Cladistic and Phenetic Recognition of Species in the Ordovician Bryozoan Genus Peronopora

Anstey, Robert L.; Pachut, Joseph F.

doi:10.1666/0022-3360(2004)078<0651:capros>2.0.co;2

Cited by 11 publications

(14 citation statements)

References 32 publications

(57 reference statements)

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“…Key apomorphic character states, useful in identifying individual species, are discussed below (a complete listing is provided in online Supplemental file 11). All three species are recognizable both phenetically and cladistically, a result similar to that found in species and metaspecies of the Upper Ordovician bryozoan genus Peronopora (Pachut and Anstey, 2002;Anstey and Pachut, 2004). However, cladistics provides advantages over phenetics by making it possible to reduce the effects of convergent (homoplastic) characters in establishing relationships and by permitting the identification of characters and character states that unite specimens within each clade and those that separate different clades from each other.…”

Section: Gwxsupporting

confidence: 66%

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

Pachut

Horowitz

2013

J. Paleontol.

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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.

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Section: Gwxsupporting

confidence: 66%

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

Pachut

Horowitz

2013

J. Paleontol.

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“…Quantitative morphometric methods have long been used to classify organisms. Discriminant function analysis (DFA) or canonical variates analysis (CVA) are often used to support the identification of distinct species, particularly in fossil lineages [ 1 - 4 ] and alternative statistical approaches to the classification of specimens based on maximum likelihood methods have also been developed [ 5 ]. The explicit assumption is that a low rate of misclassification of individuals from two populations provides evidence for genetic differences [ 6 ].…”

Section: Introductionmentioning

confidence: 99%

Comparison of geometric morphometric outline methods in the discrimination of age-related differences in feather shape

et al. 2006

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Background: Geometric morphometric methods of capturing information about curves or outlines of organismal structures may be used in conjunction with canonical variates analysis (CVA) to assign specimens to groups or populations based on their shapes. This methodological paper examines approaches to optimizing the classification of specimens based on their outlines. This study examines the performance of four approaches to the mathematical representation of outlines and two different approaches to curve measurement as applied to a collection of feather outlines. A new approach to the dimension reduction necessary to carry out a CVA on this type of outline data with modest sample sizes is also presented, and its performance is compared to two other approaches to dimension reduction.

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“…Our data set consists only of fossilized specimens from extinct bryozoan genera. We have extended the concept of crown and stem groups to our analysis of monticuliporid genera based on the topological structure of our cladogram, an approach applied earlier by Anstey and Pachut (2004) in defining species and metaspecies of the Ordovician bryozoan genus Peronopora.…”

Section: Discussionmentioning

confidence: 99%

“…Pachut and Anstey (2002) recognized eight species of Peronopora. A later paper (Anstey and Pachut, 2004) extended their earlier analysis by comparing cladistically-defined species to those recognized using phenetic methods. They identified eight monophyletic crown group species, one of which (P. browni) was new, and eight non-monophyletic metaspecies.…”

Section: Previous Cladistic Studiesmentioning

confidence: 99%

“…More recently, Pachut and Anstey (2002) applied cladistic techniques to a data set consisting of 202 specimens, recognizing eight species of the Middle and Upper Ordovician bryozoan genus Peronopora. A subsequent paper (Anstey and Pachut, 2004) extended the earlier analysis by comparing cladisticallydefined species to those recognized using phenetic methods. Eight Boardman and Utgaard (1966), plate 133, figures 1a and 1b, respectively: 1, tangential section of massive topotype with abundant mesozooecia in central macula and common cystiphragms (USNM 146486); 2, longitudinal section of same zoarium (USNM topotype suite 43829) illustrating a monticule at the top of the image; vertical, attenuated, mesozooecia bend out of the plane of the section; 3, 4, Peronopora decipiens (lectotype, UMMP 6676-3), from Boardman and Utgaard (1966), plate 135, figures 1c, 1f, respectively: 3, tangential section illustrating a monticule and mesozooecia; 4, longitudinal section showing a break in median lamina (broken vertical line), making it discontinuous, and autozooecia budding from its left and right sides; overlapping series of cystiphragms are common within autozooecia;.…”

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confidence: 99%

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Cladistic analysis of the Paleozoic bryozoan families Monticuliporidae and Mesotrypidae

Adamczyk

Pachut

2013

J. Paleontol.

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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 representing 12 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 while stem group membership matches the 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.

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Cladistic and Phenetic Recognition of Species in the Ordovician Bryozoan Genus Peronopora

Cited by 11 publications

References 32 publications

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

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

Comparison of geometric morphometric outline methods in the discrimination of age-related differences in feather shape

Cladistic analysis of the Paleozoic bryozoan families Monticuliporidae and Mesotrypidae

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