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Showing results for tags 'cretaceous paleocene'.
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Around 66 Million years ago, at the end of the Maastrichtian stage of the Late Cretaceous period, an astroid struck what is now the Yucatan Peninsula of Mexico. The subsequent impact and its effects caused the KT mass extinction event. The event wiped out 75% of all life on Earth. This included all the non-avian dinosaurs and most genera of marine reptiles. The end of the event also heralded the beginning of the Cenozoic era with the Paleocene period (66.0-56.0 Million years ago), and the dawn of the age of the mammals (one of the survivors from the Cretaceous Paleocene extinction event). But what most people don't realize is that in large areas of the planet, mammals didn't immediately takeover over the top ecological niches the Non-Avian Dinosaurs left vacant. That is because many surviving reptile groups filled those voids first (albeit briefly). In many parts of the globe, The Paleocene was still the age of the reptiles. https://news.agu.org/press-release/scientists-reconstruct-ancient-impact-that-dwarfs-dinosaur-extinction-blast/ A Geologic Time Scale 2004. (2004). Nigeria: Cambridge University Press. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6842625 This was partly due to the fact that the climate of the Paleocene and Eocene was generally hotter than today, which favored Ectothermic reptiles. As a result, these reptiles quickly grew to large body sizes and many filled the voids left vacant by the extinction of the endothermic non-avian theropod dinosaurs. Here is a list of these reptiles which hopefully demonstrates the diversity of these incredible creatures during the Paleocene. Let me know if I forgot any examples. North America - Thoracosaurus neocesariensis (Gavialoidea) (Late Cretaceous-Paleocene (70.6-56.0 Million Years ago)) (Note: Thoracosaurus species could grow up to 5 meters (16 feet) in length) Kosmodraco dakotensis (Choristodera) (Paleocene (60.2-56.8 Million Years ago) (Note: Kosmodraco dakotensis could grow up to 5 meters (16 feet) in length) Kosmodraco magnicornis (Choristodera) (Paleocene (56.8-55 Million Years ago)) Champsosaurus gigas (Choristodera) (Paleocene) (Note: Champsosaurus gigas could grow up to 3 meters (9 feet) in length) Borealosuchus acutidentatus (Crocodylomorpha) (Late Cretaceous-Paleocene (66.0-63.3 Million Years ago)) Axestemys splendida (Soft-shell turtle-Trionychidae) (Late Cretaceous-Paleocene) (Note: Axestemys species could grow up to 2 meters (6 feet) in length) Axestemys montinsana (Soft-shell turtle-Trionychidae) (Late Cretaceous-Paleocene) (Note: Axestemys species could grow up to 2 meters (6 feet) in length) Adocus onerosus (turtle-Dermatemyidae) (Paleocene) (Note: Adocus species could grow up to 80 cm. (2 feet) In length) Europe - Thoracosaurus isorhynchus (Gavialoidea) (Late Cretaceous-Paleocene (70.6-56.0 Million Years ago)) (Note: Thoracosaurus species could grow up to 5 meters (16 feet) in length) South America - Cerrejonisuchus improcerus (Dyrosaurid) (Mid-Late Paleocene (60-58 Million Years ago)) Acherontisuchus guajiraensis (Dyrosaurid) (Mid-Late Paleocene (60-58 Million Years ago)) Titanoboa cerrejonensis (Boa snake-Boidae) (Mid-Late Paleocene (60-58 Million Years ago)) (Note: Titanoboa cerrejonensis could grow up to 12.8 meters (42 feet) in length) Carbonemys cofrinii (turtle-Podocnemididae) (Mid-Late Paleocene (60-58 Million Years ago)) Cerrejonemys wayuunaiki (turtle-Podocnemididae) (Mid-Late Paleocene (60-58 Million Years ago)) (Note: Cerrejonemys wayuunaiki could have grown to 1 meter (3 feet) in length)) Puentemys mushaisaensis (turtle-Bothremydidae) (Mid-Late Paleocene (60-58 Million Years ago)) (Note: Puentemys mushaisaensis could have grown to 1.51 meters (5 feet) in length)) Africa - Arambourgisuchus khouribgaensis (Dyrosaurid) (Late Paleocene (59-55 Million Years ago)) Chenanisuchus lateroculi (Dyrosaurid) (Late Cretaceous-Paleocene) (Note: Chenanisuchus lateroculi could grow up to 4.5 meters (14 feet) in length) Amananulam sanogoi (aquatic snake-Nigerophiidae) (Paleocene) Acleistochelys maliensis (turtle-Bothremydidae) (Paleocene 61.7-55.8 Million Years ago) What do you guys think?
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Could Tyrannosaurus rex have created unique cultures
Joseph Fossil posted a topic in Questions & Answers
I recently found an extremely interesting paper published in the Journal of Comparative Neurology a few days ago by Professor Suzana Herculano-Houzel of Vanderbilt University about the neuron activity within the brain of the Dinosaur Tyrannosaurus rex (Western North America, Maastrichtian Cretaceous 68.0-66.0 million years ago). The study states there is evidence (based on the size of of the Cerebrum section of its brain and the hypothetical amount of neurons (of which for the study M=Millions of Neurons) present in the brain based on its size) Tyrannosaurus rex had between 2,207-3,289M telencephalic neurons in the Cerebrum section of its brain and was capable of problem solving and even forming unique cultures. Herculano‐Houzel, S. (2023). Theropod dinosaurs had primate‐like numbers of telencephalic neurons. Journal of Comparative Neurology. https://doi.org/10.1002/cne.25453 https://onlinelibrary.wiley.com/doi/epdf/10.1002/cne.25453 Usually I'm a bit skeptical when claims like this are made, but for Tyrannosaurus rex, I'm not surprised the least bit. It's been known for quite a while the brain to body ratio of Tyrannosaurus rex is larger than that of most other dinosaurs at 1.0 kilogram in weight (with only the Raptor dinosaur Troodon likely having a larger brain to body ratio among non-avian Theropod dinosaurs). Brain Image Credit: Ashley Morhardt https://www.earthtouchnews.com/discoveries/fossils/theres-a-lot-to-learn-about-dinosaur-brains/ Larsson, H.C.E. (2001). Endocranial anatomy of Carcharodontosaurus saharicus (Theropoda: Allosauroidea) and its implications for theropod brain evolution. In: Mesozoic vertebrate life, eds Tanke D.H; Carpenter K; Skrepnick M.W. Indiana University Press, 19–33 https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.20983 The recent study A large portion of its brain was devoted to smell, but I can easily see how the size of its brain could accommodate enough neuron activity for problem solving skills and even forming cultures. What do you guys think? What do you think of the study and what would Tyrannosaurus cultures have looked like?