Vertebrate ichnology has usually been based on qualitative descriptions of specimens, from its be... more Vertebrate ichnology has usually been based on qualitative descriptions of specimens, from its beginning (e.g. Hitchcock 1836) to the most recent papers (e.g. Milàn, 2011; Lockley et al. 2012). At the same time, considerable effort has gone into illustrating footprint and trackway morphological features (e.g. Thulborn 1990). In recent years, new three-dimensional digitizing technologies such as laser-scanning and close-range photogrammetry (e.g Petti et al., 2008; Falkingham 2012) and methods (e.g. geometric morphometrics) have made possible more objective, quantitative approaches to vertebrate ichnology (Rasskin-Guttman et al. 1997; Azevedo-Rodriguez and Santos 2004). However, quantitative shape analyses need to be based on data of high quality, and comparisons are best made between tracks comparable in quality of preservation. Thus determining which footprints constitute the most reliable sample for quantitative analyses is fundamental for the progress of ichnology. We introduce here a numerical scale to quantify the quality of preservation of vertebrate footprints, based on morphological details present in the prints. As “preservation” we mean the record of morphological features which can be related to the anatomy of the trackmaker’s autopodium. Whether the diagnosable features of a footprint are due to the rheological features of the substrate or to the weathering of the lithified surface is not the aim of this scale. The numerical grades conceptually arise from theoretical assumptions about the fossil record, and also from experimental observations footprints of the extant emu (Dromaius novaehollandiae). The numerical scale is ordinal in character, reflecting progressively better preservation of morphological details and is set to be applicable bot to bipedal and quadrupedal trackmakers. Values range from 0 (the worst prints, occurring only as aligned depressions) to 3 (the best preserved prints), plus some coded letters to introduced to specify the occurrence of certain morphological or preservational features (e.g. skin impressions). The aim of this numerical scale is to provide a consistent means of assessing the preservation quality of footprints, both for future descriptions and for retroactive characterization of previously published material, thus facilitating application of new, quantitative methods of footprint shape analysis to previously described dinosaur tracks. The use of such a scale is not intended to replace qualitative descriptions of morphology, but rather to integrate it with a numerical value, resulting in improved understanding of the morphological features present in the specimens.
References Hitchcock E, 1836. American Journal of Science 29, 305-339 Milàn J, 2011, Bulletin of the Geological Society of Denmark 59, 51-59 Lockley MG, Li J, Matsukawa M, Li R, 2012.Cretaceous Research 34, 84-93 Thulborn T, 1990. Dinosaur tracks. Chapman & Hall, London Rasskin-Gutman D, Hunt G, Chapman RE, Sanz, JL, Moratalla JJ, 1997. Dinofeast International Proceedings,377-383. Azevedo-Rodriguez L, dos Santos VF, 2004. Morphometrics: applications in biology and paleontology. Springer-Verlag, Heidelberg Petti FM., Avanzini M, Belvedere M, De Gasperi M, Ferretti P, Girardi S, Remondino F, Tomasoni R, 2008. Studi Tridentini Scienze Naturali, Acta Geologica 83, 303-315 Falkingham PL, 2012. Palaeontologia Electronica 15 (1), 1T:15p
... Geosciences Faculty Publications. Title. Osteometric Approaches to Trackmaker Assignment for ... more ... Geosciences Faculty Publications. Title. Osteometric Approaches to Trackmaker Assignment for the Neward Supergroup Ichogenera Grallator, Anchisauripus, and Eubrontes. Author(s). ...
... Geosciences Faculty Publications. Title. A Speculative Look at the Paleoecology of Large Dino... more ... Geosciences Faculty Publications. Title. A Speculative Look at the Paleoecology of Large Dinosaurs of the Morrison Formation, or, Life with Camarasaurus and Allosaurus. Author(s). James O. Farlow. Document Type. Book Chapter. Publication Date. 2007. Publication Source. ...
... I thank Mike Brett-Surman, Dan Brinkman, Peter Dodson, Tom Lehman, Josue Njock Li-bii, John O... more ... I thank Mike Brett-Surman, Dan Brinkman, Peter Dodson, Tom Lehman, Josue Njock Li-bii, John Ostrom, Craig Packer, and Ron Rich-ards for data and/or discussions. Literature Cited ALEXANDER, R. McN. 1983. ... Review Sweet Talk ...
ABSTRACT Diplocraterion, a U-shaped burrow attributed to infaunal invertebrates, is normally a sh... more ABSTRACT Diplocraterion, a U-shaped burrow attributed to infaunal invertebrates, is normally a shallow-marine trace fossil and not part of a continental vertebrate ichnoassemblage. Hence, the Glen Rose Formation (Aptian-Albian) of Texas (USA) presents an opportunity to study Diplocraterion associated with a world-class dinosaur tracksite. Most Diplocraterion are in a bioclastic wackestone-packstone bed just above the Taylor Tracklayer, a significant dinosaur track horizon. Diplocraterion are consistently sized, but with variable depths; most have protrusive spreiten and northeast-southwest trends. Smaller Arenicolites co-occur with Diplocraterion, and other trace fossils include Rhizocorallium and a large theropod trackway. Based on our analysis, a sea-level rise buried the Taylor Tracklayer, with a shallow-marine carbonate mud colonised by Diplocraterion and Arenicolites tracemakers. Protrusive Diplocraterion, eroded burrow tops, Rhizocorallium, and other criteria point towards firming and net erosion of the bed caused by a stillstand. The depositional environment of the Diplocraterion bed was possibly a subtidal lagoon that covered shoreward sediments impacted by large theropods. Burrow orientations suggest bidirectional currents consistent with trends of theropod trackways, implying each were controlled by a shoreline. The results of our study demonstrate how marine invertebrate and continental vertebrate trace fossils can be used together to define fine-scale changes in former carbonate shorelines.
Vertebrate ichnology has usually been based on qualitative descriptions of specimens, from its be... more Vertebrate ichnology has usually been based on qualitative descriptions of specimens, from its beginning (e.g. Hitchcock 1836) to the most recent papers (e.g. Milàn, 2011; Lockley et al. 2012). At the same time, considerable effort has gone into illustrating footprint and trackway morphological features (e.g. Thulborn 1990). In recent years, new three-dimensional digitizing technologies such as laser-scanning and close-range photogrammetry (e.g Petti et al., 2008; Falkingham 2012) and methods (e.g. geometric morphometrics) have made possible more objective, quantitative approaches to vertebrate ichnology (Rasskin-Guttman et al. 1997; Azevedo-Rodriguez and Santos 2004). However, quantitative shape analyses need to be based on data of high quality, and comparisons are best made between tracks comparable in quality of preservation. Thus determining which footprints constitute the most reliable sample for quantitative analyses is fundamental for the progress of ichnology. We introduce here a numerical scale to quantify the quality of preservation of vertebrate footprints, based on morphological details present in the prints. As “preservation” we mean the record of morphological features which can be related to the anatomy of the trackmaker’s autopodium. Whether the diagnosable features of a footprint are due to the rheological features of the substrate or to the weathering of the lithified surface is not the aim of this scale. The numerical grades conceptually arise from theoretical assumptions about the fossil record, and also from experimental observations footprints of the extant emu (Dromaius novaehollandiae). The numerical scale is ordinal in character, reflecting progressively better preservation of morphological details and is set to be applicable bot to bipedal and quadrupedal trackmakers. Values range from 0 (the worst prints, occurring only as aligned depressions) to 3 (the best preserved prints), plus some coded letters to introduced to specify the occurrence of certain morphological or preservational features (e.g. skin impressions). The aim of this numerical scale is to provide a consistent means of assessing the preservation quality of footprints, both for future descriptions and for retroactive characterization of previously published material, thus facilitating application of new, quantitative methods of footprint shape analysis to previously described dinosaur tracks. The use of such a scale is not intended to replace qualitative descriptions of morphology, but rather to integrate it with a numerical value, resulting in improved understanding of the morphological features present in the specimens.
References Hitchcock E, 1836. American Journal of Science 29, 305-339 Milàn J, 2011, Bulletin of the Geological Society of Denmark 59, 51-59 Lockley MG, Li J, Matsukawa M, Li R, 2012.Cretaceous Research 34, 84-93 Thulborn T, 1990. Dinosaur tracks. Chapman & Hall, London Rasskin-Gutman D, Hunt G, Chapman RE, Sanz, JL, Moratalla JJ, 1997. Dinofeast International Proceedings,377-383. Azevedo-Rodriguez L, dos Santos VF, 2004. Morphometrics: applications in biology and paleontology. Springer-Verlag, Heidelberg Petti FM., Avanzini M, Belvedere M, De Gasperi M, Ferretti P, Girardi S, Remondino F, Tomasoni R, 2008. Studi Tridentini Scienze Naturali, Acta Geologica 83, 303-315 Falkingham PL, 2012. Palaeontologia Electronica 15 (1), 1T:15p
... Geosciences Faculty Publications. Title. Osteometric Approaches to Trackmaker Assignment for ... more ... Geosciences Faculty Publications. Title. Osteometric Approaches to Trackmaker Assignment for the Neward Supergroup Ichogenera Grallator, Anchisauripus, and Eubrontes. Author(s). ...
... Geosciences Faculty Publications. Title. A Speculative Look at the Paleoecology of Large Dino... more ... Geosciences Faculty Publications. Title. A Speculative Look at the Paleoecology of Large Dinosaurs of the Morrison Formation, or, Life with Camarasaurus and Allosaurus. Author(s). James O. Farlow. Document Type. Book Chapter. Publication Date. 2007. Publication Source. ...
... I thank Mike Brett-Surman, Dan Brinkman, Peter Dodson, Tom Lehman, Josue Njock Li-bii, John O... more ... I thank Mike Brett-Surman, Dan Brinkman, Peter Dodson, Tom Lehman, Josue Njock Li-bii, John Ostrom, Craig Packer, and Ron Rich-ards for data and/or discussions. Literature Cited ALEXANDER, R. McN. 1983. ... Review Sweet Talk ...
ABSTRACT Diplocraterion, a U-shaped burrow attributed to infaunal invertebrates, is normally a sh... more ABSTRACT Diplocraterion, a U-shaped burrow attributed to infaunal invertebrates, is normally a shallow-marine trace fossil and not part of a continental vertebrate ichnoassemblage. Hence, the Glen Rose Formation (Aptian-Albian) of Texas (USA) presents an opportunity to study Diplocraterion associated with a world-class dinosaur tracksite. Most Diplocraterion are in a bioclastic wackestone-packstone bed just above the Taylor Tracklayer, a significant dinosaur track horizon. Diplocraterion are consistently sized, but with variable depths; most have protrusive spreiten and northeast-southwest trends. Smaller Arenicolites co-occur with Diplocraterion, and other trace fossils include Rhizocorallium and a large theropod trackway. Based on our analysis, a sea-level rise buried the Taylor Tracklayer, with a shallow-marine carbonate mud colonised by Diplocraterion and Arenicolites tracemakers. Protrusive Diplocraterion, eroded burrow tops, Rhizocorallium, and other criteria point towards firming and net erosion of the bed caused by a stillstand. The depositional environment of the Diplocraterion bed was possibly a subtidal lagoon that covered shoreward sediments impacted by large theropods. Burrow orientations suggest bidirectional currents consistent with trends of theropod trackways, implying each were controlled by a shoreline. The results of our study demonstrate how marine invertebrate and continental vertebrate trace fossils can be used together to define fine-scale changes in former carbonate shorelines.
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We introduce here a numerical scale to quantify the quality of preservation of vertebrate footprints, based on morphological details present in the prints. As “preservation” we mean the record of morphological features which can be related to the anatomy of the trackmaker’s autopodium. Whether the diagnosable features of a footprint are due to the rheological features of the substrate or to the weathering of the lithified surface is not the aim of this scale.
The numerical grades conceptually arise from theoretical assumptions about the fossil record, and also from experimental observations footprints of the extant emu (Dromaius novaehollandiae). The numerical scale is ordinal in character, reflecting progressively better preservation of morphological details and is set to be applicable bot to bipedal and quadrupedal trackmakers. Values range from 0 (the worst prints, occurring only as aligned depressions) to 3 (the best preserved prints), plus some coded letters to introduced to specify the occurrence of certain morphological or preservational features (e.g. skin impressions).
The aim of this numerical scale is to provide a consistent means of assessing the preservation quality of footprints, both for future descriptions and for retroactive characterization of previously published material, thus facilitating application of new, quantitative methods of footprint shape analysis to previously described dinosaur tracks. The use of such a scale is not intended to replace qualitative descriptions of morphology, but rather to integrate it with a numerical value, resulting in improved understanding of the morphological features present in the specimens.
References
Hitchcock E, 1836. American Journal of Science 29, 305-339
Milàn J, 2011, Bulletin of the Geological Society of Denmark 59, 51-59
Lockley MG, Li J, Matsukawa M, Li R, 2012.Cretaceous Research 34, 84-93
Thulborn T, 1990. Dinosaur tracks. Chapman & Hall, London
Rasskin-Gutman D, Hunt G, Chapman RE, Sanz, JL, Moratalla JJ, 1997. Dinofeast International Proceedings,377-383.
Azevedo-Rodriguez L, dos Santos VF, 2004. Morphometrics: applications in biology and paleontology. Springer-Verlag, Heidelberg
Petti FM., Avanzini M, Belvedere M, De Gasperi M, Ferretti P, Girardi S, Remondino F, Tomasoni R, 2008. Studi Tridentini Scienze Naturali, Acta Geologica 83, 303-315
Falkingham PL, 2012. Palaeontologia Electronica 15 (1), 1T:15p
Papers
We introduce here a numerical scale to quantify the quality of preservation of vertebrate footprints, based on morphological details present in the prints. As “preservation” we mean the record of morphological features which can be related to the anatomy of the trackmaker’s autopodium. Whether the diagnosable features of a footprint are due to the rheological features of the substrate or to the weathering of the lithified surface is not the aim of this scale.
The numerical grades conceptually arise from theoretical assumptions about the fossil record, and also from experimental observations footprints of the extant emu (Dromaius novaehollandiae). The numerical scale is ordinal in character, reflecting progressively better preservation of morphological details and is set to be applicable bot to bipedal and quadrupedal trackmakers. Values range from 0 (the worst prints, occurring only as aligned depressions) to 3 (the best preserved prints), plus some coded letters to introduced to specify the occurrence of certain morphological or preservational features (e.g. skin impressions).
The aim of this numerical scale is to provide a consistent means of assessing the preservation quality of footprints, both for future descriptions and for retroactive characterization of previously published material, thus facilitating application of new, quantitative methods of footprint shape analysis to previously described dinosaur tracks. The use of such a scale is not intended to replace qualitative descriptions of morphology, but rather to integrate it with a numerical value, resulting in improved understanding of the morphological features present in the specimens.
References
Hitchcock E, 1836. American Journal of Science 29, 305-339
Milàn J, 2011, Bulletin of the Geological Society of Denmark 59, 51-59
Lockley MG, Li J, Matsukawa M, Li R, 2012.Cretaceous Research 34, 84-93
Thulborn T, 1990. Dinosaur tracks. Chapman & Hall, London
Rasskin-Gutman D, Hunt G, Chapman RE, Sanz, JL, Moratalla JJ, 1997. Dinofeast International Proceedings,377-383.
Azevedo-Rodriguez L, dos Santos VF, 2004. Morphometrics: applications in biology and paleontology. Springer-Verlag, Heidelberg
Petti FM., Avanzini M, Belvedere M, De Gasperi M, Ferretti P, Girardi S, Remondino F, Tomasoni R, 2008. Studi Tridentini Scienze Naturali, Acta Geologica 83, 303-315
Falkingham PL, 2012. Palaeontologia Electronica 15 (1), 1T:15p