Dinosaur footprints classification + dino tracks from Late Jurassic of Spain + vertebrate tracks from Middle Jurassic of Mexico + more
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Ben Creisler
Jul 22, 2024, 2:10:18 PMJul 22
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Ben Creisler
Some recent dinosaur and other vertebrate ichnology papers:
Andrea Guarido, Diego Castanera & Alberto Cobos (2024)
Icnitas de dinosaurios en el Jurásico Superior de La Puebla de Valverde (Teruel, España)
[Dinosaur tracks from the Late Jurassic of La Puebla de Valverde (Teruel, Spain)]
Geogaceta 75: 55-58 (in Spanish)
doi: https://doi.org/10.55407/geogaceta100859
https://sge.usal.es/archivos/geogacetas/geo75/Geo75_p_55_58.pdf
Two new dinosaur tracksites are described in La Puebla de Valverde municipality. The footprints were found isolated in situ and ex situ in siliciclastic facies included in the Villar del Arzobispo Formation (Late Jurassic). The most distinctive fact about the study area is the large diversity of tridactyl track morphotypes. Small and large ornithopod footprints, and medium and large theropod footprints have been identified. These ichnites are preserved either as concave epireliefs and convex hiporeliefs with different preservation grades. Some of them show extramorphological features (high interdigital angles, collapsed walls, missing digits) due to the substrate conditions during the registration, which complicates the ichnotaxonomic assignment. The best-preserved medium-sized theropod footprint, classified as cf. Kayentapus isp., is different to the previously identified ichnotaxa in the Maestrazgo basin. In addition, large and gracile theropod tracks are similar to Megalosauripus cf. transjuranicus and large ornithopod tracks to Iguanodontipodidae.
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Free pdf:
https://www.researchgate.net/publication/382147842_HUELLAS_DE_VERTEBRADOS_DEL_JURASICO_DE_OAXACA
The fossil record of vertebrate footprints, from the Mesozoic of Mexico, includes sites bearing the footprints of dinosaurs and mesoreptiles. Oaxaca, bears two of these sites. The age of these sites is Middle Jurassic and are located within the sedimentary sequence of the Tecocoyunca Group (ca. 165 millions of years). One of the sites is located near Santa María Xochixtlapilco (Huajuapan de León). This locality preserves the footprints of members of Rauisuchia, a group of sauropsid archosaurs that lived in the Triassic period; the footprints of these reptiles have been assigned to the ichnofamily Chirotheriidae. It is possible that a group of rauisuchids survived into the Middle Jurassic, posterior to the fragmentation of Pangea and the global extinction event at the end of the Triassic. The second site is located near the city of Tlaxiaco, at the Ñumí River, and within the sedimentary sequence of the Zorrillo-Taberna Indiferenciadas Formation. The best-preserved footprints are those of sauropod and theropod dinosaurs. One sauropod footprint was overstepped by a theropod. A fallen rock block, from an upper stratigraphic level, preserves the footprints of an ankylosaurian dinosaur; these were assigned to the ichnogenus Tetrapodosaurus and are the oldest ankylosaurian footprints known to date.
From:
Larry F. Rinehart & Spencer G. Lucas (2024)
A walking fish trace fossil from the early Permian Robledo Mountains Formation of South-Central New Mexico, USA
HIstorical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2024.2371958
https://www.tandfonline.com/doi/full/10.1080/08912963.2024.2371958
A new ichnotaxon, Ambulopisces voigti (ichnogen. et ichnosp. nov.), from the early Permian (Wolfcampian) Robledo Mountains Formation (Hueco Group) of south-central New Mexico, is described and shown to represent a fish walking on a muddy substrate. A. voigti is a compound ichnotaxon comprising alternating left and right pectoral fin impressions that show the walking behaviour plus a superimposed sinusoidal caudal fin drag that can be assigned to Undichna. The pectoral fin impressions are surrounded by expulsion rims, which show that the fins were weight-bearing; these are larger posteriorly where sediment was pushed up by the propulsive motion of the fin. The shape of the expulsion rims thus indicates the direction of travel. Propulsion was accomplished by alternately pressing the pectoral fins into the substrate and flexing the body to bring the opposing pectoral fin and the body forward. The identity of the tracemaker is uncertain, but it was a small, low-profile fish whose pectoral fins spanned only ~ 60 mm. The proximity of the pectoral fin bases to the centerline of the trace does not support a lobe-finned fish as the tracemaker.
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Free pdf:
Michael Jones, Jens N. Lallensack, Ian Jarman, Peter Falkingham & Ivo Siekmann (2024)
Classification of dinosaur footprints using machine learning
bioRxiv 2024.07.15.603597 (preprint)
doi: https://doi.org/10.1101/2024.07.15.603597
https://www.biorxiv.org/content/10.1101/2024.07.15.603597v1
Fossilised dinosaur footprints enable us to study the behaviour 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.
Classification of dinosaur footprints using machine learning
bioRxiv 2024.07.15.603597 (preprint)
doi: https://doi.org/10.1101/2024.07.15.603597
https://www.biorxiv.org/content/10.1101/2024.07.15.603597v1
Fossilised dinosaur footprints enable us to study the behaviour 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.
====
Free pdf:
Andrea Guarido, Diego Castanera & Alberto Cobos (2024)
Icnitas de dinosaurios en el Jurásico Superior de La Puebla de Valverde (Teruel, España)
[Dinosaur tracks from the Late Jurassic of La Puebla de Valverde (Teruel, Spain)]
Geogaceta 75: 55-58 (in Spanish)
doi: https://doi.org/10.55407/geogaceta100859
https://sge.usal.es/archivos/geogacetas/geo75/Geo75_p_55_58.pdf
Two new dinosaur tracksites are described in La Puebla de Valverde municipality. The footprints were found isolated in situ and ex situ in siliciclastic facies included in the Villar del Arzobispo Formation (Late Jurassic). The most distinctive fact about the study area is the large diversity of tridactyl track morphotypes. Small and large ornithopod footprints, and medium and large theropod footprints have been identified. These ichnites are preserved either as concave epireliefs and convex hiporeliefs with different preservation grades. Some of them show extramorphological features (high interdigital angles, collapsed walls, missing digits) due to the substrate conditions during the registration, which complicates the ichnotaxonomic assignment. The best-preserved medium-sized theropod footprint, classified as cf. Kayentapus isp., is different to the previously identified ichnotaxa in the Maestrazgo basin. In addition, large and gracile theropod tracks are similar to Megalosauripus cf. transjuranicus and large ornithopod tracks to Iguanodontipodidae.
===
Free pdf:
Ruben A. Rodriguez-de la Rosa (2024)
CAPÍTULO 10 Huellas de vertebrados, del Jurásico medio de Oaxaca, México
[CHAPTER 10 Vertebrate tracks from the Middle Jurassic of Oaxaca, Mexico]
in: María Patricia Velasco de León (2024) PALEOBIOTA Y GEOLOGÍA DEL JURÁSICO DEL SUR DE MÉXICO. UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO: 251-273 (in Spanish)
[CHAPTER 10 Vertebrate tracks from the Middle Jurassic of Oaxaca, Mexico]
in: María Patricia Velasco de León (2024) PALEOBIOTA Y GEOLOGÍA DEL JURÁSICO DEL SUR DE MÉXICO. UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO: 251-273 (in Spanish)
Free pdf:
https://www.researchgate.net/publication/382147842_HUELLAS_DE_VERTEBRADOS_DEL_JURASICO_DE_OAXACA
The fossil record of vertebrate footprints, from the Mesozoic of Mexico, includes sites bearing the footprints of dinosaurs and mesoreptiles. Oaxaca, bears two of these sites. The age of these sites is Middle Jurassic and are located within the sedimentary sequence of the Tecocoyunca Group (ca. 165 millions of years). One of the sites is located near Santa María Xochixtlapilco (Huajuapan de León). This locality preserves the footprints of members of Rauisuchia, a group of sauropsid archosaurs that lived in the Triassic period; the footprints of these reptiles have been assigned to the ichnofamily Chirotheriidae. It is possible that a group of rauisuchids survived into the Middle Jurassic, posterior to the fragmentation of Pangea and the global extinction event at the end of the Triassic. The second site is located near the city of Tlaxiaco, at the Ñumí River, and within the sedimentary sequence of the Zorrillo-Taberna Indiferenciadas Formation. The best-preserved footprints are those of sauropod and theropod dinosaurs. One sauropod footprint was overstepped by a theropod. A fallen rock block, from an upper stratigraphic level, preserves the footprints of an ankylosaurian dinosaur; these were assigned to the ichnogenus Tetrapodosaurus and are the oldest ankylosaurian footprints known to date.
From:
María Patricia Velasco de León (2024)
PALEOBIOTA Y GEOLOGÍA DEL JURÁSICO DEL SUR DE MÉXICO
[Paleobiota and Geology of the Jurassic of Southern Mexico]
UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO: 290 pp (in Spanish)
https://www.zaragoza.unam.mx/paleobiota-geologia-jurasico-mexico/
Free pdf:
https://www.zaragoza.unam.mx/wp-content/2023/Publicaciones/libros/cbiologia/Paleobiota_jurasico_Mexico.pdf
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PALEOBIOTA Y GEOLOGÍA DEL JURÁSICO DEL SUR DE MÉXICO
[Paleobiota and Geology of the Jurassic of Southern Mexico]
UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO: 290 pp (in Spanish)
https://www.zaragoza.unam.mx/paleobiota-geologia-jurasico-mexico/
Free pdf:
https://www.zaragoza.unam.mx/wp-content/2023/Publicaciones/libros/cbiologia/Paleobiota_jurasico_Mexico.pdf
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Also:
Ryusuke Kimitsuki, Maria Rodriguez, Corwin Sullivan, John-Paul Zonneveld, Robin Sissons, Phil R. Bell, Nicolás E. Campione, Federico Fanti & Murray K. Gingras (2024)
Enigmatic vertebrate swimming trace fossils from the Wapiti Formation, Alberta, Canada, and their implications for paleoenvironmental reconstruction
Ichnos (advance online publication)
doi: https://doi.org/10.1080/10420940.2024.2371971
https://www.tandfonline.com/doi/full/10.1080/10420940.2024.2371971
Vertebrate ichnofossil research, when compared with invertebrate ichnological analyses, tends to put greater emphasis on identifying the trace makers rather than associating the trace fossils with animal behaviors to interpret local paleoenvironmental conditions. In 2011, several sandstone blocks bearing unusual deformational structures were collected from the Wapiti Formation exposed near Red Willow Falls, Alberta, Canada. The sandstone blocks were analyzed for their sedimentary characteristics and the morphology of the enigmatic structures in order to identify their origins and their significance for paleoenvironmental interpretation. The deformational features are interpreted to be the swim tracks of small vertebrates attempting to escape a flash flood event. The sedimentology of the sandstone suggests a rapid increase in water flow in an overbank setting, and the orientation of the traces indicate that the trace maker was initially moving against, and then moving perpendicular to, the current. This is likely the first case of a trace fossil exhibiting clear association between vertebrates and flash flood events. As such, these traces provide an excellent example of the utility of vertebrate trace fossils for assessing organism response to changing environmental conditions, thus facilitating interpretation of local geological events.
Enigmatic vertebrate swimming trace fossils from the Wapiti Formation, Alberta, Canada, and their implications for paleoenvironmental reconstruction
Ichnos (advance online publication)
doi: https://doi.org/10.1080/10420940.2024.2371971
https://www.tandfonline.com/doi/full/10.1080/10420940.2024.2371971
Vertebrate ichnofossil research, when compared with invertebrate ichnological analyses, tends to put greater emphasis on identifying the trace makers rather than associating the trace fossils with animal behaviors to interpret local paleoenvironmental conditions. In 2011, several sandstone blocks bearing unusual deformational structures were collected from the Wapiti Formation exposed near Red Willow Falls, Alberta, Canada. The sandstone blocks were analyzed for their sedimentary characteristics and the morphology of the enigmatic structures in order to identify their origins and their significance for paleoenvironmental interpretation. The deformational features are interpreted to be the swim tracks of small vertebrates attempting to escape a flash flood event. The sedimentology of the sandstone suggests a rapid increase in water flow in an overbank setting, and the orientation of the traces indicate that the trace maker was initially moving against, and then moving perpendicular to, the current. This is likely the first case of a trace fossil exhibiting clear association between vertebrates and flash flood events. As such, these traces provide an excellent example of the utility of vertebrate trace fossils for assessing organism response to changing environmental conditions, thus facilitating interpretation of local geological events.
====
Larry F. Rinehart & Spencer G. Lucas (2024)
A walking fish trace fossil from the early Permian Robledo Mountains Formation of South-Central New Mexico, USA
HIstorical Biology (advance online publication)
doi: https://doi.org/10.1080/08912963.2024.2371958
https://www.tandfonline.com/doi/full/10.1080/08912963.2024.2371958
A new ichnotaxon, Ambulopisces voigti (ichnogen. et ichnosp. nov.), from the early Permian (Wolfcampian) Robledo Mountains Formation (Hueco Group) of south-central New Mexico, is described and shown to represent a fish walking on a muddy substrate. A. voigti is a compound ichnotaxon comprising alternating left and right pectoral fin impressions that show the walking behaviour plus a superimposed sinusoidal caudal fin drag that can be assigned to Undichna. The pectoral fin impressions are surrounded by expulsion rims, which show that the fins were weight-bearing; these are larger posteriorly where sediment was pushed up by the propulsive motion of the fin. The shape of the expulsion rims thus indicates the direction of travel. Propulsion was accomplished by alternately pressing the pectoral fins into the substrate and flexing the body to bring the opposing pectoral fin and the body forward. The identity of the tracemaker is uncertain, but it was a small, low-profile fish whose pectoral fins spanned only ~ 60 mm. The proximity of the pectoral fin bases to the centerline of the trace does not support a lobe-finned fish as the tracemaker.
======
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