In 2008, and subsequent collecting trips, the remains of a partial basal neornithischian were recovered from the Cenomanian Willow Tank Formation of southern Nevada. Bones identified include the proximal femora, a series of vertebrae missing neural arches, several pedal phalanges, fragments of ossified tendons, and some as yet unidentified elements. Size and shape of the femora are consistent with other known basal neornithischians of both orodromine- and thescelosaurine-grade. The round femoral head exhibits a convex anterior side but a concave posterior surface. The neck beneath the head projects proximodorsally at an obtuse angle (∼100°) from the femoral shaft. The greater trochanter sits slightly posterior to and offset from the neck of the femoral head. Anterior and lateral to the greater trochanter is a pointed lesser trochanter. The three-sided lesser trochanter bows slightly posterior toward the greater trochanter. A prominent and deep notch separates the lesser from the greater trochanter and is characteristic of thescelosaurine-grade ornithischians. This deep intertrochanteric notch is absent in the femora of orodromines. A raised but taphonomically truncated base on the posterior femoral diaphysis likely represents the remnants of a pendant fourth trochanter. The vertebrae of the Nevada basal neornithischian are similar to both thescelosaurine- and orodromine-grade morphology. The laterally biconcave vertebrae are asymmetrical in having a boss on the posteroventral end of the centrum. The centra are nearly twice as long as they are tall with the oval articular surfaces, taller than they are wide. Due to the very fragmentary nature of this specimen, parsimonious phylogenetic analysis yields statistically insignificant results. Nevertheless, a few taxonomically important characters, particularly those of the femur, support the hypothesis that this is a thescelosaurine, and a new genus and species, herein referred to as Nevadadromeus schmitti gen. et sp. nov. This would represent the earliest occurrence of thescelosaurines in the fossil record of North America as all other thescelosaurines from the continent date to the Maastrichtian. The geographic position of the Willow Tank Formation depocenter, very proximal to the Sevier highlands of the time, likely experienced some biogeographic insularity from other areas represented by contemporaneous units of western North America, e.g., Mussentuchit Member of the Cedar Mountain Formation of Utah, the Wayan Formation of Idaho, and the Blackleaf Formation of Montana.

The San Pedro Riparian National Conservation Area (SPRNCA) protects approximately 60 linear kilometers (km) of the San Pedro River within the Madrean Sky Islands region of southeastern Arizona. This cottonwood-willow (Populus fremontii-Salix gooddingii) gallery forest habitat with perennial surface flow is unique from the Chihuahuan mesquite desert and supports a wide diversity of plant and animal life. Mountain lions (Puma concolor) were hypothesized to use the SPRNCA as a temporary habitat while moving between neighboring mountain ranges. Using remote camera traps located on desert washes that drain the Huachuca Mountains, we demonstrated that mountain lions use the riparian corridor as part of their resident home range. We recorded 53 independent observations (mean of 1.47 observations per 100 trap nights) of mountain lions with at least 30 minutes between sightings during our study between September 2019 and May 2021. Mountain lions were found using riparian habitat in all seasons and photos were taken of young kittens within 0.3 km of the San Pedro River. Preferred prey species (Coue's white-tailed deer [Odocoileus virginianus couesi] and javelina [Pecari tajacu]) have been observed often within the SPRNCA. Future research should explore the connectivity and metapopulation structure of mountain lions within the SPRNCA and neighboring mountain ranges.

The red-legged seriema (Cariama cristata) is unique among extant birds in that they possess prominent recurved sickle claws on the second pedal digits which are held off the ground, outwardly similar to the claws of the extinct deinonychosaurs and basal avialans, and probably convergently evolved due to similar lifestyle/feeding habits. Thus, the way in which seriemas use their claws has the potential to shine additional light on how deinonychosaurs used theirs. Though formerly thought of as slashing weapons, it has also been hypothesized that deinonychosaurs used their claws to pin and grasp rather than slash. This newer hypothesis has been called the Raptor Prey Restraint (RPR) hypothesis. Our observations of claw use in simulated and real feeding behavior of red-legged seriemas at the Wildlife World Zoo, Aquarium, and Safari Park in Phoenix, AZ, and the Tracy Aviary and Botanical Gardens in Salt Lake City, UT, are consistent with the RPR hypothesis. The seriemas were observed using their feet, with special preference given to digit II, to pin objects/prey, which were torn at in tandem with the beak. Given the high degree of similarity between the claws of seriemas and the claws of deinonychosaurs, as well as their shared paravian ancestry and similar predatory cursorial lifestyles, it is likely that seriemas are among the best extant proxies for deinonychosaur claw use. That they use their claws in a manner so consistent with hypothesized deinonychosaur claw use is further evidence that the RPR hypothesis is most likely the best hypothesis for the function of the digit II “killing claws” of deinonychosaurs.

This paper presents a speculative hypothesis that climatic change and the integration of the lower Colorado, Salt, Verde, and Gila rivers led to the development of four of Arizona's dune fields. The Parker and Casino Dune fields have been researched prior; however, the Sedona and Painted Rock Dunes are presented here as two previously unrecognized dune fields. The structure of this paper goes through each of these dune fields to (i) review current knowledge; (ii) present new insight resulting from analyses of previous soil survey mapping work; (iii) speculate on the formation hypothesis for each dune field in more detail; and (iv) detail the sorts of additional work that would test the hypotheses. While no explicit evidence connecting river integration to Arizona dune field formation is presented here, soil data, field observations, aerial imagery, and dune field proximity to integrated river systems suggest further research should be conducted on this topic.