This WITTS_2022__DATA_README.txt file was generated on 2022-04-04 by James D. Witts GENERAL INFORMATION 1. Title of Dataset: Data from: Geographic and temporal morphological stasis in the latest Cretaceous ammonoid Discoscaphites iris from the U.S. Gulf and Atlantic Coastal Plains. 2. Author Information Corresponding Investigator Name: Dr James Witts Institution: School of Earth Sciences, University of Bristol, UK Email: james.witts@bristol.ac.uk Co-investigator 1 Name: Dr Corinne Myers Institution: Department of Earth and Planetary Sciences, University of New Mexico, USA Co-investigator 2 Name: Matthew Garb Institution: Department of Earth and Environmental Sciences, Brooklyn College, USA Co-investigator 3 Name: Kayla Irizarry Institution: Department of Geosciences, The Pennsylvania State University, USA Co-investigator 4 Name: Dr Ekaterina Larina Institution: Department of Earth Sciences, University of Southern California, USA Co-investigator 4 Name: Anastasia Rashkova Institution: Division of Paleontology (Invertebrates), American Museum of Natural History, USA Co-investigator 6 Name: Dr Neil Landman Institution: Division of Paleontology (Invertebrates), American Museum of Natural History, USA 3. Date of data collection: 2017-2021 4. Geographic location of data collection: Gulf Coastal Plain [Mississippi, Missouri, Texas] and Atlantic Coastal Plain [New Jersey], USA 5. Funding sources that supported the collection of the data: American Museum of Natural History and Richard Gilder Graduate School, United States National Science Foundation 6. Recommended citation for this dataset: Witts et al. (2022), Data from: Geographic and temporal morphological stasis in the latest Cretaceous ammonoid Discoscaphites iris from the U.S. Gulf and Atlantic Coastal Plains, Dryad, Dataset DATA & FILE OVERVIEW 1. Description of dataset We assembled a large morphometric dataset consisting of 328 individual fossil specimens of the scaphitid ammonoid cephalopod Discoscaphites iris collected from nine localities in Texas, Missouri, Mississippi, and New Jersey, representing a ~2000 km transect from SW to NE and encompassing the full geographic range of Discoscaphites iris. Morphometric parameters were measured on well-preserved adult specimens of two dimorphs (Macroconchs - presumably the female, and microconch, presumably the male). We took up to seven morphometric measurements, and calculated ratios that captured the size, shape, and degree of compression of each of these individual ammonoid shells from seven different localities. We evaluated the coefficient of variation (the standard deviation divided by the mean) for size and shape ratios, as well as compression ratios at each locality. We used non-parametric statistical tests [Mann-Whitney U] to evaluate the significance of changes in mean morphological trait values in populations between localities. To correct for multiple comparisons we applied a Bonferroni correction and also controlled for the false discovery rate in adjusting p-values. We also explored relationships between morphological traits and several environmental variables using linear modelling. All analyses were conducted in the R programming environment. 2. File List: File 1 Name: Witts_2022_1_Supplementary_text_figures.pdf File 1 Description: PDF containing Supplementary Figures, full taxonomic description of the ammonoid species Discoscaphites iris, and details of assumed evolutionary relationships from the published literature. File 2 Name: Witts_2022_2_Macroconch_data.xlsx File 2 Description: Locality information, morphometric measurements taken from specimens of D. iris identified as macroconchs and environmental information. File 3 Name: Witts_2022_3_Macroconch_stats.xlsx File 3 Description: P-values derived from statistical comparisons between localities for each morphological trait of D. iris macroconchs using Mann-Whitney U tests. Adjusted P-values after implementation of a Bonferroni correction, and the methods of Benjamini and Yekutieli and Benjamini and Hochberg in an attempt to control for the false discovery rate are also shown. Statistically significant results (p = <0.05) are highlighted in red. File 4 Name: Witts_2022_4_microconch_data.xlsx File 4 Description: Locality information, morphometric measurements taken from specimens of D. iris identified as microconchs and environmental information. File 5 Name: Witts_2022_5_microconch_stats.xlsx File 5 Description: P-values derived from statistical comparisons between localities for each morphological trait of D. iris microconchs using Mann-Whitney U tests. Adjusted P-values after implementation of a Bonferroni correction, and the methods of Benjamini and Yekutieli and Benjamini and Hochberg in an attempt to control for the false discovery rate are also shown. Statistically significant results (p = <0.05) are highlighted in red. File 6 Name: Witts_2022_6_Rcode.txt File 6: Description: Code pipeline for completing analyses in R outlined in this manuscript. METHODOLOGICAL INFORMATION Morphometric parameters were measured on well-preserved adult specimens using electronic calipers (accuracy of 0.01 mm). Maximum length (LMAX) was measured from the venter of the phragmocone to the venter of the hook parallel to the umbilical margin; whorl height was measured at three points on the shell: the end of the phragmocone (HP), midshaft (HS), and the point of recurvature (HH); whorl width was also measured at these same points (WP, WS, WH). The ratios of whorl width to whorl height were calculated at each of these three points (e.g., WP/ HP) and provide a measure of the degree of whorl compression. Two additional shape ratios were also calculated; the ratio of maximum length to whorl height of the phragmocone along the line of maximum length (LMAX/HP) is a measure of the degree of uncoiling. The ratio of maximum length to whorl height at midshaft (LMAX/HS) is a measure of the degree of curvature of the body chamber in lateral view. If the outline of the body chamber in lateral view is a semicircle, the ratio equals 2. The ratio applies only to macroconchs because the umbilical seam of the body chamber usually coincides with the line of maximum length in these forms, and the whorl height is the distance from the line of maximum length to the venter of the body chamber (equivalent to the radius in the case of a semicircle). Shape measurements were made at each locality, but whorl compression ratios were not measured on specimens from the Brazos River localities since these specimens were still embedded in matrix. Morphological changes were evaluated using box and whisker plots to graphically examine the entire distribution of parameters across the temporal and spatial duration of the D. iris Zone. We also calculated the coefficient of variation (CV) for size and shape ratios as well as whorl compression ratios at each site. CV is the standard deviation divided by the mean value of each morphological trait and is often used as a measure of intraspecific variation in ammonoids. Non-parametric Mann-Whitney U-tests were used to evaluate the statistical significance of changes in mean morphological trait values between localities. To correct for multiple comparisons we adjusted p-values generated by the Mann-Whitney tests for each morphological trait using three methods. We applied a Bonferroni correction and also controlled for the false discovery rate using the methods of Benjamini and Hochberg (1995) and Benjamini and Yekutieli (2001). Only results considered below are those that were consistently statistically significant across all four of these methods, or at least three out of four methods if the conservative Bonferroni correction did not show significance. We also explored relationships between morphological traits and several environmental variables available at each locality using linear modelling via the LM function in R. Variables considered for each locality were: paleolatitude (available using the Paleolatitude Calculator; www.paleolatitude.org) and present-day longitude, which act as reliable proxies for original geographic location and distribution of the samples along the paleoshoreline of North America, and sediment grain size defined as % of sand-sized material derived from our analyses. All statistical analyses were implemented using RStudio with no requirement for additional packages. ABBREVIATIONS USED LOCALITIES/REPOSITORIES: AMNH; American Museum of Natural History. MAPS; Monmouth Amateur Paleontological Society. MBHI; Museum at the Black Hills Institute. USGS; United States Geological Survey. UNM; University of New Mexico. ACP; Atlantic Coastal Plain. GCP; Gulf Coastal Plain. NJ; New Jersey. EP; Ellis Pit. FS; Fourth Street. OC; Owl Creek. CR; Crowley’s Ridge. BR; Brazos River. OTHER: Paleolat; Paleolatitude. Macro; Macroconch. micro; microconch. DATA-SPECIFIC INFORMATION FOR: Witts_2022_1_Supplementary_text_figures.pdf 1. Supplementary Figure 1: images of Discoscaphites iris specimens. 2. Supplementary figures 3-4: relationship between coefficient of variation and number of specimens and stratigraphic thickness of the D. iris range zone for each locality in this study. 3. Supplementary figures 5-10: visualisations of linear modelling data for models A-D described in the text generated using the visreg function in R. Comparing morphological parameters (size, shape, shell compression) of D. iris specimens and environmental variables (grain-size, paleolatitude, longitude). DATA-SPECIFIC INFORMATION FOR: Witts_2022_2_Macroconch_data.xlsx 1. Number of variables: 23 2. Number of cases/rows: 150 3. Variable List: Sample #: Unique identifier for each specimen of Discoscaphites iris assigned by repository. Repository: Where individual fossil specimens are held. Dimorph: Macro = macroconch (presumed female). AMNH_loc.: American Museum of Natural History Locality number. Loc_code: Two digit code for locality. Formation: Geological formation that samples are derived from. LMAX: Maximum length measured along a line parallel to the umbilical seam. Hp: Shell height at the base of the phragmocone. Hs: Shell height at midshaft. HH: Shell height at the hook. Wp: Shell width at the base of the phragmocone. Ws: Shell height at midshaft. Wh: Shell height at the hook. LMAX_Hp: Ratio of maximum length over height of the shell at the base of the phragmocone, a measure of the degree of uncoiling. Lmax_Hs: Ratio of maximum length over height of the shell at midshaft. A measure of the degree of curvature of the body chamber. Wp_Hp: Ratio of whorl width to whorl height (shell compression) at the base of the phragmocone. Ws_Hs: Ratio of whorl width to whorl height (shell compression) at midshaft. Wh_Hh: Ratio of whorl width to whorl height (shell compression) at the hook. Latitude: Present-day latitude of individual localities. Longitude: Present-day longitude of individual localities. Paleolat: Palaeolatitude of localities. %Sand: Percentage of sand-sized material (>XX microns) derived from grain-size analysis of each locality. %Silt_Mud: Percentage of silt and mud-sized material (XX microns) derived from grain-size analysis of each locality. %Silt_Mud: Percentage of silt and mud-sized material (