ABsTrAcT. -We provide a first checklist and review of all recognized taxa of the world's extinct Pleistocene and Holocene (Quaternary) turtles and tortoises that existed during the early rise and global expansion of humanity, and most likely went extinct through a combination of earlier hominin (e.g., Homo erectus, H. neanderthalensis) and later human (H. sapiens) exploitation, as well as being affected by concurrent global or regional climatic and habitat changes. This checklist complements the broader listing of all modern and extant turtles and tortoises by the Turtle Taxonomy Working Group (2014). We provide a comprehensive listing of taxonomy, names, synonymies, and stratigraphic distribution of all chelonian taxa that have gone extinct from approximately the boundary between the Late Pliocene and Early Pleistocene, ca. 2.6 million years ago, up through 1500 AD, at the beginning of modern times. We also provide details on modern turtle and tortoise taxa that have gone extinct since 1500 AD. This checklist currently includes 100 fossil turtle and tortoise taxa, including 84 named and apparently distinct species, and 16 additional taxa that appear to represent additional valid species, but are only identified to genus or family. Modern extinct turtles and tortoises include 8 species, 3 subspecies, and 1 unnamed taxon, for 12 taxa. Of the extinct fossil taxa, terrestrial tortoises of the family Testudinidae (including many large-bodied island forms) are the most numerous, with 60 taxa. When the numbers for fossil tortoises are combined with the 61 modern (living and extinct) species of tortoises, of the 121 tortoise species that have existed at some point since the beginning of the Pleistocene, 69 (57.0%) have gone extinct. This likely reflects the high vulnerability of these large and slow terrestrial (often insular) species primarily to human exploitation. The other large-bodied terrestrial turtles, the 000e.2 Conservation Biology of Freshwater Turtles and Tortoises • Chelonian Research Monographs, No. 5As an addition to the annual checklist of extant modern turtle taxa (Turtle Taxonomy Working Group [TTWG] 2014), we here present an annotated checklist of extinct Pleistocene and Holocene turtle and tortoise species that existed in relatively recent times, prior to 1500 AD, during the history of the rise and global spread of humanity and concurrent global climatic and habitat changes. These species, recorded from archaeological and paleontological sites from the Pleistocene and Holocene epochs (Quaternary period), approximately the last 2.6 million years, are currently considered to be valid, and not synonymous with modern (post-1500 AD) taxa.These fossil species, including some unnamed taxa of indeterminate or undescribed generic or specific allocation, represent the majority of the chelonian diversity that has gone extinct relatively recently. Many of these taxa were likely extirpated by anthropogenic exploitation over the relatively long prehistory of earlier hominin (e.g., Homo erectus, H. neanderthalensi...

We have prepared polyacetylene (ν-(CH) x ) yielding a conductivity of more than 105 S/cm, by making some modifications on Naarmann et al.'s method. Structural analyses of this polymer were carried out by use of various analysis techniques such as SEM, IR and resonance Raman spectroscopy to characterize ν-(CH) x . No distinct differences in structure between conventional polyacetylene and ν-(CH) x were observed except for morphology and specific gravity. Upon iodine doping, conductivity increases stepwisely, which may suggest the formation of a staging structure and/or the transformation to metallic phase. However, in the temperature dependence of conductivity, we could not find any differences which distinguish the metallic ν-(CH) x from conventional polyacetylene.

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Two new nitrile-containing diamine monomers, 4-[bis(4-aminophenyl)amino]benzonitrile and 4-[4-(1-cyanopropoxy)phenyl]2,6-bis(4-aminophenyl)pyridine were synthesized. The diamine monomers were reacted with various tetracarboxylic dianhydrides, followed by cyclodehydration (imidization) without isolation to produce a series of novel polyimides with pendant nitrile groups on the side chain. The polymers were obtained in quantitative yields with high molecular weight. Among them, polymers derived from ODPA and 6FDA showed good solubility, they could dissolve in polar solvents such as DMF, NMP, DMSO and even pyridine and m-cresol. These tough, transparent and flexible polyimide films had a tensile strength of 80–120 MPa, an elongation at break of 4–12% and a tensile modulus of 1.2–2.3 GPa. The polymers obtained exhibited high glass transition temperatures between 305 and 360 C. Moreover, they were fairly stable up to a temperature around or above 400 C and lost 10% weight in the range of 500–590 C and 470–580 C in nitrogen and air, respectively. Together the dielectric constants of the polyimides were measured to be 3.10–3.73 at 10 GHz. On the other hand, blank polyimides with no – CN groups were also prepared for comparison and the results revealed that the nitrile group affected the thermal property of polyimides as well as the electrical properties. Introduction of the –CN groups would increase the glass transition temperature and also the dielectric constant.

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