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Warren L. Kovach

Warren L. Kovach
Kovach Computing Services

PhD

About

30
Publications
4,774
Reads
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2,495
Citations
Introduction
Skills and Expertise
Education
August 1981 - July 1987
Indiana University Bloomington
Field of study
  • Paleobotany
September 1977 - June 1981
Hiram College
Field of study
  • Biology

Publications

Publications (30)
Data
These data were used to produce: Batten, David J. & Kovach, Warren L., 1990. Catalog of Mesozoic and Tertiary Megaspores. American Association of Stratigraphic Palynologists, Contribution Series, Vol. 24, 227pp. The data were originally in a Borland Paradox database, but were converted to an Excel workbook in 2018 by Warren Kovach. These data ca...
Conference Paper
Full-text available
Over the past two decades the Countryside Council for Wales has been undertaking a systematic survey of Welsh lakes designed to describe the biodiversity resource and understand the biogeographical context at a British and regional scale. Almost 80 lakes in Wales have been surveyed using a standard method which records plant species present and a r...
Article
Full-text available
1.A revised classification scheme is described for standing waters in Britain, based on the TWINSPAN analysis of a dataset of aquatic plant records from 3447 lakes in England, Wales and Scotland, which is held by the Joint Nature Conservation Committee.2.Separate ecological descriptions of 11 distinct lake groups (A–J) are presented with summary en...
Book
The first comprehensive classification scheme for standing waters in Britain (Palmer 1992; Palmer et al. 1992) was based on macrophyte surveys carried out by the Nature Conservancy Council (NCC) from 1124 standing waters throughout England, Scotland and Wales between 1975 and 1988. This dataset became an important source of information used for a v...
Article
Full-text available
Land plant physiognomy has long been used to estimate climate parameters, mainly by single characters such as the proportion of entire to non-entire leaf margins in a sample. The relatively new technique of canonical correspondence analysis can analyse large numbers of characters, directly relate these to known environmental data, and test the sign...
Article
Littoral microcrustacean (Ctenopoda, Anomopoda, Onchyopoda) samples, aquatic macrophyte data and chemical measurements were collected from 51 freshwater lochs in the Isle of Skye, Scotland, during the summer of 1989. Canonical correspondence analysis was employed to investigate correlations between the environmental data, the microcrustacean assemb...
Article
Full-text available
Iridescent exines have previously been reported in both fossil and modern megaspores of selaginellalean affinity. This striking feature has been shown to result from a colloidal crystal configuration of the exine units in at least part of the wall. This paper discusses the mechanics of formation of the colloidal crystal and of the adjacent wall lay...
Article
Multivariate techniques summarize large sets of data and present their major trends in a graphically simplified manner. This paper discusses ways in which these techniques can be used to correlate biostratigraphical data. Stratigraphically constrained cluster analyses, which highlight distinct zones, may be performed on a number of sections. These...
Article
Quantitative data on lycopsid and aquatic fern megaspore taxa recovered from Carboniferous, Mesozoic, and Tertiary strata have been compiled in order to analyze the changes in diversity of the two groups of fossil plants that produced them. The data suggest that lycopsids were more diverse in the Mesozoic than previously thought and there is a pres...
Article
Representatives of 32 chydorid taxa were collected. Minimum variance clustering and principal components analysis of the data set allowed recognition of three geographically distinct sampling site groups: Western, Central Lowlands and Countrywide. Seven groups of chydorid taxa were identified on the basis of their total frequencies of occurrence, f...
Book
Full-text available
This volume provides a taxonomic and nomenclatural index to all genera and species of Mesozoic and Tertiary megaspores known to us as of the end of 1989. It is divided into five parts. The first, which is by far the longest, comprises a species database in which more than 3200 records are arranged in alphabetical order according to genus. Included...
Article
This paper presents data on the stratigraphic ranges of all known Mesozoic and Tertiary megaspores from around the world and demonstrates the potential of these palynomorphs for dating and correlating sedimentary sequences. Forms referable to more “natural”; genera such as Ariadnaesporites and Paxillitriletes, as opposed to those that are based sol...
Article
Multivariate analyses are often used in ecology and have proved to be useful in plant paleoecology and palynology. A variety of different methods are available, but these methods have different mathematical bases and different assumptions about the data to be analyzed, which must be kept in mind when analyzing a particular data set. This paper pres...
Article
The study of spore wall ultrastructure has provided much useful information in comparisons between fossil and modern taxa. Recently, some features of lycopod megaspore ultrastructure have been noted which may allow for comparisons between fossil and modern megaspores. These differences include the porosity of the megaspore wall and the variability...
Article
Full-text available
Bulk maceration and sieving of terrestrial and marginal marine sediments from the Dakota Formation (Cretaceous, Ce‐nomanian) of Kansas yielded a diverse assemblage of dispersed plant fossils, including 16 species of lycopod and heterosporous fern megaspores, six species of seed and fruit cuticles, four types of bilobed cuticular structures which ma...
Article
Bulk maceration of sediments from the Dakota Formation of Kansas, USA yielded a diverse assemblage of dispersed plant fossils, consisting of megaspores, seed cuticles, algal cysts, and other small plant fragments. Species abundance data were collected from samples within this transgressive sequence, which includes depositional environments ranging...
Article
A new angiosperm fructification, Caloda delevoryana, is described from the Cenomanian age Dakota Formation of central Kansas. It consists of a long, narrow, main axis with numerous secondary axes arranged helically around the main axis. These secondary axes are each terminated in a small receptacle bearing numerous conduplicate carpels. No evidence...
Article
Full-text available
Large numbers of a new species of megaspore, Paxillitriletes vittatus, have been recovered through bulk maceration of a sample from the Dakota Formation (Cenomanian) of Kansas. Transmission electron microscopy has revealed a spore wall ultrastructure similar to both modern and fossil lycopod mega‐spores, consisting of a spongy reticulum of sporopol...
Article
KOVACH, W. L. & DILCHER, D. L., 1984. Dispersed cuticles from the Eocene of North America. Macerations of organic-rich clay from the Claiborne Formation (Middle Eocene) of Tennessee have yielded a wide variety of well-preserved dispersed cuticles. Details of the epidermal cell patterns, arrangement of the stomata1 complex, trichomes and trichome at...