DOI: 10.5061/dryad.vx0k6dk2d
title: Data from: Morphometric analysis of the conodont Chiosella timorensis (Nogami) from the early Anisian of Romania and China, and its significance for the definition of the Olenekian-Anisian Boundary

description: The conodont Chiosella timorensis (Nogami) has long been proposed as a
 biotic proxy for identifying the Olenekian-Anisian Boundary (OAB).
 However, uncertainty regarding the relationship between this species and
 its presumed ancestor, Ch. gondolelloides (Bender) and its stratigraphic
 range have cast doubt on its suitability as a proxy. Morphometric analysis
 of large populations of Chiosella from the Global Stratotype Section and
 Point candidate at Deşli Caira, as well as other OAB sections in south
 China, demonstrate that most morphological variation in this genus is
 caused by variability in the position of the cusp, not the length of the
 mid-lateral rib (traditionally used to separate the species Ch.
 gondoelloides and Ch. timorensis). Furthermore, there is little to no
 stratigraphic separation between the two species, and no obvious trend in
 any of the investigated sections of a morphological shift from one species
 to the other with increasing stratigraphic height. Finally, when
 investigating the size variation of the population, it becomes apparent
 that in general, specimens assigned to Ch. gondolelloides are much smaller
 than those Ch. timorensis. Taken together, the results of this study imply
 that most specimens of Ch. gondolelloides should be considered to be
 juvenile forms of Ch. timorensis. If Ch. timorensis is used as the biotic
 proxy for the OAB, then the results of this morphometric analysis
 necessitate the base of the Anisian be moved down in several OAB sections,
 including Deşli Caira. Despite this, the study provides greater taxonomic
 stability, enhancing the utility of Ch. timorensis for future
 stratigraphic correlation.
description: A total of 168 specimens of <em>Chiosella</em> from
 Desli Caira, Guandao and Mingtang were utilized for the morphometric
 analysis.  Specimens were first photographed in lateral
 view, and the JPEG file were converted ro TPS files using the software
 TpsUtil, before the positions of all landmarks were identified per
 specimen in the software TpsDig. Eleven landmarks were utilized, in an
 attempt to capture the morphology of the specimens. 
 Morphometric analyses were subsequently conducted using the
 software MorphoJ. First, a generalized Procrustes analysis was conducted
 on each species dataset, which minimizes all variation in specimen
 position, size, and rotation, in order to conserve only variation in
 specimen shape. Then, a wireframe model was created for each species,
 where landmark points are linked in a consistent manner to better
 facilitate visualization of form changes. Finally, eigenanalyses were
 carried out, both Principal Components Analysis (PCA) and Canonical
 Variate Analysis (CVA). Both analyses generate eigenvectors that represent
 axes that maximize separation of sets in multivariate space; however, CVA
 utilizes sets that are externally predefined by classifiers. In the
 present study, the predefined classifiers were stratigraphic section
 (either Desli Caira, Guandao, or Mingtang) in one analysis, and
 stratigraphic height (i. e. sample number in each section, with 1 being
 the lowest sample) for another analysis. Both PCA and
 CVA have strengths and weaknesses; therefore, it is advisable to use both
 techniques in tandem, and to use them to answer different
 questions.  In order to compare the size of specimens
 of <em>Chiosella</em>, measurements of height and length were
 made directly off of the same, scaled SEM photographs that were used to
 conduct the landmark analysis, as well as other proviously published
 images from South China and Nevada.
description: # Data from: Morphometric analysis of the conodont *Chiosella timorensis*
 (Nogami) from the early Anisian of Romania and China, and its significance
 for the definition of the Olenekian-Anisian Boundary
 [https://doi.org/10.5061/dryad.vx0k6dk2d](https://doi.org/10.5061/dryad.vx0k6dk2d) ## Description of the data and file structure This readme file was generated on 2024-11-15 by Shunling Wu. ## Data and file overview File List: 1._conodonts_landmark.csv 2._conodonts_species_PCA.csv 3._conodonts_sections_CVA.csv 4._conodonts_Desli Caira_beds_CVA.csv 5._conodonts_Guandao_beds_CVA.csv 6._conodonts_Mingtang_beds_CVA.csv 7._Individual size.csv ### Data-specific information for: 1._conodonts_landmark.csv This file contains the coordinates of the landmark points placed on the element contour of each studied specimen. The data were made by TpsDig and TpsUtil. Number of variables (columns): 15 Number of specimens (rows): 168 Variable List: sections, species, number, sample, (X1, Y1), (X2, Y2), (X3, Y3), (X4, Y4), (X5, Y5), (X6, Y6), (X7, Y7), (X8, Y8), (X9, Y9), (X10, Y10), (X11, Y11). ### Data-specific information for: 2._conodonts_species_PCA.csv This file contains the scores along the resulting axes derived from the principal component analysis of the data stored in 1._conodonts_landmark.csv. The analysis was made by Morpho J. Number of variables (columns): 19 Number of specimens (rows): 22 Variable List: landmark axis, PC1, PC2, PC3, PC4, PC5, PC6, PC7, PC8, PC9, PC10, PC11, PC12, PC13, PC14, PC15, PC16, PC17, PC18. Abbreviations used: 1\. PC: principal component ### Data-specific information for: 3._conodonts_sections_CVA.csv This file contains the scores along the resulting axes derived from the canonical variate analysis of the data stored in 1._conodonts_landmark.csv. The analysis was made by Morpho J. Number of variables (columns): 3 Number of specimens (rows): 22 Variable List: landmark axis, CV1, CV2. Abbreviations used: 1\. CV: canonical variate ### Data-specific information for: 4._conodonts_Desli Caira_beds_CVA.csv This file contains the scores along the resulting axes derived from the canonical variate analysis of the data of Desli Caira section stored in 1._conodonts_landmark.csv. The analysis was made by Morpho J. Number of variables (columns): 18 Number of specimens (rows): 22 Variable List: landmark axis, CV1, CV2, CV3, CV4, CV5, CV6, CV7, CV8, CV9, CV10, CV11, CV12, CV13, CV14, CV15, CV16, CV17. Abbreviations used: 1\. CV: canonical variate ### Data-specific information for: 5._conodonts_Guandao_beds_CVA.csv This file contains the scores along the resulting axes derived from the canonical variate analysis of the data of Guangdao section stored in 1._conodonts_landmark.csv. The analysis was made by Morpho J. Number of variables (columns): 19 Number of specimens (rows): 22 Variable List: landmark axis, CV1, CV2, CV3, CV4, CV5, CV6, CV7, CV8, CV9, CV10, CV11, CV12, CV13, CV14, CV15, CV16, CV17, CV18. Abbreviations used: 1\. CV: canonical variate ### Data-specific information for: 6._conodonts_Mingtang_beds_CVA.csv This file contains the scores along the resulting axes derived from the canonical variate analysis of the data of Mingtang section stored in 1._conodonts_landmark.csv. The analysis was made by Morpho J. Number of variables (columns): 14 Number of specimens (rows): 22 Variable List: landmark axis, CV1, CV2, CV3, CV4, CV5, CV6, CV7, CV8, CV9, CV10, CV11, CV12, CV13. Abbreviations used: 1\. CV: canonical variate ### Data-specific information for: 7._Individual size.csv This file contains the data of the length and height of of *Chiosella* from South China, India, Japan, Romania, and North America. Number of variables (columns): 6 Number of specimens (rows): 182 Variable List: section, species, samples, length(μm), height(μm), notes Abbreviations used: 1\. DC: Desli Caira 2\. GD: Guandao 3\. MT: Mingtang 4: gondolelloides: *Ch. gondolelloides* 5\. timorensis: *Ch. timorensis* ## Access information Other publicly accessible locations of the data: * Wu, S. Golding, M. Han, C. Lyu, Z. and Zhao, L. 2024. Morphometric analysis of the conodont *Chiosella timorensis* (Nogami) from the early Anisian of Romania and China, and its significance for the definition of the Olenekian-Anisian Boundary.