The role of networks to overcome large-scale challenges in tomography : the non-clinical tomography users research network

Our ability to visualize and quantify the internal structures of objects via computed tomography (CT) has fundamentally transformed science. As tomographic tools have become more broadly accessible, researchers across diverse disciplines have embraced the ability to investigate the 3D structure-function relationships of an enormous array of items. Whether studying organismal biology, animal models for human health, iterative manufacturing techniques, experimental medical devices, engineering structures, geological and planetary samples, prehistoric artifacts, or fossilized organisms, computed tomography has led to extensive methodological and basic sciences advances and is now a core element in science, technology, engineering, and mathematics (STEM) research and outreach toolkits. Tomorrow's scientific progress is built upon today's innovations. In our data-rich world, this requires access not only to publications but also to supporting data. Reliance on proprietary technologies, combined with the varied objectives of diverse research groups, has resulted in a fragmented tomography-imaging landscape, one that is functional at the individual lab level yet lacks the standardization needed to support efficient and equitable exchange and reuse of data. Developing standards and pipelines for the creation of new and future data, which can also be applied to existing datasets is a challenge that becomes increasingly difficult as the amount and diversity of legacy data grows. Global networks of CT users have proved an effective approach to addressing this kind of multifaceted challenge across a range of fields. Here we describe ongoing efforts to address barriers to recently proposed FAIR (Findability, Accessibility, Interoperability, Reuse) and open science principles by assembling interested parties from research and education communities, industry, publishers, and data repositories to approach these issues jointly in a focused, efficient, and practical way. By outlining the benefits of networks, generally, and drawing on examples from efforts by the Non-Clinical Tomography Users Research Network (NoCTURN), specifically, we illustrate how standardization of data and metadata for reuse can foster interdisciplinary collaborations and create new opportunities for future-looking, large-scale data initiatives

Diversity and evolution of the sauropsid trigeminal sensory system

[EMBARGOED UNTIL 6/1/2023] Understanding the evolution of sensory perception is essential in explaining organismal behavior. Organisms using environmental stimuli to navigate their environments, avoid predation, capture prey, and find a mate, have a selective advantage. One player in organismal fitness is how and how well organisms perceive, interpret, and react to signals from their environments. Perceptions are the organized properties of physical stimuli from the environment and are modulated by the nervous system. Several key innovations in early vertebrate evolution, such as ectodermal placodes and neural crest cells, enhanced the nervous system and increased the range and types of stimuli organisms could perceive. The new body plan resulting from these innovations included a cranium capable of respiration, feeding, and information acquisition via numerous sensory organs and a segmental series of pharyngeal arches. The first pharyngeal arch includes the fifth cranial nerve, the trigeminal nerve (CN V), and its associated vasculature and is the primary somatosensory nerve of the vertebrate head. The trigeminal nerve mediates sensory perception in the first pharyngeal arch as the arch engages in feeding behavior. The trigeminal system, though conserved in general form, is diverse across vertebrates, particularly sauropsids, which have evolved extreme forms of cranial somatosensation as in probe-feeding birds, infrared-sensing pit vipers, and touch-sensitive crocodilians. It remains to be understood how these adaptations for cranial sensation evolved among different clades of sauropsids, including specific lineages of lepidosaurs, crocodylians, and birds. Previous research has used osteological structures to predict nervous tissue anatomy in small ranges of extinct dinosaur and crocodylian species. However, these hypotheses require thorough testing using modern imaging, morphometrics, and phylogenetic comparative methods. Overall, we still lack consistent anatomical means of comparing relative sensation across lineages of reptiles, and the origins of extreme forms of sensation in the clade remain largely unexplored. This research identifies patterns in form, function, and evolution of the sauropsid trigeminal system. Osteological and soft tissue structures of the trigeminal system are compared in both embryonic and adult sauropsids to understand their relationship, physiology, and morphology. These data were compared to behavioral and ecological data from the literature and form-function relationships hypothesized across environments. From this knowledge, I draw conclusions on the presence of soft tissues in extinct taxa as well as their behaviors and ecologies and evolution of the system. This research will clarify the relationships between structure, function, behavior, and ecology of the extant reptilian trigeminal system to better understand evolutionary patterns of sensation.Includes bibliographical references

A new rauisuchid (Archosauria, Pseudosuchia) from the Upper Triassic (Norian) of New Mexico increases the diversity and temporal range of the clade

Rauisuchids are large (2–6 m in length), carnivorous, and quadrupedal pseudosuchian archosaurs closely related to crocodylomorphs. Though geographically widespread, fossils of this clade are relatively rare in Late Triassic assemblages. The middle Norian (∼212 Ma) Hayden Quarry of northern New Mexico, USA, in the Petrified Forest Member of the Chinle Formation, has yielded isolated postcranial elements and associated skull elements of a new species of rauisuchid. Vivaron haydeni gen. et. sp. nov. is diagnosed by the presence of two posteriorly directed prongs at the posterior end of the maxilla for articulation with the jugal. The holotype maxilla and referred elements are similar to those of the rauisuchid Postosuchus kirkpatricki from the southwestern United States, but V. haydeni shares several maxillary apomorphies (e.g., a distinct dropoff to the antorbital fossa that is not a ridge, a straight ventral margin, and a well defined dental groove) with the rauisuchid Teratosaurus suevicus from the Norian of Germany. Despite their geographic separation, this morphological evidence implies a close phylogenetic relationship between V. haydeni and T. suevicus. The morphology preserved in the new Hayden Quarry rauisuchid V. haydeni supports previously proposed and new synapomorphies for nodes within Rauisuchidae. The discovery of Vivaron haydeni reveals an increased range of morphological disparity for rauisuchids from the low-paleolatitude Chinle Formation and a clear biogeographic connection with high paleolatitude Pangea

New insights into Late Triassic dinosauromorph-bearing assemblages from Texas using apomorphy-based identifications

The Upper Triassic Dockum Group of Garza County, Texas (lower, middle, and upper Cooper Canyon Formation) captures the radiation of Triassic non-marine tetrapods by preserving a variety of Late Triassic taxa from the southwestern United States. Our understanding of the vertebrate assemblage from these strata largely comes from a single site, the Post Quarry (lower Cooper Canyon Formation), with previous research documenting a variety of temnospondyls, sphenodontians, non-archosauriform archosauromorphs, and archosauriforms including a phytosaur, three species of aetosaurs, a poposauroid, a rauisuchid, a crocodylomorph, and several dinosauromorphs. To more completely reconstruct the vertebrate assemblage of the Dockum Group of Garza County we use an apomorphy-based approach to identify morphologically similar disarticulated and fragmentary elements from a variety of localities that span the entire Cooper Canyon Formation (Norian-Rhaetian), allowing assignments from the large clade level to the species level. Many skeletal elements are incomplete yet diagnostic and are assigned to the least inclusive clade if discrete character states do not allow for an unambiguous species-level identification. We identify new specimens referable to numerous clades including Tanystropheidae, Allokotosauria + Prolacerta + Archosauriformes, Vancleavea + Litorosuchus, Phytosauria, Paracrocodylomorpha, Dinosauriformes, and Saurischia, in addition to additional species identifications of the aetosaur Scutarx deltatlyus, and the dinosauromorph Dromomeron gregorii. Our study of this material demonstrates the utility of an apomorphy-based approach in making testable and repeatable observations for identifying small, isolated fragmentary fossil tetrapod material to reconstruct a more accurate faunal hypothesis for a portion of the Late Triassic of Texas. Previous claims of the earliest dinosaurs from near the base of the Dockum Group do not pass the apomorphy-based identification test, and the question of whether the oldest known North American dinosaurs are present in the Chinle Formation or Dockum Group can be resolved by utilizing vertebrate biostratigraphic correlation. Our revision of these fossil assemblages supports the hypothesis that early diapsids, early archosauromorphs, and non-dinosaurian dinosauromorphs were more common, diverse, and widespread in low latitudes during this time than previously thought