systemic racism in urban environments Cities create challenging environments for many nonhuman species, and the presence of nonhumans in cities influences the health and well-being of the humans with which they share the environment. Dist...

In a 2020 #ScienceReview, researchers investigated how systematic racist practices such as residential segregation have led to an unequal distribution of β€œnature” within cities.

Learn more on #WorldHabitatDay: https://scim.ag/3KQnEir

06.10.2025 19:17 β€” πŸ‘ 49    πŸ” 16    πŸ’¬ 0    πŸ“Œ 0

"We're gonna crash some planes if you don't fund ICE."

06.10.2025 17:18 β€” πŸ‘ 8439    πŸ” 1968    πŸ’¬ 350    πŸ“Œ 69

Please do your part!

06.10.2025 17:04 β€” πŸ‘ 5    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

β€œThe Party told you to reject the evidence of your eyes and ears. It was their final, most essential command.”

― George Orwell, 1984

06.10.2025 17:56 β€” πŸ‘ 850    πŸ” 283    πŸ’¬ 39    πŸ“Œ 9

See how fast they invent some antifa nonsense to account for it.

06.10.2025 16:58 β€” πŸ‘ 7    πŸ” 2    πŸ’¬ 0    πŸ“Œ 0
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Chicago Mayor Brandon Johnson:

"Private establishments can partner with us to make it clear that private property is private property and ICE cannot enter establishments without a valid warrant ... If Congress will not check this administration, then Chicago will."

06.10.2025 17:52 β€” πŸ‘ 18354    πŸ” 5295    πŸ’¬ 316    πŸ“Œ 329
The image is an X post by Acyn (@Acyn
) from 13 hours ago, quoting Pritzker: "He's saying that Chicago is a war zone. None of that is true. They're just making this up. And then what do they do? They fire tear gas and smoke grenades, and they make it look like it's a war zone." The post includes a screenshot from CNN's "State of the Union" showing two individuals discussing, with a chyron indicating DHS officers fired at a driver who rammed their vehicle, later determined to be someone trying to storm the Presidential Palace, as the South Caucasus Coalition.

The image is an X post by Acyn (@Acyn ) from 13 hours ago, quoting Pritzker: "He's saying that Chicago is a war zone. None of that is true. They're just making this up. And then what do they do? They fire tear gas and smoke grenades, and they make it look like it's a war zone." The post includes a screenshot from CNN's "State of the Union" showing two individuals discussing, with a chyron indicating DHS officers fired at a driver who rammed their vehicle, later determined to be someone trying to storm the Presidential Palace, as the South Caucasus Coalition.

This is like planting evidence and then making an arrest.

06.10.2025 19:30 β€” πŸ‘ 15248    πŸ” 4457    πŸ’¬ 413    πŸ“Œ 144
A photo of a mudskipper hauled out of water and onto a branch. The fish is brownish in color and has unusual facial features.

A photo of a mudskipper hauled out of water and onto a branch. The fish is brownish in color and has unusual facial features.

Feel like a fish out of water? Meet the giant mudskipper! This fish needs to breathe air & spends a decent amount of time on land! Found on the muddy shores of mangroves in parts of Southeast Asia, it uses its pectoral fins to β€œwalk” across mudflats.

Photo: mysorekid, CC BY-NC-SA 4.0, iNaturalist

06.10.2025 19:35 β€” πŸ‘ 80    πŸ” 13    πŸ’¬ 2    πŸ“Œ 3
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Same.

#AlsoTiredOfWaitingForTheEPSTEIN_Files

06.10.2025 19:05 β€” πŸ‘ 40230    πŸ” 9531    πŸ’¬ 1831    πŸ“Œ 816
A Brief Explanation About Triploid Oysters | Panhandle Outdoors

It is common to for aquaculture to use triploid oysters as their stock! They have three sets of chromosomes, rather than the usual two, rendering them sterile. This means their body growth is faster, because they don't put energy into reproduction! (291) nwdistrict.ifas.ufl.edu/nat/2024/01/...

06.10.2025 18:39 β€” πŸ‘ 14    πŸ” 4    πŸ’¬ 1    πŸ“Œ 1
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The Prick-in-Chief is seriously trying to incite a Civil War hoping somebody attacks ICE so
he can declare martial law to test methods of delaying the midterms.

Massive trial balloon that is emotionally & psychologically terrorizing millions of Americans.

This is not leadership.
It’s fascism.

06.10.2025 13:52 β€” πŸ‘ 911    πŸ” 362    πŸ’¬ 68    πŸ“Œ 22
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Jamie Raskin: It's not lost on anyone that shutting the government down allows them not to swear in Adelita Grijalva, who would be the 218th signature to release the Epstein files. So, it’s convenient for them to shut the government down.
#ProudBlue #Pinks #TrumpIsUnfitForOffice

06.10.2025 13:51 β€” πŸ‘ 506    πŸ” 230    πŸ’¬ 25    πŸ“Œ 5
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Galloanseran cranial development highlights exceptions to von Baer’s laws - EvoDevo The remarkable morphological disparity of the animal kingdom is underpinned by changes in embryonic development across the tree of life; as such, deciphering evolutionary patterns of developmental divergence depends on investigations of different species across a range of comparable developmental stages. Among the most influential ideas regarding such developmental divergences are von Baer’s Laws of Development and Haeckel’s Theory of Recapitulation. Here, we assess several predictions following from these ideas at the tissue-level by comparing skull osteogenesis in representatives of the bird clade Galloanserae. We investigated high-resolution Β΅CT scans of embryonic series for four galloanseran species: chickens and quails, representing Galliformes (landfowl), and ducks and geese, representing Anseriformes (waterfowl). To compare skull osteogenesis across our taxon sample, we devised a skull-specific staging system based on ossification sequences to discretise the process into five stages. During skull osteogenesis, we found that the location of the onset of ossification within each element and the direction of ossification progression were the same in all species in our sample, implying a conserved developmental programme for induction and ossification progression across Galloanserae. Moreover, we found that the appearance of synapomorphies diagnostic of broader clades often overlapped with species-specific ones during osteogenesis. Indeed, many diagnostic features of deep clades, such as osteological synapomorphies of the phylogenetically inclusive clade Galloanserae, appear at surprisingly late stages of development. These observations fail to support several predictions of von Baer’s Laws of Development and Haeckel’s Theory of Recapitulation, instead suggesting what we term a β€˜braiding’ pattern of developmental divergence in which degrees of interspecific morphological similarity wax and wane during development as a result of the interplay between developmental constraints and phyletic variation.

Arnaout, B., Brzezinski, K., Chen, A. et al. Galloanseran cranial development highlights exceptions to von Baer’s laws. EvoDevo 16, 17 (2025). doi.org/10.1186/s132...

06.10.2025 15:16 β€” πŸ‘ 10    πŸ” 4    πŸ’¬ 0    πŸ“Œ 0
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Texas proudly invading Illinois.

It’s hard to describe the level of potential constitutional crisis here.

06.10.2025 10:34 β€” πŸ‘ 12343    πŸ” 4216    πŸ’¬ 1340    πŸ“Œ 568
Line graph time series of 2025's daily Arctic sea ice extent compared to decadal averages from the 1980s to the 2010s. The decadal averages are shown with different colored lines with purple for the 1980s, blue for the 1990s, green for the 2000s, and white for the 2010s. Thin white lines are also shown for each year from 2000 to 2024. 2025 is shown with a thick gold line. There is a long-term decreasing trend in ice extent for every day of the year shown on this graph between August and November by looking at the decadal average line positions.

Line graph time series of 2025's daily Arctic sea ice extent compared to decadal averages from the 1980s to the 2010s. The decadal averages are shown with different colored lines with purple for the 1980s, blue for the 1990s, green for the 2000s, and white for the 2010s. Thin white lines are also shown for each year from 2000 to 2024. 2025 is shown with a thick gold line. There is a long-term decreasing trend in ice extent for every day of the year shown on this graph between August and November by looking at the decadal average line positions.

Monday ice update - #Arctic sea ice extent is currently the 14th lowest on record (JAXA data) πŸ§ͺ

β€’ about 310,000 kmΒ² above the 2010s mean
β€’ about 950,000 kmΒ² below the 2000s mean
β€’ about 2,070,000 kmΒ² below the 1990s mean
β€’ about 2,720,000 kmΒ² below the 1980s mean

More: zacklabe.com/arctic-sea-i...

06.10.2025 12:48 β€” πŸ‘ 53    πŸ” 14    πŸ’¬ 3    πŸ“Œ 0
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Cranial osteology of Archaeoceratops oshimai (Ornithischia: Ceratopsia) and phylogenetic evaluation of basal Ceratopsia Archaeoceratops oshimai Dong & Azuma, 1997, is a representative early-diverging neoceratopsian dinosaur excavated from the Lower Cretaceous Xinminpu Group in the Mazongshan area of Gansu Province, ...

Cranial osteology of Archaeoceratops oshimai (Ornithischia: Ceratopsia) and phylogenetic evaluation of basal Ceratopsia: Historical Biology: Vol 0, No 0 - Get Access www.tandfonline.com/doi/full/10....

06.10.2025 12:48 β€” πŸ‘ 34    πŸ” 6    πŸ’¬ 0    πŸ“Œ 0

If you want to know the real Spinosaurus, the animal behind the myths, check out this upcoming book by @davehone.bsky.social & @markwitton.bsky.social !!

06.10.2025 09:14 β€” πŸ‘ 53    πŸ” 9    πŸ’¬ 3    πŸ“Œ 0
WALK THE MOON - One Foot (Official Video)
YouTube video by WalkTheMoonVEVO WALK THE MOON - One Foot (Official Video)

#Geol104playlist Paleozoic Tetrapoda

youtu.be/05v4nfUmBYI?...

06.10.2025 12:45 β€” πŸ‘ 6    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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Early humans dined on giant sloths and other Ice Age giants, archaeologists find What did early humans like to eat? The answer, according to a team of archaeologists in Argentina, is extinct megafauna, such as giant sloths and giant armadillos. In a study published in the journal ...

phys.org/news/2025-10...

05.10.2025 13:33 β€” πŸ‘ 84    πŸ” 7    πŸ’¬ 2    πŸ“Œ 2
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Neandertal Cold Adaptation: Technological, Anatomical, and Physiological Responses to Cold Stress in One of Our Closest Fossil Relatives Neandertals occupied western Eurasia for over 100 000 years, repeatedly enduring climates that ranged from seasonally cold to glacial. This paper reexamines the question of Neandertal cold adaptation...

Neandertal Cold Adaptation: Technological, Anatomical, and Physiological Responses to Cold Stress in One of Our Closest Fossil Relatives - Holliday - 2025 - American Journal of Human Biology - Wiley Online Library onlinelibrary.wiley.com/doi/10.1002/...

05.10.2025 13:08 β€” πŸ‘ 21    πŸ” 5    πŸ’¬ 0    πŸ“Œ 0

Full article: The Coastal Hypothesis: one possible migration route for Late Pleistocene Homo sapiens from the southern tip of Africa www.tandfonline.com/doi/full/10....

05.10.2025 12:59 β€” πŸ‘ 15    πŸ” 2    πŸ’¬ 1    πŸ“Œ 1
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Extinct megafauna dominated human subsistence in southern South America before 11,600 years ago The high position of megafauna among the hunting prey of humans in South America reinforces their central role in extinctions.

Extinct megafauna dominated human subsistence in southern South America before 11,600 years ago | Science Advances www.science.org/doi/10.1126/...

05.10.2025 12:52 β€” πŸ‘ 46    πŸ” 5    πŸ’¬ 0    πŸ“Œ 1
Redirecting

Miki Ben-Dor & Ran Barkai (2025)

The Late Quaternary Megafaunal Extinction and Upper Paleolithic Cultural Changes: A Hypothesis for Bioenergetic-Driven Human Adaptations

Quaternary Environments and Humans 100086

doi: doi.org/10.1016/j.qe...

www.sciencedirect.com/science/arti...

05.10.2025 12:52 β€” πŸ‘ 9    πŸ” 2    πŸ’¬ 0    πŸ“Œ 0

@arctomet is following 20 prominent accounts