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Studies of Paleozoic Seed Ferns: Anatomy and Morphology of Morphology of Microspermopteris aphyllum.
Download1976
The discovery of numerous specimens of the monostelic pteridosperm genus Microspermop- teris in Pennsylvanian coal ball petrifactions from the Lewis Creek and What Cheer localities provides additional information about the anatomical and morphological variability within the genus. Specimens are...
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Formation and Morphology of an Iron Plaque on the Roots of Typha latifolia L. Grown in Solution Culture.
Download1984
Taylor, G.J., Rodden, R., Crowder, A.A.
Roots of Typha latifolia L. exposed to Fe2+ under reduced conditions in solution culture developed visible coatings (plaques) of an oxidized Fe compound that extended as much as 15-17 ,um into the rhizosphere. Iron concentrations were significantly less and discoloration was not apparent on the...
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1997
Rothwell, Gar W., Stockey, Ruth A., Hoffman, Georgia L.
More than 200 specimens of Limnobiophyllum scutatum (Dawson) Krassilov have been recovered from lacustrine claystones in the Paleocene Paskapoo Formation near Red Deer, Alberta. The plant was a floating, aquatic angiosperm with helically arranged, ovate leaves attached in small rosettes. Rosettes...
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Leg size affects male mating success in Tarsonemus confusus Ewing (Prostigmata: Tarsonemidae)
Download1997
Belczewski, R., Garga, N., Proctor, H.
Legs IV of males in the family Tarsonemidae are highly modified to form thickened pincer-like appendages. Previous literature describes males using legs IV both to manipulate pharate females onto the males' genital capsule as well as to constrain the adult female's legs during mating. We observed...
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Phylogenetic Congruence and Discordance among One Morphological and Three Molecular Data Sets from Pontederiaceae
Download1998
Kohn, Joshua R., Graham, Sean W., Barrett, Spencer C.H., Eckenwalder, James E., Morton, Brian R.
A morphological data set and three sources of data from the chloroplast genome (two genes and a restriction site survey) were used to reconstruct the phylogenetic history of the pickerelweed family Pontederiaceae. The chloroplast data converged towards a single tree, presumably the true...
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Palaeoenvironment and palaeoecology of three Cretaceous snakes: Pachyophis, Pachyrhachis, and Dinilysia
Download2001
Caldwell, M. W., Albino, A. M.
The palaeoecology of three Late Cretaceous snakes is evaluated. Pachyophis woodwardi Nopcsa, 1923 and Pachyrhachis problematicus Haas, 1979, are Cenomanian in age and are found in carbonate rocks deposited in marine inter-reef basin environments of the European and African Tethys Sea. Dinilysia...
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2003
Hurum, J. H., Sabath, K., Currie, P. J.
Tyrannosauridae can be subdivided into two distinct subfamilies-the Albertosaurinae and the Tyrannosaurinae. Previously recognized subdivisions Aublysodontinae and Shanshanosaurinae are rejected because they are based on insufficient material and juvenile specimens. Our results are based upon a...
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2004
Populations of a host species may exhibit different assemblages of parasites and other symbionts. The loss of certain species of symbionts (lineage sorting, or ‘‘missing-the-boat’’) is a mechanism by which geographical variation in symbiont assemblages can arise. We studied feather mites and lice...
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Identification of Dioryctria (Lepidoptera : Pyralidae) in a seed orchard at Chico, California
Download2006
Gillette, N. E., Sperling, F. A. H., Roe, A. D., Stein, J. D.
Abstract: Species of Dioryctria Zeller (Lepidoptera: Pyralidae) are important pests of conifers, particularly in seed orchards, and accurate species identification is needed for effective monitoring and control. Variable forewing morphology and lack of species-specific genitalic features hinder...