A methodology of theropod print replication utilising the pedal reconstruction of Australovenator and a simulated paleo-sediment

Abstract

Distinguishing the difference between theropod and ornithopod footprints has proved a difficult task due to their similarities. Herein our aim was to produce a method where a skeleton could be more closely matched to actual fossilised footprints. The reconstructed pes of the Australian Megaraptoran Australovenator wintonensis was utilised for this footprint reconstruction. It was 3-D printed in life size, molded and cast to produce a flexible theropod foot for footprint creation. The Dinosaur Stampede National Monument, Lark Quarry, Queensland, Australia was used as our case study to compare fossilised dinosaur footprints with our reconstructed theropod prints. The footprints were created in a sediment that resembled the paleo-sediments of Lark Quarry prior to being traversed by dinosaurs. Measurements of our Australovenator prints with two distinctly different print types at Lark Quarry revealed similarities with one distinct trackway which has been the center of recent debate. These footprints consist of 11 consecutive footprints and show distinct similarities in both size and proportions to our Australovenator footprints.

Hitchcock’s Leptodactyli, Penetrative Tracks, and Dinosaur Footprint Diversity

“…Hitchcock claimed that, "no sliding back of the mud, after a thick-toed animal trod upon it, would obliterate the distinct phalangeal protuberances" (1848:141). But based on our experience with both physical and simulated substrates Ellis and Gatesy, 2013;Falkingham and Gatesy, 2014;Gatesy and Falkingham, 2017) as well as on the results of published indenter experiments (Manning, 2004;Jackson et al, 2009Jackson et al, , 2010White et al, 2017), we do not find the loss of pad detail at all surprising.…”

Defossilization: A Review of 3D Printing in Experimental Paleontology

“…Additionally, the ability to alter existing taxa or create new, hypothetical forms allows the study of non-existent morphologies, optimization, and evolutionary constraint (see Porter et al, 2015). Paleontologists have 3D printed numerous vertebrate morphologies including dinosaurs, fishes, marine reptiles, and mammals (Balanoff and Rowe, 2002;Bristowe et al, 2004;Schilling et al, 2013;Mitsopoulou et al, 2015;Das et al, 2017;Muscutt et al, 2017;White et al, 2017;Clark, 2018;Grant et al, 2018;Voegele et al, 2018) as well as invertebrates like mollusks, trilobites, brachiopods, and echinoderms (Huynh et al, 2013;Pearson, 2017;Anderson et al, 2018;DiMarco et al, 2018;Garcia et al, 2018;Johnson et al, 2018;Morse et al, 2018;Peterman and Ciampaglio, 2018;Dievert et al, 2019). Designing meaningful physical models for experimentation requires thoughtful printing choices to isolate variables.…”

“…Additionally, it can be useful to combine multiple model creation methods. For example, White et al (2017) used CT data to create a model Theropod foot in Rhinoceros 5.0 ( Figure 2D). They 3D printed this foot to create a mold that was later filled with silicon to test its footprint in a simulated paleosediment.…”

“…Once mesh repairs and supports are complete, the model must be globally scaled to an appropriate size for the printing bed. In some cases, if the desired size is larger than the bed, the investigator may be tasked with printing a model in multiple parts which can later be combined (e.g., White et al, 2017). Beyond the size limitations of the printing bed, experiments may require models to be a specific size to be meaningful for the test being conducted.…”

Saurischian dinosaur tracks from the Upper Triassic of southern Queensland: possible evidence for Australia’s earliest sauropodomorph trackmaker

“…Importantly, 3D photogrammetry methods are commonly used in surface recording and are widely recognised as a standard approach in the field of dinosaur ichnology (Falkingham et al 2018;Lallensack et al 2020a;Romilio 2020c). Researchers have documented many Australian dinosaur footprints and tracksites using 3D approaches, including those from the Jurassic (Romilio et al 2020(Romilio et al , 2021Romilio 2020b) and Cretaceous (Romilio et al 2013(Romilio et al , 2017Romilio and Salisbury 2014;Salisbury et al 2017;White et al 2017;Poropat et al 2021). Absent from these 3D digital records are Australia's Triassic dinosaur trace fossils.…”