More Like this

1. Puercosuchus traverorum n. gen. n. sp.: a new malerisaurine azendohsaurid (Archosauromorpha: Allokotosauria) from two monodominant bonebeds in the Chinle Formation (Upper Triassic, Norian) of Arizona

   https://doi.org/10.1017/jpa.2022.49  

   Marsh, Adam D.; Parker, William G.; Nesbitt, Sterling J.; Kligman, Ben T.; Stocker, Michelle R. (July 2022, Journal of Paleontology)

   Abstract Non-archosaur archosauromorphs are a paraphyletic group of diapsid reptiles that were important members of global Middle and Late Triassic continental ecosystems. Included in this group are the azendohsaurids, a clade of allokotosaurians (kuehneosaurids and Azendohsauridae + Trilophosauridae) that retain the plesiomorphic archosauromorph postcranial body plan but evolved disparate cranial features that converge on later dinosaurian anatomy, including sauropodomorph-like marginal dentition and ceratopsian-like postorbital horns. Here we describe a new malerisaurine azendohsaurid from two monodominant bonebeds in the Blue Mesa Member, Chinle Formation (Late Triassic, ca. 218–220 Ma); the first occurs at Petrified Forest National Park and preserves a minimum of eight individuals of varying sizes, and the second occurs near St. Johns, Arizona. Puercosuchus traverorum n. gen. n. sp. is a carnivorous malerisaurine that is closely related to Malerisaurus robinsonae from the Maleri Formation of India and to Malerisaurus langstoni from the Dockum Group of western Texas. Dentigerous elements from Puercosuchus traverorum n. gen. n. sp. confirm that some Late Triassic tooth morphotypes thought to represent early dinosaurs cannot be differentiated from, and likely pertain to, Puercosuchus -like malerisaurine taxa. These bonebeds from northern Arizona support the hypothesis that non-archosauriform archosauromorphs were locally diverse near the middle Norian and experienced an extinction event prior to the end-Triassic mass extinction coincidental with the Adamanian-Revueltian boundary recognized at Petrified Forest National Park. The relatively late age of this early-diverging taxon (Norian) suggests that the diversity of azendohsaurids is underrepresented in Middle and Late Triassic fossil records around the world. UUID: http://zoobank.org/e6eeefd2-a0ae-47fc-8604-9f45af8c1147 . 

   more » « less
2. DIVERSITY AND ECOLOGY OF FORAMINIFERA FROM THE GABBS FORMATION (NORIAN–RHAETIAN, NEVADA, USA)

   https://doi.org/10.1130/abs/2022AM-382024  

   Jackson, Emily; Tackett, Lydia Schiavo; Clement, Annaka; Bunker, Catherine (January 2022, Geological Society of America Abstracts with Programs)
3. A new species of the ray-finned fish Saurichthys (Actinopterygii) from the Dockum Group of Texas (Upper Triassic, Norian) highlights the late appearance of elongate jaws in neopterygians

   https://doi.org/10.1080/02724634.2025.2470026  

   Stack, Jack; Nesbitt, Sterling J; Stricklin, Maranda L; Stocker, Michelle R (September 2024, Journal of Vertebrate Paleontology)
4. Biotic extinction at the Norian/Rhaetian boundary (Upper Triassic): geochemical and isotope evidence of a previously unrecognised global event

   https://doi.org/10.46427/gold2022.11474  

   Rigo, Manuel; Onoue, Tetsuji; Sato, Honami; Tomimatsu, Yuki; Soda, Katsuhito; Godfrey, Linda; Katz, Miriam; Campbell, Hamish; Tackett, Lydia; Golding, Martyn; et al (October 2022, Goldschmidt 2022 Abstract)

   turnovers culminating in the so-called End-Triassic Extinction. We attribute onset of this interval of declining diversity to unusually high volcanic activity at the Norian/Rhaetian boundary (NRB) that may have initiated the stepwise extinctions of the Late Triassic [1]. We correlate the initiation of a rapid decline in 87Sr/86Sr and 187Os/188Os seawater values [2, 3] to a negative organic carbon isotope shift, which we attribute to volcanogenic CO2 outgassing to the ocean-atmosphere system by the Angayucham large igneous province (LIP). By studying the geochemical and isotope composition of bulk rocks from different sections located at different latitudes, sides of the Pangea continent and Hemispheres, we documented an accelerated chemical weathering due to global warming by elevated CO2, which enhanced nutrient discharge to the oceans and thus greatly increased biological productivity; higher export production and oxidation of organic matter led to oceanic dysoxia to anoxia at the NRB. Biotic consequences of these climatic and environmental changes include severe extinctions of several fossil groups, such as ammonoids, bivalves and radiolarians, as has been documented worldwide [1]. 

   more » « less
5. A NEW SUITE OF LATE TRIASSIC FISH MICROFOSSILS FROM THE NORIAN STAGE (LATE TRIASSIC) IN SOUTHLAND, NEW ZEALAND AND A MORPHOMETRIC ANALYSIS OF DIETARY PREFERENCE

   https://doi.org/10.1130/abs/2019AM-340555  

   Zierer, Deron; Tackett, Lydia S.; Clement, Annaka M. (January 2019, Geological Society of America Abstracts with Programs)