Stratigraphic and Geographic Bryozoan Abundance Gradients in the Calcareous Shales of the Wreford Megacyclothem (Lower Permian, Kansas)

17 p., 3 fig., 13 tables.http://paleo.ku.edu/contributions.htm

Data from: Cladistic assignment of specimens to species of the cystoporate bryozoan genera Strotopora Ulrich and Cliotrypa Ulrich and Bassler using gap-coded characters

Gap-coding permits the use of continuous metric characters in cladistic analyses. Character means are converted to integer equivalents by placing character state divisions in the locations of phenetic breaks between specimen clusters, under the assumption that these breaks represent the locations of bottlenecks in character distributions. Similarities and differences between specimens from closely related species of cystoporate bryozoans were evaluated for the first time by converting continuous morphometric measurements into gap-coded binary and multistate characters and analyzing them cladistically, rather than just phenetically, across multiple species of Strotopora, Cliotrypa ramosa and Fistulipora compressa. Our results demonstrate that cladistic analysis of gap-coded morphological characters can be effective in resolving phylogenetic relationships at low taxonomic levels (within and among genera) while objectively highlighting both the morphological features that specimens (taxa) share and those characteristics that differentiate them. Differences in cystiphragm abundances and sizes, especially in the proximal portions of colonies, discriminate between species of Strotopora. Colony size and growth form, abundances and lengths of hemiphragms, and sizes of cystopores discriminate between Strotopora and the closely related genus Cliotrypa. Cladistic patterns indicate that Strotopora foveolata Ulrich is a valid species with Strotopora dermata as its junior subjective synonym. Fistulipora compressa is reassigned to the genus Strotopora whereas a decision on the taxonomic status of Cliotrypa ramosa requires a broader cladistic analysis of fistuliporine genera

Data from: Rates of anagenetic evolution and selection intensity in Middle and Upper Ordovician species of the bryozoan genus Peronopora

Evolutionary rates and selection intensities in eight cladistically defined species-level evolutionary sequences of the Middle and Upper Ordovician bryozoan genus Peronopora were calculated for comparison with values published for fossil and living taxa. Calculations were restricted to statistically significant unidirectional segments of anagenetic series to minimize the mixing of different modes, directions, and rates of evolutionary change. Rates and selection intensities ranged from 10^−7 to 10^−6 darwins and from 10^−6 to 10^−5 haldanes. Across characters, the weighted mean evolutionary rate equaled 5.86 × 10^−7 darwins and the mean selection intensity was 6.44 × 10^−7. Mean rates of 2.15 × 10^−6, 4.31 × 10^−6, and 8.61 × 10^−6 haldanes, and corresponding mean selection intensities equaling 2.39 × 10^−6, 4.78 × 10^−6, and 9.56 × 10^−6, were calculated for generation lengths of 0.5, 1, and 2 years, respectively. The magnitudes of positive and negative evolutionary rates and selection intensities do not differ statistically, individual characters display no consistent pattern of positive or negative values, and no character complexes were detectable. A mosaic pattern of change occurs across characters in evolutionary sequences. Eighty percent of analyzed evolutionary series were multispecies lineages. Both individual and mean values provide direct estimates of the rates of evolution within those lineages at the moment of speciation. Rates of anagenetic evolution in Peronopora were low and similar to published rates for a variety of fossil protists, invertebrates, and vertebrates. However, earlier rate calculations did not isolate the effect of unidirectional anagenesis from that of stasis, random walks, trend reversals, or rate variations. Eight percent of characters in Peronopora produced anagenetic series that were statistically significant, a percentage similar to the 5% calculated in a study of 251 sequences of evolving traits in 53 fossil lineages (Hunt 2007). Stasis and mutation-drift are the most common patterns detectable in the fossil record, although anagenesis remains a potentially important force in shaping the course of both micro- and macroevolution

Data from: Cladistic analysis of the Paleozoic bryozoan family Monticuliporidae and Mesotrypidae

A set of 127 binary and multistate characters, weighted by the number of derived character states, degree of covariation, and level of homoplasy, was used in a cladistic analysis of type species representing12 genera previously assigned to families Monticuliporidae and Mesotrypidae. The most parsimonious tree consisted of a 10-genus monophyletic crown group with the remaining two genera forming a basal paraphyletic stem group. The composition of the monticuliporid crown group is broadly similar to two earlier classifications (Astrova 1978; Marintsch 1998) while stem group membership matches that of Astrova's (1965, 1978) family Mesotrypidae. Phenetic groupings, based on overall morphological similarity, have memberships that are similar to those of clades but provide no means of determining the polarity of evolutionary relationships either within or between them. Finally, only the observed stratigraphic ranges of the type species of genera provide a statistically significant match with cladistic branching sequence, perhaps because current composite generic ranges reflect the mixing of species belonging to different genera. Based on cladogram topology, we propose the placement of all 12 genera into a single family Monticuliporidae

APPENDIX 3

Apomorphy listing, by cladogram node, for the heuristic analysis that was reweighted by maximum value of the rescaled consistency index (RC). RC ranges between 0.0 and 1.0 and is a (directly) proportional measure of a character’s fit to a tree. Triangles (►) indicate changes occurring in every possible tree reconstruction, whereas arrows (→) indicate changes in this reweighted analysis, and possibly in others, but not in all analyses

Pachut & Anstey - Supplemental Appendices

Appendix 1 - Summary statistics, heritability, and number of generations for portions of unbranched evolutionary sequences displaying intermediate-strength anagenesis. Appendix 2 - Summary statistics, heritability, and number of generations for portions of unbranched evolutionary sequences displaying weak anagenesis. Appendix 3 - Rates of evolution, in darwins, calculated in previous studies for 93 taxa of fossil protists and invertebrates

APPENDIX 2

Character states for 127 morphologic characters used in cladistics analysis. Characters, and character states, are defined in Appendix 1. Question marks reflect uncertain character state codes. The genus Goryunovia was utilized as an outgroup

APPENDIX 1

The 127 coded characters used in cladistic analyses of genera assigned to families Monticuliporidae and Mesotrypidae. These characters were cladistically informative (i.e., were synapomorphic) having states shared by in-group genera. This is a partial listing of 267 characters developed from the following sources (R. L. Anstey, personal communication): Anstey (1978), Anstey (1990), Anstey and Pachut 1995 (Appendices A and B), Anstey and Perry (1970, 1973), Blake and Snyder (1987), Corneliussen and Perry (1973), Cuffey and Blake (1991), Hageman (1991), Hickey (1988), Key (1990), McKinney (1977, 2000), Pachut and Anstey (1984), Pachut, Anstey, and Horowitz (1994), Prezbindowski and Anstey (1978), Spearing (1998), Tang and Cuffey (1998), and Taylor and Weedon (2000). Characters that could not be evaluated within a genus were coded using a question mark