Publications by authors named "W E Holznagel"

Pulmonate snails occupy a wide range of marine, estuarine, freshwater and terrestrial environments. Non-terrestrial forms are supposed to be basal in pulmonate evolution but the group's phylogeny is not well resolved either morphologically or on the basis of available DNA sequence data. The lack of a robust phylogeny makes it difficult to understand character polarization and habitat transformation in pulmonates.

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The order Chytridiales is the largest and most diverse of five orders in phylum Chytridiomycota. Rhizophydium is one of two genera in the Chytridiales with more than 220 described species. Because thallus characters used in classical descriptions of Rhizophydium species often intergrade into other species, as well as other genera, species distinctions frequently are unclear.

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The Cerithioidea is a very diverse group of gastropods with ca. 14 extant families and more than 200 genera occupying, and often dominating, marine, estuarine, and freshwater habitats. While the composition of Cerithioidea is now better understood due to recent anatomical and ultrastructural studies, the phylogenetic relationships among families remain chaotic.

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Mollusks are an extraordinarily diverse group of animals with an estimated 200,000 species, second only to the phylum Arthropoda. We conducted a comparative analysis of complete mitochondrial ribosomal large subunit sequences (LSU) of a chiton, two bivalves, six gastropods, and a cephalopod. In addition, we determined secondary structure models for each of them.

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