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1. Paleomagnetism of the Cretaceous Galula Formation and implications for vertebrate evolution

   https://doi.org/10.1016/j.jafrearsci.2017.11.029  

   Widlansky, Sarah J.; Clyde, William C.; O'Connor, Patrick M.; Roberts, Eric M.; Stevens, Nancy J. (March 2018, Journal of African Earth Sciences)
2. Investigating the formation of the Cretaceous Western Interior Seaway using landscape evolution simulations

   https://doi.org/10.1130/B35653.1  

   Chang, Ching; Liu, Lijun (June 2020, GSA Bulletin)

   Abstract Transient intraplate sedimentation like the widespread Late Cretaceous Western Interior Seaway, traditionally considered a flexural foreland basin of the Sevier orogeny, is now generally accepted to be a result of dynamic topography due to the viscous force from mantle downwelling. However, the relative contributions of flexural versus dynamic subsidence are poorly understood. Furthermore, both the detailed subsidence history and the underlying physical mechanisms remain largely unconstrained. Here, we considered both Sevier orogenic loading and three different dynamic topography models that correspond to different geodynamic configurations. We used forward landscape evolution simulations to investigate the surface manifestations of these tectonic scenarios on the regional sedimentation history. We found that surface processes alone are unable to explain Western Interior Seaway sedimentation in a purely orogenic loading system, and that sedimentation increases readily inland with the additional presence of dynamic subsidence. The findings suggest that dynamic subsidence was crucial to Western Interior Seaway formation and that the dominant control on sediment distribution in the Western Interior Seaway transitioned from flexural to dynamic subsidence during 90–84 Ma, coinciding with the proposed emplacement of the conjugate Shatsky oceanic plateau. Importantly, the sedimentation records require the underlying dynamic subsidence to have been landward migratory, which implies that the underlying mechanism was the regional-scale mantle downwelling induced by the sinking Farallon flat slab underneath the westward-moving North American plate. The simulated landscape evolution also implies that prominent regional-scale Laramide uplift in the western United States should have occurred no earlier than the latest Cretaceous. 

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3. Late Cretaceous Notosuchians of the Maevarano Formation, Mahajanga Basin: An Ecomorphological Perspective

   Rakotozafy, B; Ranivoharimanana, L; Sertich, JJW; Rasoamiaramanana, A; O'Connor, PM (July 2024, Madamines)

   ABSTRACT The Maastrichtian Maevarano Formation of northwestern Madagascar represents deposition in a seasonal dry-wet system and hosts a rich assemblage of well-preserved fossil vertebrates. Notosuchian crocodyliforms, a diverse group of mesoeucrocodylians frequently found in Upper Cretaceous rocks of Gondwana, are well represented in this assemblage. The current study focuses on the four recognized notosuchians (Simosuchus clarki, Araripesuchus tsangatsangana, Miadanasuchus oblita and Mahajangasuchus insignis), examining their morphologic diversity to provide insight into the ecology of these sympatric taxa. Here, several complete and incomplete skulls were examined, with measurements of each cranial opening acquired for quantitative analysis. Digital photographs and high-resolution renderings based on CT/µCT reconstructions were utilized. The size, position, and orientation of the external nares, orbits, and choanae were characterized, with the relative position and size of temporal, suborbital, and external mandibular fenestrae noted for comparisons. The dentitions (size, shape, number of teeth) of the four notosuchians were also included in this study, allowing direct insight into feeding ecology of the four taxa. From the data and approaches used herein, morphologic differences were utilized to interpret potential roles of the different species in the Maevarano ecosystem. The four notosuchians can be divided between terrestrial and semi-aquatic habits, and within these ecologies, size and tooth shape assist in determining possible feeding ecology. Of the three primarily carnivorous taxa (Mahajangasuchus, Miadanasuchus, Araripesuchus), only Miadanasuchus and Araripesuchus overlapped ecologically as terrestrial predators. Maximum adult size differences between these two forms likely contributed to differences in prey choice, thereby permitting coexistence in the terrestrial environment. Simosuchus, the other terrestrial notosuchian, clearly differs from the others based on both skull and dental morphology and occupied a primarily herbivorous niche. Finally, Mahajangasuchus is the sole semi-aquatic notosuchian in the assemblage, sharing this habitat with representative and smaller-bodied neosuchians and other aquatic vertebrates and potentially competing with the other carnivorous forms for prey. In sum, the Maevarano Formation vertebrate assemblage can be used as a case-study for comparison with other Mesozoic assemblages with multiple crocodyliforms. 

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4. NODOSAUR TRACK (TETRAPODOSAURUS ) FROM THE EARLY CRETACEOUS SYKES MOUNTAIN FORMATION OF WYOMING

   Radermacher, Viktor J; Makovicky, Peter; Suarez, Celina A; Suarez, Marina; Allen, Matthew (October 2023, Journal of Vertebrate Paleontology, Program and Abstracts, 2023)
5. TITANOSAUR (DINOSAURIA: SAUROPODA) VERTEBRAE FROM THE UPPER CRETACEOUS LAMETA FORMATION OF WESTERN AND CENTRAL INDIA

   JEFFREY A. WILSON, DHANANJAY M. (December 2019, Contributions from the Museum of Paleontology)

   Cretaceous dinosaurs were first reported from the Indian subcontinent in the late 1800s, and titanosaur sauropod and abelisauroid theropod remains are now known from central, western, and southern parts of India and from central western Pakistan. Although dinosaur remains are abundant, associated or articulated specimens are extremely rare, and so are complex skeletal elements such as cranial bones and presacral vertebrae. The historical pattern of sampling and collecting has limited the inferences about patterns of diversity, phylogenetic affinity, and paleobiogeographic relationships of Indian dinosaurs. Here we report on three titanosaur vertebrae representing regions of the skeleton that are complex and otherwise poorly represented in the Indian record, including two anterior dorsal vertebrae pertaining to a single individual from Rahioli, in Gujarat State (western India), and an anterior caudal neural arch from Bara Simla, in Madhya Pradesh State (central India). Phylogenetic analysis places the two individuals within Titanosauria, but further resolution of their affinities is precluded by their incompleteness and that of titanosaur vertebral columns in general, lack of coding of character data for titanosaur presacral and anterior caudal vertebrae, and relatively coarse understanding of the evolutionary relationships of titanosaurs. Comparisons with contemporaneous and spatially proximal titanosaurs from Indo-Pakistan, Madagascar, and South America provide insights into their affinities. The dorsal vertebrae share close affinity with Isisaurus from India and Mendozasaurus from Argentina. Few local comparisons are available for the anterior caudal vertebra, which shares characteristics with Tengrisaurus from the Early Cretaceous of Russia. 

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