K.Kubo

恐竜卵殻から年代を知る新手法
卵殻中の方解石に含まれる微量のウラン・鉛を測定
北米西部内陸盆地から回収された恐竜の卵化石を直接年代測定したところ、灰層を挟む高精度年代の5%以内の誤差で年代測定
ゴビ白亜紀後期の恐竜卵殻年代を初測定
地球化学データと微量元素マッピングを組み合わせた結果、非鳥類型恐竜の卵殻は堆積物との接触を通じてウラン（U）を初期に吸収していたことが示され、これは第四紀の鳥類卵の知見と一致
ニュース www.su.ac.za/en/faculties...
論文OA www.nature.com/articles/s43...

U-Pb calcite age dating of fossil eggshell as an accurate deep time geochronometer - Communications Earth & Environment Biogenic carbonate of eggshells can be used as a new geochronometer through direct calcite U-Pb dating, producing high accurate ages, as revealed by two tests on dinosaur eggs from North America and M...

Tucker, R.T., Venter, K.E., Lana, C. et al. U-Pb calcite age dating of fossil eggshell as an accurate deep time geochronometer. Commun Earth Environ 6, 872 (2025). doi.org/10.1038/s432...

違国日記、なんかいい

ニューヨーク、またちゃんと時間とって滞在したいな
アメリカ自然史博物館に、セントラルパーク

素敵なお庭ですね！カモシカ！

Powerpoint title slide of my SVP talk, showing a transparently rendered turtle shell with skull, limbs, and neck inside. The title of the talk is "Drivers and constraints in the evolution of the turtle body plan".

#2025SVP ! If you want to get an idea of the major steps of 🐢turtle🐢 evolution, come to see my talk on Friday, Nov 14, 8:30 AM, Hall 8. My student Guilherme Hermanson talks just before me (8:15). 4 years of macroevolutionary research on turtles went into our talks, covering many unpublished results.

Bittersweet to see our obituary of Mark Norell published in @currentbiology.bsky.social this week. Godspeed Mark, from Pete, Jim, and me--and the whole AMNH community.

The figure used in my News & Views commentary. I generated the CT-based rendering of the holotype skull of Nanotyrannus lancensis (CMNH 7541), based on a recent scan. The lower image was done by the Nature art department.

Here's the free link to the print version that I'm permitted to share: https://rdcu.be/eNv94. You can't download it but you can screen-capture its two pages if you really need a copy.

Our casts of (bottom) the holotype of Nanotyrannus lancensis (CMNH 7541), (middle) the newly named holotype of N. lethaeus (BMRP 2002.4.1), and (top) T. rex (AMNH 5027). We published on CMNH 7541 in 2010 (http://bit.ly/3X5nCGm).

Today's bombshell in @nature.com by Lindsay Zanno & James Napoli @jgn-paleo.bsky.social (bit.ly/4qBE6ng) shows that putative juvvy T. rex fossils actually are Nanotyrannus. I reviewed the manuscript, so Nature invited me to write the News & Views commentary. Free link: rdcu.be/eNv94 🦖

Happy Halloween 🎃

First trip for collection visits in MOR and AMNH!

James Napoli, Witmer, and Cleveland Museum of Natural History Curator of Vertebrate Paleontology Caitlin Colleary with the holotype skull of Nanotyrannus (CMNH 7541) for CT scanning (June 2023).

James Napoli with the holotype skull of Nanotyrannus (CMNH 7541) for CT scanning (June 2023).

Cleveland Museum of Natural History Curator of Vertebrate Paleontology Caitlin Colleary with the holotype skull of Nanotyrannus (CMNH 7541) for CT scanning (June 2023).

Witmer with the holotype skull of Nanotyrannus (CMNH 7541) for CT scanning (June 2023). I had this same skull on loan in my Ohio University lab for study and CT scanning for over a year and, as far as I can tell, never appeared in a photo with it. I didn't my chance this time!

We'll close out this #FossilFriday with the obvious choice of Nanotyrannus. I couldn't share this CT scanning session at the time (June 2023) but can now. @jgn-paleo.bsky.social brought the holotype Cleveland skull he had on loan, and CMNH VP curator Caitlin Colleary & I joined in the fun!

Known bones in a reconstructed skull of the herbivorous theropod dinosaur Falcarius, shown in multiple views.

New skull material of the early therizinosaurian dinosaur Falcarius: anatomypubs.onlinelibrary.wiley.com/doi/10.1002/... 🧪 (📷 @freewillie643.bsky.social & Zanno)

Ten simple rules to follow when cleaning occurrence data in palaeobiology Large datasets of fossil occurrences, often downloaded from online community-maintained databases, are a vital resource for understanding broad-scale evolutionary patterns, such as how biodiversity h...

Happy #FossilFriday! Interested in fossil data handling & building analysis-ready databases? New paper out today in Palaeontology @thepalass.bsky.social with @palaeoverse.bsky.social team led by @lewisajones.bsky.social onlinelibrary.wiley.com/doi/10.1111/...
Hope it helps! 💻📊📈🦐🦪🦣🐚🪸🦕🦖🐋🐊🐟🦑🐢🐍🦎🐦‍⬛🦂

Biomechanical simulations of hindlimb function in Alligator provide insights into postural shifts and body size evolution Locomotor simulations in alligators reveal that transitions to erect limb postures facilitate the evolution of larger body sizes.

New paper on crocodylian locomotor evolution led by Masaya Iijima, w/Richard Blob & me!
More erect hindlimb postures help extant gators support their weight (esp. at ankle), & how these mechanics constrained giant Deinosuchus to a slow walk at best!
The paper-- www.science.org/doi/10.1126/...

北海道大学
新着情報: 北海道中川町で化石を含む琥珀を大量発見～世界的にも希少な太古の陸上生態系の記録～（理学研究院　准教授　伊庭靖弘） www.hokudai.ac.jp/news/2025/10...

Martínez, R.N., Colombi, C.E., Ezcurra, M.D. et al. A Carnian theropod with unexpectedly derived features during the first dinosaur radiation. Nat Ecol Evol (2025). doi.org/10.1038/s415...

Fossilized dome of Brontotholus harmoni, a large pachycephalosaurid dinosaur from the Cretaceous Two Medicine Formation of Montana, showing its rounded, textured skull surface displayed against a dark background.

Happy #FossilFriday! Meet Brontotholus harmoni (MOR 480), a new pachycephalosaurid from the Cretaceous Two Medicine Formation of Montana. Named after former MOR Chief Preparator Bob Harmon. Bronotoholus was named this week in a @ZoolJLinnSoc paper by MSU alumnus @doublebeam and colleagues.

Excited to see this new #OA article out on turtle head vasculature, led by @seishirotada.bsky.social. It was part of Sei's PhD diss. So much fun injection, dissection, sawing, & µCT of turtles & lizards in the lab with Sei and DJ Morgan—leading to this really nice article! doi.org/10.1186/s133... 🐢

We have a new paper out! Turtle ancestors evolved a shell—but what else? We found that an unique rostral vasculature was also obtained gradually along the lineage, and that one of the earliest turtles Proganochelys likely retained a mostly ancestral state!🐢 sjpp.springeropen.com/articles/10....

#ZAVACEPHALE IS FINALLY OUT! 🥳 Our first definitive Early Cretaceous pachycephalosaur! (~15 my older than the previous oldest pachycephalosaurs) And the first hand material for the clade! I can't tell y'all how much of a pleasure it was to review this paper! ☺️

友人の作ったオリジナル手帳のリフィルを交換。一年ぐらい使い続けて、皮の質感がちょっとずつ変化してきてる。

あとは靴を新調。このこも使いまくって、ちょっとずつ育ててく

Join us! We are hiring a new #curator at the #AMNH in #Vertebrate #Zoology careers.amnh.org/postings/4600 #academicjobs #tenuretrack

Excited to be in Fukui, Japan, for the 6th International Symposium on Asian Dinosaurs #ISAD2025 which starts today. Fukui is a dinosaur town (my kind of town!), with life-size robotic dinosaurs around town! 🦖

New specimens of the arthrodire Bullerichthys fascidens Dennis and Miles 1980 show incipient site-specific osteichthyan-like tooth addition and resorption - Swiss Journal of Palaeontology The arthrodiran placoderm Bullerichthys fascidens, from the Late Devonian Gogo Formation, Western Australia, was originally described from an incomplete headshield with only the spinal and interolater...

New paper out yesterday "New specimens of the arthrodire Bullerichthys fascidens Dennis and Miles 1980 show incipient site-specific osteichthyan-like tooth addition and resorption"

Read it now in Swiss Journal of Palaeontology: sjpp.springeropen.com/articles/10....

An exciting update on the human joint side – we found that lateral patellar tracking and malalignment are correlated with progressive cartilage damage, and that the 3D metrics we've been developing to describe PF morphology can be used to quantify the risk.

journals.sagepub.com/doi/10.1177/...

Major update to Open Source photogrammetry software Meshroom Meshroom has for some time been one of my top choices for open-source or free photogrammetry software, offering a really deep amount of customization and tinkering. However, while this blog made a big splash early on reviewing all the different open-source photogrammetry software, I've found they haven't really kept up with Metashape or RealityScan, and I'm just not using them much any more.

Major update to Open Source photogrammetry software Meshroom

Meshroom has for some time been one of my top choices for open-source or free photogrammetry software, offering a really deep amount of customization and tinkering. However, while this blog made a big splash early on reviewing all the…

With a pristine skull, tiny phalanges, gastroliths, & an articulated tail, Zavacephale is the oldest & most complete pachycephalosaur ever found #fossilfriday I had the pleasure of photographing it last week, what a beauty! Congrats to the authors, read about it here: www.nature.com/articles/s41...

Shaken to hear Mark Norell passed—good friend, trusted colleague, giant in our field. Coincidentally, I got the news as I was working on my talk for the Intl. Symp. on Asian Dinosaurs in Fukui later this month. Here's my slide on Mark’s impact on Asian dinosaur science. It hurt to add 1957–2025. 😥

Letter with "American Museum of Natural History" in header. 3 December, 1991 addressed to Mr. Andy Farke, Armour, South Dakota 57313 Text of letter: Dear Andy: Thank you for the letter and drawing regarding your theory on gizzards in Coelophysis. Indeed, small rounded stones called gastroliths have been found within rib cages of prehistoric dinosaurs and their relatives. Furthermore, modern day crocodiles and chickens, close relatives of dinosaurs, ingest small stones. Based on this evidence, it is likely that the digestive system of Ceolophysis included a gizzard. Though you are far away from the American Museum, I encourage you to keep up your interest in paleontology and science. There are many good books in the library that can help you learn about fossils and how scientists develop theories from them. Furthermore, many dinosaur remains have been found in your home state of South Dakota. They include Tyrannosaurus rex, Triceratops and Anatosaurus. We hope you will get a chance to visit our museum in the future. Sincerely, Mark A. Norell Assistant Curator of Vertebrate Paleontology

When I was 10, I wrote to Mark with my ideas about dinosaur digestion. His response was encouraging, gracious, and part of what kept my interest in paleontology alive, and likely led in part to my path into education with high schoolers. Thank you, Mark. 2/2

We lost Mark Norell today. Dinosaur hunter extraordinaire. The coolest dude alive. My PhD supervisor.
Wherever you are, raise a glass of your favorite lager or single malt, as it is what Mark would want.