DOI: 10.5061/dryad.kh18932fk
title: Data from: Trechus (Coleoptera: Carabidae) of Appalachia: A phylogenetic insight into the history of high elevation leaf litter communities

description: Elevation gradients provide a wealth of habitats for a wide variety of
 organisms. The southern Appalachian Mountains in eastern United States are
 known for their high biodiversity and rates of endemism in arthropods,
 including in high-elevation leaf-litter taxa that are often found nowhere
 else on earth. Trechus Clairville (Coleoptera: Carabidae) is a genus of
 litter inhabitants with a near-global distribution and over 50 Appalachian
 species. These span two subgenera, Trechus s. str. and Microtrechus
 Jeannel, largely restricted to north and south of the Asheville basin,
 respectively. Understanding the diversification of these 3–5 mm flightless
 beetles through geological time can provide insights into how the
 litter-arthropod community has responded to historical environments, and
 how they may react to current and future climate change. We identified
 beetles morphologically and sequenced six genes to reconstruct a phylogeny
 of the Appalachian Trechus. We confirmed the Asheville Basin as a
 biogeographical barrier with a split between the north and south occurring
 towards the end of the Pliocene. Finer scale biogeography, including
 mountain-range occupancy, was not a reliable indication of relatedness,
 with group ranges overlapping and many instances of species-, species
 group-, and subgeneric sympatry. This may be because of the recent
 divergence between modern species and species groups. Extensive taxonomic
 revision of the group is required for Trechus to be useful as a
 bioindicator, but their high population density and speciose nature make
 them worth additional time and resources.
description: The data set is a nexus formatted file of aligned molecular
 sequence data from 6 regions of five genes: 28S, Wingless, CAD,
 Topoisomerase, 18S, and COI (2 fragments). The barcoding region of COI was
 sequenced using Illumina and Nanopore multiplexed next-generation
 sequencing techniques. The other markers were sequenced through standard
 Sanger sequencing. Sequences were quality-filtered using BBTools and
 ONTBarcoder, base-checked in Geneious, and aligned using MAFFT. 
description: # Trechus (Coleoptera: Carabidae) of Appalachia: A Phylogenetic Insight
 into the History of High Elevation Leaf Litter Communities
 [https://doi.org/10.5061/dryad.kh18932fk](https://doi.org/10.5061/dryad.kh18932fk) The data set is a nexus formatted file of aligned molecular sequence data from 6 regions of five genes: 28S, Wingless, CAD, Topoisomerase, 18S, and COI (2 fragments). The barcoding region of COI was sequenced using Illumina and Nanopore multiplexed next generation sequencing techniques. The other markers were sequenced through standard Sanger sequencing. Sequences were quality filtered using BBTools and ONTBarcoder, base-checked in Geneious, and aligned using MAFFT. It includes a total of 430 Carabidae (ground beetle) taxa (some obtained from GenBank from previously published studies), primarily from the supertribe Trechitae, and 5988 nucleotide positions (28S = 1-1260; wg = 1261-1716; CAD4 = 1717-2541; Topo = 2542-3283; 18S = 3284-5329; COI = 5330-5988. ## Description of the data and file structure Nexus formatted files are readable by many common phylogenetic analysis packages, including PAUP, Mesquite, MrBayes, or IQTree, among others. ## Sharing/Access information These data (unaligned) are also available on GenBank ([https://www.ncbi.nlm.nih.gov/nuccore/?term=trechus+Caterino)](https://www.ncbi.nlm.nih.gov/nuccore/?term=trechus+Caterino\)) #