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; 🦖🦕
Happy Origin Day! Published OTD in 1859
November 24, 2025 at 1:34 PM
Happy Origin Day! Published OTD in 1859
#FossilFriday The walking sea cow Pezosiren at the National Museum of Natural History
November 21, 2025 at 1:26 PM
#FossilFriday The walking sea cow Pezosiren at the National Museum of Natural History
November 14, 2025 at 10:44 AM
November 12, 2025 at 11:23 PM
#FossilFriday A nest of baby Protoceratops
November 7, 2025 at 1:45 PM
#FossilFriday A nest of baby Protoceratops
Soon... Very, very soon...
November 5, 2025 at 2:25 PM
Soon... Very, very soon...
Since Prince Andrew is no longer "Prince", perhaps he can sign his name with:
c.files.bbci.co.uk/AE68/product...
c.files.bbci.co.uk/AE68/product...
November 1, 2025 at 1:27 PM
Since Prince Andrew is no longer "Prince", perhaps he can sign his name with:
c.files.bbci.co.uk/AE68/product...
c.files.bbci.co.uk/AE68/product...
October 31, 2025 at 10:44 PM
October 31, 2025 at 10:43 PM
#FossilFriday #HappyHalloween One of the most truly terrifying creatures in Earth's history: Homo sapiens. Specimen is Cro-Magnon 1.
October 31, 2025 at 12:30 PM
#FossilFriday #HappyHalloween One of the most truly terrifying creatures in Earth's history: Homo sapiens. Specimen is Cro-Magnon 1.
Not just this paper; only one "30 October" paper has been posted so far:
October 30, 2025 at 6:01 PM
Not just this paper; only one "30 October" paper has been posted so far:
Nature: seriously? Still?
October 30, 2025 at 5:29 PM
Nature: seriously? Still?
#FossilFriday The immense titanosaur Patagotitan at the @amnh.org
October 24, 2025 at 12:33 PM
#FossilFriday The immense titanosaur Patagotitan at the @amnh.org
So it's #InternationalSlothDay, so here is a Paramylodon from Big Bone Luck
October 20, 2025 at 8:31 PM
So it's #InternationalSlothDay, so here is a Paramylodon from Big Bone Luck
#FossilFriday The skull of Ankylosaurus magniventris AMNH 5214 @amnh.org
October 10, 2025 at 12:32 PM
#FossilFriday The skull of Ankylosaurus magniventris AMNH 5214 @amnh.org
Happy 120th Nameday, Tyrannosaurus rex and Albertosaurus sarcophagus!
October 4, 2025 at 7:32 PM
Happy 120th Nameday, Tyrannosaurus rex and Albertosaurus sarcophagus!
For #FossilFriday, in honor of the 120th naming of both species (tomorrow), the type specimens of Tyrannosaurus rex (at the Carnegie Museum) and Albertosaurus sarcophagus (@museumofnature)
October 3, 2025 at 12:29 PM
For #FossilFriday, in honor of the 120th naming of both species (tomorrow), the type specimens of Tyrannosaurus rex (at the Carnegie Museum) and Albertosaurus sarcophagus (@museumofnature)
We stand with the defender of Oregon, the @portlandsleestak.bsky.social
September 28, 2025 at 1:34 PM
We stand with the defender of Oregon, the @portlandsleestak.bsky.social
Well, it really depends on the species. Some (H. floresiensis, the australopithicines, etc.) are really far small in terms of brain size.
(For moderns they only show averages for female (R) and male (B): it would be better to have shown the full range of variation of H. sapiens for this figure).
(For moderns they only show averages for female (R) and male (B): it would be better to have shown the full range of variation of H. sapiens for this figure).
September 27, 2025 at 6:35 PM
Well, it really depends on the species. Some (H. floresiensis, the australopithicines, etc.) are really far small in terms of brain size.
(For moderns they only show averages for female (R) and male (B): it would be better to have shown the full range of variation of H. sapiens for this figure).
(For moderns they only show averages for female (R) and male (B): it would be better to have shown the full range of variation of H. sapiens for this figure).
And here is a modern human vs. Denisovan skull, to scale. Like Neanderthals, the average Denisovan seems to have had a greater cranial capacity than the average modern human, but there is still great overlap in the ranges of both.
September 26, 2025 at 7:00 PM
And here is a modern human vs. Denisovan skull, to scale. Like Neanderthals, the average Denisovan seems to have had a greater cranial capacity than the average modern human, but there is still great overlap in the ranges of both.
Neanderthal vs modern human skeletons, to scale
September 26, 2025 at 6:57 PM
Neanderthal vs modern human skeletons, to scale