During Serravallian through Messinian time, marine carbonates flanked topographic highs that rimmed Neogene basins in the Western Mediterranean. Middle to upper Miocene carbonate strata in the Las Negras and Nijar areas (southeastern Spain) are 50‐150 m thick and display 50‐200 m of shelf‐to‐basin relief over 1‐2 km. Detailed studies in those areas document the effects of relative sea‐level change on sedimentation, biotic composition, and reef development. We identify three previously unrecognized, regionally correlatable depositional sequences (DS1, DS2, DS3) that occur between the underlying basement and the overlying Terminal Carbonate Complex. The lower depositional sequences (DS1, DS2) are mostly normal marine shelf (ramp) carbonates deposited on the flanks of basement highs. The basal part of DS2 locally contains some megabreccia reef blocks composed of Tarbellastraea and Porites. These blocks are the first evidence of reef growth in the area and represent a previously unrecognized period of reef development prior to the fringing reef development. The reef blocks probably formed as upslope patch reefs that were eroded and transported to distal slope locations. The upper sequence (DS3) is characterized by clinoform strata of a Porites‐dominated fringing reef complex that prograded basinward in a downstepping style with successively younger reefs forming in a topographically lower and more basinward position as a result of a net sea‐level drop. Regional correlation of Miocene shallow‐marine strata between basins in Spain and elsewhere in the western Mediterranean is complicated because basins were semi‐isolated from adjacent basins making physical correlation impossible. In addition, age‐definitive biostratigraphic markers are poorly preserved in most of the Miocene shallow‐water strata; basinal sediments that are more easily dated by microfossils do not typically interfinger with the shallow‐marine strata in outcrop. Even where datable microfossils are found, resolution of dating is poor. Our studies in the Las Negras and Nijar areas illustrate the usefulness of integrating sedimentological, geometric and biotic data with locally derived relative sea‐level (accommodation space) curves for correlation. The relative sea‐level curves for each area show remarkable similarities in shape and magnitude of sea‐level changes. These curves indicate several relative sea‐level fluctuations during Miocene carbonate deposition prior to the major sea‐level drop at the end of DS3 deposition that culminated in the exposure of the basin margin deposits and the deposition of evaporites in basinal areas during the Messinian. The depositional sequences in the Las Negras and Nijar areas may correlate with depositional sequences of similar age throughout the southern Cabo de Gata area, in Mallorca some 600 km to the northeast, and possibly in other Mediterranean locations. The widespread occurrence and possible correlation of the depositional sequences suggest regional processes such as eustacy or tectonism for their form...

Landscape-scale alterations that accompany urbanization may negatively affect the population structure of wildlife species such as freshwater turtles. Changes to nesting sites and higher mortality rates due to vehicular collisions and increased predator populations may particularly affect immature turtles and mature female turtles. We hypothesized that the proportions of adult female and immature turtles in a population will negatively correlate with landscape urbanization. As a collaborative effort of the Ecological Research as Education Network (EREN), we sampled freshwater turtle populations in 11 states across the central and eastern United States. Contrary to expectations, we found a significant positive relationship between proportions of mature female painted turtles (Chrysemys picta) and urbanization. We did not detect a relationship between urbanization and proportions of immature turtles. Urbanization may alter the thermal environment of nesting sites such that more females are produced as urbanization increases. Our approach of creating a collaborative network of scientists and students at undergraduate institutions proved valuable in terms of testing our hypothesis over a large spatial scale while also allowing students to gain hands-on experience in conservation science.

Charles D. Walcott's thin sections of the Middle Cambrian Burgess Shale of British Columbia, Canada, have yielded many specimens of the helically coiled microfossil Obruchevella delicata, as well as fragments of the cyanobacteria Marpolia and Morania, sphaeromorph acritarchs, and sclerites of the enigmatic metazoan Wiwaxia. Obruchevella of the Burgess Shale displays a spectrum of preservation styles ranging from tangled masses to well-developed helixes. All Obruchevella specimens are preserved in three dimensions, which suggests original skeletalization or early post-mortem mineralization of the organism. Morphologic analysis of Obruchevella supports an affinity with modern helical cyanobacteria. Study of all reported occurrences of Obruchevella indicates that: 1) the genus has been overly split into seventeen species; 2) no correlation between size and age of Obruchevella exists; and 3) most Obruchevella specimens are tightly coiled and have helix diameters four to six times their filament diameters.

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