Invertebrates belonging to the largest phylum of animals, Arthropoda, with an exoskeleton, segmented bodies, and jointed appendages, including many subphyla and classes, such as insects, crustaceans, horseshoe crabs, sea spiders, centipedes, millipedes, and the extinct trilobites.
Publication (PDF format) in three parts on the biostratigraphy and lithostratigraphy of the Ibexian Series in the North American Ordovician, with sections on the southern Egan Range, Nevada and the biostratigraphy of the eastern Great Basin.
Sixty-five sampling sites, selected by a statistical design to represent lengths of perennial streams in North Dakota, were chosen to be sampled for water chemistry and mercury in fish tissue to establish unbiased baseline data.
Brief descriptions of programs of research on aquatic nonindigenous plants and animals at the Florida Integrated Science Center with links to descriptions, videos, posters, and reports on various exotic plant and animals species.
Links to USGS capabilities in paleontological analyses of fossils such as mollusks, diatoms, palynomorphs, ostracodes, calcareous nannofossils, etc. Includes descriptive information, technique, equipment, and contacts for each fossil group.
Biomonitoring projects studying the status and trends of the nation's environmental resources and programs studying amphibians and birds. Links to long-term programs, resources and references, and related links.
Life history and identification of Salvinia species, a floating, rootless tree fern and a noxious aquatic weed. Site includes posters, instructions on submitting sightings, how to subscribe to a listserv on the weed, and a bibliography.
Report (PDF format) on an evaluation of the potential environmental impacts of contaminated ground water from a metals refinery adjacent to the Missouri River in Omaha, Nebraska testing water and sediments for contaminants and toxicity.