The late Paleozoic continental margin of western Pangea was in tectonic flux from at least the mid-Paleozoic Antler orogeny through the Late Permian–earliest Triassic Sonoma orogeny. This tectonism is registered by the periodic and apparent synchronous initiation and/or disruption of sedimentary basins and their associated paleogeographic highs along the entire length of the continental margin. The continental margin was not “passive” during the late Paleozoic, as is commonly believed. The possible tectonic drive(s) for this tectonism are problematic and include (1) terrane–continent collisions, (2) transpression and transtension along a long-lived translational margin, (3) far-field stresses related to continent–continent collision along the Appalachian–Ouachita–Marathon margins, and (4) shifts in mantle-plate interactions and resulting changes in global plate motions and intraplate stresses. Regardless of the specific tectonic driver, it must encompass the periodic and synchronous nature of these tectonic events and factor in the influence of preexisting crustal structures.

ABSTRACT Dinosaur tracks have been illustrated since they were first found. The earliest illustrations depicted dinosaur tracks as the work of mythical beings. With the advent of scientific inquiry into dinosaur tracks in the nineteenth century, natural explanations were sought for the fossil tracks. Illustrations of the period were relatively realistic but were influenced by then-current beliefs and were constrained by the artists’ skills and by what scientists considered salient. In the mid-nineteenth century, the first photographs were used for the scientific study of fossil tracks. Photography eliminated some limitations of artistic talent and showed complete specimens, not just aspects that were deemed salient. The ability to compare and name similar tracks from disparate authors and places became easier. Advances in photography, laser scanning, optical scanning and lidar, and the ability to manipulate images with computers, have enabled the modern synthesis of illustrating dinosaur tracks, which combines many types of images. With each advance and the adoption of newer technologies, the older methods have not been retired. Rather, we have continued to see new uses for old methods and an integration of illustrative styles. For Patrick. Your friendship and your vision will be so deeply missed.

Abstract The Late Campanian-aged Kaiparowits Formation (72.5–76.6 Ma) is a thick, fossiliferous fluvio-overbank–lacustrine complex deposited in south-central Utah. Host to one of the richest, most diverse Campanian terrestrial fossil records in North America, the physical environment of the Kaiparowits ecosystem, particularly the dynamics of the hydrological system, remains obscure. In 2014, an extensive bonebed was found in a conglomeratic sandstone unit of fluvial origin, known as the Rainbows and Unicorns Quarry. Isotopic compositions of serially sampled tooth enamel phosphate (δ 18 O p ) from tyrannosaur teeth were analysed to see if they held data that could clarify the palaeohydrology of the Kaiparowits Formation. To assess a greater palaeoecological context for the tyrannosaurs, the isotopic composition of their teeth was compared to other faunal elements, including the giant alligatoroid Deinosuchus , and turtles (Baenid, Gilmoremys , Neurankylus and Trionychid) from the same quarry. The δ 18 O w calculated from tyrannosaur was low, suggesting that isotopically-light, high-altitude runoff strongly influenced the local hydrology of the Kaiparowtis Formation. The seasonal change in δ 18 O of tyrannosaur drinking water ranged from −21.0 to −14.4‰ V-SMOW, while δ 18 O w calculated from turtles and crocodiles ranged between an average of −9.3 and −10.9‰, respectively. The seasonal precipitation pattern and temperature of the Kaiparowits Formation was then compared to analogue settings, such as the monsoonal climate of Hanoi, Vietnam and Cuiaba, Brazil. While similarities exist between these sites, the unique configuration of the Sevier Mountains adjacent to the nearby Western Interior Seaway provides the unique setting for a complex palaeohydrological system that results in a wide range of δ 18 O w as a result of cold seasonal precipitation at high elevation that runs off and mixes with local precipitation (−6.0 to −4.68‰) sourced from the Western Interior Seaway. This study demonstrates the importance of serial- and micro-sampling of multi-taxa comparisons for isotopic investigations of palaeohydrological systems.