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Ceratopsians and tyrannosauroids from Cretaceous of Nevada + machine learning for classifying dinosaur tracks + multituberculate tooth marks on hadrosaurid maxilla
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Ben Creisler
May 9, 2025, 12:25:25 PMMay 9
to DinosaurMa...@googlegroups.com
Ben Creisler
New papers:
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Michael Jones, Jens N. Lallensack, Ian Jarman, Peter Falkingham & Ivo Siekmann I2025)
Classification of dinosaur footprints using machine learning
Journal of Vertebrate Paleontology e2493157
doi: https://doi.org/10.1080/02724634.2025.2493157
https://www.tandfonline.com/doi/full/10.1080/02724634.2025.2493157
Free pdf:
https://www.tandfonline.com/doi/epdf/10.1080/02724634.2025.2493157
Fossilized dinosaur footprints enable us to study the behavior of individual dinosaurs as well as interactions between dinosaurs of the same or different species. There are two principal groups of three-toed dinosaurs, ornithopods and theropods. Determining if a footprint is from an ornithopod or a theropod is a challenging problem. Based on a data set of over 300 dinosaur footprints we train several machine learning models for classifying footprints as either ornithopods or theropods. The data are provided in the form of 20 landmarks for representing each footprint which are derived from images. Variable selection using logistic forward regression demonstrates that the selected landmarks are at locations that are intuitively expected to be especially informative locations, such as the top or the bottom of a footprint. Most models show good accuracy but the recall of ornithopods, of which fewer samples were contained in the data set, was generally lower than the recall of theropods. The Multi-Layer Perceptron (MLP) stands out as the model which did best at dealing with the class imbalance. Finally, we investigate which footprints were misclassified by the majority of models. We find that some misclassified samples exhibit features that are characteristic of the other class or have a compromised shape, for example, a middle toe that points to the left or the right rather than straight ahead.
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Matthew T. Carrano (2025)
First report of ceratopsians and tyrannosauroids (Dinosauria) in the Newark Canyon Formation (Lower Cretaceous) of Nevada
Journal of Paleontology (advance online publication)
DOI: https://doi.org/10.1017/jpa.2025.4
https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/first-report-of-ceratopsians-and-tyrannosauroids-dinosauria-in-the-newark-canyon-formation-lower-cretaceous-of-nevada/EBB5CD7B4B7224FC984BEE07C24C124B
This paper describes three collections of vertebrate fossils from the Lower Cretaceous Newark Canyon Formation of Eureka County, Nevada, made by the United States Geological Survey in 1961. Briefly mentioned in the prior literature, these specimens have gone unstudied for more than sixty years, until their recent transfer to the Smithsonian Institution. Re-examination of the materials reveals the first records of neoceratopsian and tyrannosauroid dinosaurs in the Newark Canyon Formation. In addition to augmenting the known vertebrate fauna from this poorly studied stratum, these occurrences provide important new data on otherwise rare taxa during a time of major faunal transition in North America.
First report of ceratopsians and tyrannosauroids (Dinosauria) in the Newark Canyon Formation (Lower Cretaceous) of Nevada
Journal of Paleontology (advance online publication)
DOI: https://doi.org/10.1017/jpa.2025.4
https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/first-report-of-ceratopsians-and-tyrannosauroids-dinosauria-in-the-newark-canyon-formation-lower-cretaceous-of-nevada/EBB5CD7B4B7224FC984BEE07C24C124B
This paper describes three collections of vertebrate fossils from the Lower Cretaceous Newark Canyon Formation of Eureka County, Nevada, made by the United States Geological Survey in 1961. Briefly mentioned in the prior literature, these specimens have gone unstudied for more than sixty years, until their recent transfer to the Smithsonian Institution. Re-examination of the materials reveals the first records of neoceratopsian and tyrannosauroid dinosaurs in the Newark Canyon Formation. In addition to augmenting the known vertebrate fauna from this poorly studied stratum, these occurrences provide important new data on otherwise rare taxa during a time of major faunal transition in North America.
===
Free pdf:
Michael Jones, Jens N. Lallensack, Ian Jarman, Peter Falkingham & Ivo Siekmann I2025)
Classification of dinosaur footprints using machine learning
Journal of Vertebrate Paleontology e2493157
doi: https://doi.org/10.1080/02724634.2025.2493157
https://www.tandfonline.com/doi/full/10.1080/02724634.2025.2493157
Free pdf:
https://www.tandfonline.com/doi/epdf/10.1080/02724634.2025.2493157
Fossilized dinosaur footprints enable us to study the behavior of individual dinosaurs as well as interactions between dinosaurs of the same or different species. There are two principal groups of three-toed dinosaurs, ornithopods and theropods. Determining if a footprint is from an ornithopod or a theropod is a challenging problem. Based on a data set of over 300 dinosaur footprints we train several machine learning models for classifying footprints as either ornithopods or theropods. The data are provided in the form of 20 landmarks for representing each footprint which are derived from images. Variable selection using logistic forward regression demonstrates that the selected landmarks are at locations that are intuitively expected to be especially informative locations, such as the top or the bottom of a footprint. Most models show good accuracy but the recall of ornithopods, of which fewer samples were contained in the data set, was generally lower than the recall of theropods. The Multi-Layer Perceptron (MLP) stands out as the model which did best at dealing with the class imbalance. Finally, we investigate which footprints were misclassified by the majority of models. We find that some misclassified samples exhibit features that are characteristic of the other class or have a compromised shape, for example, a middle toe that points to the left or the right rather than straight ahead.
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Pavel P. Skutschas, Roman. A. Bapinaev, Igor A. Parakhin, Ivan Y. Bolotsky, Yuriy L. Bolotsky & Alexander O. Averianov
Evidence of osteophagia in Mesozoic mammals: multituberculate tooth marks on a hadrosaurid maxilla from the Late Cretaceous of the Russian Far East
HIstorical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2025.2501321
https://www.tandfonline.com/doi/full/10.1080/08912963.2025.2501321
The study of bioerosional traces provides new information on the behaviour and feeding repertoire of ancient vertebrates. Here, we describe extensive bioerosional traces (tooth marks) on the maxilla of the hadrosaurid dinosaur Kundurosaurus nagornyi from the Upper Cretaceous (Maastrichtian) Kundur locality, Russian Far East (Amur Region). The tooth marks are represented by numerous linear parallel or subparallel furrows/scores with U-shaped in cross sections, smooth edges and smooth internal texture and rare pits. The most of furrows/scores are closely spaced, often overlapped, perpendicular to the longitudinal axis or morphological structures of the bone and characterised by small width (0.3–0.5 mm), significant length (up to 13 mm) and paired arrangement. Some tooth marks are organised into groups (frequently fan-shaped). The tooth marks are identified as traces of extensive gnawing by multituberculate mammals. The multituberculate tooth marks described here were inflicted during non-feeding gnawing behaviour and represent one of the oldest indisputable evidence of osteophagia in mammals. The presence of osteophagic tooth marks on the bones indicates a period of their subaerial exposure before their final burial.
HIstorical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2025.2501321
https://www.tandfonline.com/doi/full/10.1080/08912963.2025.2501321
The study of bioerosional traces provides new information on the behaviour and feeding repertoire of ancient vertebrates. Here, we describe extensive bioerosional traces (tooth marks) on the maxilla of the hadrosaurid dinosaur Kundurosaurus nagornyi from the Upper Cretaceous (Maastrichtian) Kundur locality, Russian Far East (Amur Region). The tooth marks are represented by numerous linear parallel or subparallel furrows/scores with U-shaped in cross sections, smooth edges and smooth internal texture and rare pits. The most of furrows/scores are closely spaced, often overlapped, perpendicular to the longitudinal axis or morphological structures of the bone and characterised by small width (0.3–0.5 mm), significant length (up to 13 mm) and paired arrangement. Some tooth marks are organised into groups (frequently fan-shaped). The tooth marks are identified as traces of extensive gnawing by multituberculate mammals. The multituberculate tooth marks described here were inflicted during non-feeding gnawing behaviour and represent one of the oldest indisputable evidence of osteophagia in mammals. The presence of osteophagic tooth marks on the bones indicates a period of their subaerial exposure before their final burial.
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