#FossilFriday The mega-tracksite at Cal Orck'o, Bolivia. A giant quarry wall criss-crossed by tracks. Until recently, this was the largest concentration of dinosaur tracks known - over 12,000!!! I visited the site last September: standing next to this giant Mesozoic monument was a dream come true.

A pretty special #FossilFriday, as today we celebrate the 100th birthday of Sir David Attenborough: an inspiration, a leader, and one of the greatest advocates for conservation for +70 years straight. The plesiosaur Attenborosaurus was named in his honour.

Happy Birthday David Attenborough! From the earliest days of television, to controller of BBC2, to bringing the wonders, beauty and fragility of the natural world to our eyes & attention - you’re a legend! www.theguardian.com/tv-and-radio...

Giant sea monsters are trending with the newly described Cretaceous "kraken"*. So for #FossilFriday, a better known super predator named after myth: Livyatan melvillei! A true terror of the Miocene oceans, I was thrilled to see original fossils and a skull cast of this killer sperm whale in Lima.

leftist publishers when you ask them about open access

happy #fossilfriday! this is lyrarapax, a radiodont from middle cambrian china. incredibly, the holotype preserves details of the animal’s nervous system, indicating that their raptorial frontal appendages were protocerebral, as was its labum (art by @ultraluther.bsky.social)

This #FossilFriday I'm moving over from giant marine reptiles to mammals! Starting with one of the biggest of them all: Perucetus collosus! First claimed to be potentially heavier than a blue whale, Perucetus had since been "downsized" drastically. It was nevertheless a mightily chonky beast >

Science is good. We should fund it.

Another reptile group from the Cretaceous seas of Colombia: the long necked elasmosaurs, Callawayasaurus and Leivanectes. Unlike their heavier, shorter necked kin, elasmosaurs specialised in smaller prey, perhaps infiltrating schools of fish using their long necks. #FossilFriday

Ancient ivory from the straight tusked elephant Palaeoloxodon antiquus that roamed #IsleofWight about 100,000 years ago when still part of the mainland. #FossilFriday

I have to admit - with so much bleak and vile things going on in the world right now (particularly here in the ME) this sudden glimpse of optimistic futurism is a pleasant reminder that humanity is not all bad. We can do good things! At least once in a while. www.nasa.gov/news-release... via @NASA

i swear this gov is a TV show. the head of intelligence got hacked and used his real name for a porn account. the head of dept of war accidentally texted war plans to a journalist. and now former head of homeland security grappling with husband's secret cross-dressing double life in anti-LGBTQ admin

Continuing with the Early Cretaceous seas of Colombia, the ecosystem's top predator: Monquirasaurus boyacensis, "El Fósil". One of the largest and most complete pliosaurs known, a separate museum had been built around this specimen, leaving it exposed but in situ #FossilFriday

Out today is our paper 'Genomic history of early dogs in Europe', in which we uncover the identity of the dogs that lived in Europe before agriculture—during the Paleolithic & Mesolithic periods: doi.org/10.1038/s415.... A thread ⬇️ (10) @biouea.bsky.social @crick.ac.uk @mpi-eva-leipzig.bsky.social

For #WorldFrogDay, the best preserved Jurassic frog in ever found, Notobatrachus from the Middle Jurassic Argentina. Several well preserved species are known, and in 2024 scientists even described the first Jurassic tadpole, attributed to this species! #FossilFriday

Another Colombian marine reptile: Kyhytysuka, a late surviving ichthyosaur from the early Cretaceous. It shows us that even right before their eventual demise, ichthyosaurs occupied top predator niches. #FossilFriday

Not the easiest #FossilFriday as war rears its head again here in the Middle east... A throwback from quieter times: The oldest known sea turtle, Desmatochelys padillai from Colombia. Despite their ancient appearance, turtles returned to the seas at a much later date than many other reptile groups

"Two charismatic marsupial species that had been thought extinct for 6,000 years are alive in rainforest in remote West Papua." Oh yeah this is super cool as both the pygmy long-fingered possum and ring-tailed glider were previously only known from fossils 🤯🧪🐀 www.theguardian.com/environment/...

scientific figures don't often make me giggle but dear lord www.nature.com/articles/s41...

For #WorldWildlifeDay , some of the best wildlife encounters I was lucky enough to have last year. Of all the myriad troubles of the world, it is an honor and a privilege to share this planet with such a great diversity of life forms. And a reminder that we should do more to protect this diversity.

Just saw the incredibly sad news that Hans-Dieter Sues has passed away. Beyond his major contributions to paleontology, in all my interactions with him over the years, he was a stellar human being. He took great joy in life and in being a paleontologist. I learned so much from him.

This is still RCI’s masterpiece. Look how they captured the weight and power of an animal totally unlike anything any of us have seen alive, in a mixed-media sculpture made of steel and old rocks. #FossilFriday

Well, #Spinosaurus is all over the news the past 24 hours. Here I'm pictured with the UoSouthhampton life-size skull reconstruction of the first species, S. aegyptiacus. The crest is largely speculative - and much less flamboyant, than in the new species. #FossilFriday

#Birdoftheday Yesterday I was lucky to connect with a dream bird: the wallcreeper! This wintering individual showed well for a good hour, meticulously scanning the cliffs for insects and spiders. Watching it climb up and fall back down each time was a pleasure. #birds #birdwatching

Forgot the tag! #worldwhaleday

One of my favourite wildlife encounters yet: dozens of southern right whales and their offspring, congregating in front of De Hoop NR, South Africa. After many decades of persecution and nearing extinction, seeing so many of this species was truly remarkable.

Featured today is one of the fossils that stumped Darwin: Toxodon! This beast proved challenging for young Darwin to identify, featuring rodent-like, ever growing teeth - albeit much bigger than any living rodent! Richard Owen, later Darwin's rival, formally described and named them. #FossilFriday

For #FossilFriday , preserved fur and osteoderms (base for underlying armor) of Darwin's ground sloth, Mylodon darwinii

We got evidence for a porcupine dinosaur before GTA 6 Zero expectations but double the amazement!

Today is #Worldwetlandday ! Some memories from my favorite wetland site I've ever seen (yet!), the Ibera marshes in northeast Argentina. a biodiversity hotspot, it is currently hosting several successful species reintroduction projects, including jaguars, giant anteaters and more!

In line with the wave of Morrison formation news this week: one of the most famous dinosaur skeletons worldwide (maybe No. 1), Diplodocus Carnegii - AKA Dippy. This cast is mounted in La Plata museum, and it fills up the room much more than the Paris or London mounts do. #FossilFriday

have you ever wanted to see dimetrodon vomit? no? well that's just too bad, because rebillard et al. have described a regurgitalite tentatively attributed to d. teutonis from early permian germany www.nature.com/articles/s41...

🦏 Animal #909 🦣 I figured it out in 5 guesses! 🟧🟨🟩🟨🟩 🔥 1 | Avg. Guesses: 7.5 metazooa.com #metazooa

breaking: xenorhinotherium patagonius files trademark infringement lawsuit against patagonia, claiming "we were here first"

Limaysaurus tesonnei from Late Cretaceous Argentina is one of the most completely known rebbachisaurids. This dorsal vertebra is part of the holotype. #FossilFriday #sauropod #dinosaur #fossil

Aucasaurus garridoi, one of the most completely known abelisaurs and a key specimen in our understanding of the group. Found among the numerous egg fossils of Auca Mahuevo #FossilFriday

wikipedia turns 25 today! the last unenshittified major website! backbone of online info! triumph of humanity! powered by urge of unpaid randos to correct each other! somehow mostly reliable! "good thing wikipedia works in practice, because it sure doesn't work in theory" - old wiki adage

For this #FossilFriday and in light of the rhabdodontid news this week, a decidedly ornithopod dinosaur from Gondwana: Talenkauen, one of the more completely known members of elasmaria. No definite ceratopsians were ever recovered in Cretaceous Gondwana (yet!), but several odd fossils were (cont>)

Out in @nature.com today, we shake up the ornithischian family tree. Remember those weird Late Cretaceous iguanodontians, the rhabdodontids? Well they're weird because they aren't iguanodontians. They're ceratopsians. Well, at least some of them are... www.nature.com/articles/s41...

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.

For the last #FossilFriday of 2025, the tail vertebra of the last diplodocid, Leinkupal laticauda. This family was very diverse in the Jurassic, and Leinkupal is the only one yet discovered from Cretaceous rocks (and Latin America) Art ©️ Jorge Antonio Gonzalez

For this #FossilFriday the giant Cenozoic boa like snake Madtsoia bai, from the Eocene Sarmiento formation of Argentina. At an estimated 9 meters or more, this was a very big snake. Species in the genus have been named before and after the K/Pg boundary. #snakes #fossil #museum #paleo

Today is my final day in Argentina (and South America), so for #FossilFriday - one of the most iconic dinosaurs of Argentina, Carnotaurus sastrei. Casts of this theropod are displayed in any major museum in the country, but the real fossils are housed here at the MACN. #dinosaur

#FossilFriday and #SciArt The maxilla of various Tyrannosaurus specimens (perhaps or not "rex") have several peculiar, and possibly diagnostic, surface features relating to their integument (skin, horn, whatnot). We begin with, and perhaps best with, AMNH 5027, the "archetypal" T. rex skull.

Non-stop rain since the morning, but yesterday there were much nicer views and weather! Iguazu falls, Argentina

Traveling through South America, I've seen many fossils big and small - so many that I should start my own #FossilFriday posts! Macrauchenia, one of the last and largest of the litopterns, a South American lineage that is totally extinct. Apparently, Macrauchenia had a remarkable nose ->

Hot off the press, too! www.haaretz.com/archaeology/...

And of course, many colleagues and friends have helped me in completing this project, but most of all my supervisors, Meirav Meiri and Nimrod Marom @nxmarom.bsky.social - who introduced me to this fantastic antelope, to their fields of research and supported me along the way 🙏🏼

I'm glad to share my M.Sc thesis about the extinct Levantine #hartebeest , now published and #openaccess ! Link following 🧵 The hartebeest is a staple antelope of eastern and southern African savannahs. However, the species had a far wider past distribution 1/13