DOI: 10.5061/dryad.q573n5tq7
title: Species occurrences of Mio–Pliocene horses (Equidae) from Florida: sampling, ecology, or both?

description: During the late Miocene and early Pliocene (latest Hemphillian, Hh4
 interval, 5.7 to 4.75 Myr) a distinctive suite of four species of extinct
 horses (Family Equidae) were widespread in North America. This includes
 Nannippus aztecus, Neohipparion eurystyle, Astrohippus stocki, and
 Dinohippus mexicanus. In Florida, two additional equid species,
 Pseudhipparion simpsoni and Cormohipparion emsliei are typically found at
 Hh4 localities. Here we compare horses from four Hh4 Florida fossil sites,
 including three from the Bone Valley mines, and a fourth from the recently
 discovered Montbrook site. Two of these have all six predicted species,
 one has five species, and one has only four species present. To explain
 these differences, we used species counts from research databases and
 rarefaction simulation to better understand the relative abundances,
 species richness, and occurrences of these horses from these four sites.
 The Palmetto Mine (Agrico) site, with five equid species, appears to lack
 the sixth species because of ecological reasons. This is different from
 Montbrook, the site with only four of the six species. Results indicate
 that Montbrook is likely lacking the two missing equid species for
 multiple reasons: one because of sampling bias and the other because of
 biological/ecological reasons. Our results demonstrate that sampling
 biases can account for observed equid species richness when the overall
 abundance of certain equid species is low. Nevertheless, other factors,
 including ecology and with sufficient resolution, perhaps also time, may
 also explain the distribution and occurrences of individual species at
 these and other fossil sites.
description: # Species occurrences of Mio–Pliocene horses (Equidae) from Florida:
 sampling, ecology, or both? Access this dataset on Dryad:
 [https://doi.org/10.5061/dryad.q573n5tq7](https://doi.org/10.5061/dryad.q573n5tq7) The Supplementary Data section contains five files: (1) UF VP Collections Database Query (2) Township, Range, and Section Maps (3) Raw counts by equid species/sites (4) R script (rarefaction code) (5) Data Output (rarefaction) ## Description of the data and file structure **Datasets include:** Supplement 1: Search of the University of Florida Vertebrate Paleontology Database * Queried "Equidae", "Neogene-Hh4", "Florida" * Downloaded datasets for the following Florida Hh4 localities: Montbrook, Palmetto Mine (Agrico), Kingsford Mine, and Fort Greene Mine South Supplement 2A-D: Specify Database search images of township, range, and section maps for the test localities * Queried via Specify Database, searches for Montbrook, Palmetto Mine (Agrico), Kingsford Mine, and Fort Greene Mine South * Downloaded township, range, and section map details for each fossil locality Supplement 3: Table of the number of equid species occurrences by Hh4 Florida fossil localities * Number of occurrences for the equid species (Family Equidae) from the Hh4 localities in this study in table format and in complement to Figure 4 of the manuscript. Supplement 4: R code using Vegan Package for rarefaction simulations * Raw R code specific to the manuscript. Supplement 5: R code simulation outputs for test sites * Dataset displaying outputs from R code * Columns indicate (A) Sampling Attempt Number, (B) Estimated Number of Taxa Expected, (C) Standard Deviation, (D) Lower Confidence Interval, (E) Upper Confidence Interval * ## Sharing/Access information * Link to publicly accessible University of Florida Vertebrate Paleontology Database: * https://www.floridamuseum.ufl.edu/vertpaleo-search/ * Link to Vegan package for R: * https://github.com/vegandevs/vegan ## Code/Software All code was run in R/R Studio (2022) using the Vegan Package (2022). See link above and supplementary files for more details.