Cranial elaboration, in the form of domes, horns, and bony bosses, has evolved multiple times in vertebrate history, including in non-mammalian synapsids, the extinct ancestors of mammals. The lack of similarly thickened skulls in living animals has meant that very little can be inferred about how these features developed or why they evolved. Here we use comparative bone histology to describe the microanatomy of Oudenodon, a 255-million-year-old synapsid with distinctive nasal bosses. We compared thin-sections from the thickened portions of Oudenodon to the non-thickened skull of its relative, Diictodon, in order to better understand how cranial elaboration developed in synapsids. We took thin sections from the thick nasal bosses as well as non-thickened regions of Oudenodon to capture changes in tissue microstructure. Then, we compared these thin-sections to similar regions of the skull in Diictodon, which lacks cranial elaboration. In the bone tissue of both Oudenodon and Diictodon, we observed a cancellous, spongey interior sandwiched between two layers of compact cortical bone. This pattern of bone is typical in many modern skulls but the thickness of the cancellous region in Oudenodon is strikingly thicker, even in regions away from the boss. We hypothesize that increased cranial thickness in Oudenodon is due to this middle expansion of spongey, cancellous tissue. As a result of the increased bone thickness, sutures in Oudenodon are deep, wide, and convoluted when compared to the relatively simple interdigitated sutures in Diictodon. These and other histologic comparisons with distantly related taxa allow us to interpret the growth and construction of cranial elaboration in synapsids, adding to our understanding of how these thickened skulls evolved. Future work can also explore the possible soft tissue covering of these bosses and domes, which may have been used for intraspecific display or combat. 

Drepanosauromorpha is an extinct group of reptiles known from the Middle to Late Triassic (237–212 MA). The clade currently includes seven genera (Avicranium, Dolabrosaurus, Drepanosaurus, Hypuronector, Kyrgzsaurus, Megalancosaurus, and Vallesaurus) that are known from fossils collected in Europe (Italy, UK), North America (Arizona, New Mexico, New Jersey), and Asia (Kyrgyzstan). The first described drepanosauromorph, Drepanosaurus unguicaudatus, was based on a flattened holotype preserving most of a complete skeleton. Subsequently described drepanosauromorphs display the following diagnostic features: the length of the chevrons (ventral spines below the tail vertebrae) is substantially longer than corresponding tail neural spines, the cervical (neck) vertebrae are heterocoelous (saddle-shaped articular surface), the cervical ribs are absent as distinct ossifications, and the chevrons are fused to their respective centra. In recent years, both three-dimensionally preserved partial skeletons and isolated material of drepanosauromorphs have been found across both Europe and North America. These discoveries have helped shape our understanding of the biology and diversity of drepanosauromorphs. However, comparing isolated, three dimensionally preserved specimens to the more complete, yet two dimensionally preserved articulated specimens is difficult due to differences in preservation. Here, we describe a new drepanosauromorph species from the Chinle Formation in Petrified Forest National Park, Arizona based on the left second manual ungual (claw) . Some of the characteristics that distinguish this claw from those of most drepanosauromorphs is its size. It differs significantly from all known Drepanosaurus specimens (like the Italian holotype and the Hayden Quarry Drepanosaurus) because of the ventral placement of the cotyle (articulation surface), the height of the claw, the lack of compression along the pre-axial/post-axial plane, and a furrow along the midline. This new taxon not only highlights unsuspected morphological variation within Drepanosauromorpha, but also helps sheds light on the evolutionary history of smaller-bodied reptiles within Late Triassic ecosystems.

Imidacloprid (IMI), a neonicotinoid insecticide, is being sought by shellfish growers to control burrowing shrimp (ghost shrimp, Neotropea californiensis) in Willapa Bay and Grays Harbor, Washington. The shrimp destabilize sediments resulting in poor survival and low yields of the commercially harvested Pacific oyster (Crassostrea gigas), threatening the local shellfish industry. A permit for the use of IMI has been denied by the State, Pacific County has declared an economic emergency, and the outcome of an appeal by the growers remains uncertain. We have undertaken studies to determine if un-iodized table salt may be an alternative to IMI, specifically targeting juvenile shrimp (recruits) inhabiting the upper 10-15 cm of the sediment. Studies in 2018 indicated that a 2-3-fold increase in salinity resulted in 100% mortality when juveniles were exposed in artificial seawater. In 2019, we exposed juveniles (3 replicates, 5 shrimp each) within 10 cm of native sediment to five different salt solutions to achieve sediment pore water salinities of 25 (ambient, control), 35, 50, 70, and 100 ppt. Salt solutions were prepared with native seawater, added on top of the sediment (depth = 2 cm), and allowed to percolate through the sediment column for 6 h (low tide). At 6 h, 2 cm of ambient seawater (25 ppt) were added to simulate tidal inundation and allowed to remain on the surface for 12 h (low-high + high low tide) with two subsequent drawdowns and tidal inundations at 25 ppt (total test duration = 48 h). The sediment was then sieved to remove the shrimp and determine mortality. Average survival of controls (25 ppt) was 73.3% whereas none of the shrimp exposed to elevated salinities survived. Additional tests are underway to examine different exposure scenarios. Results to date suggest table salt may be a viable and greener alternative to IMI.