An Electronic Key & Field Guide to
        Tardigrades of the Great Smoky Mountains National Park


The Most Important Thing:
This key is made up of multiple subkeys.  To effectively run the key, you must first select the appropriate subkey for your interest.  How to do this is explained in "Using the Key" below.


This is a key and field guide to the Phylum Tardigrada in the Great Smoky Mountains National Park.   It has been developed as part of the All Taxa Biodiversity Inventory (ATBI) ( The key is designed to cover ONLY species in the park, though it includes approximately 70% of the known eastern U.S. limno-terrestrial species (H. Meyer pers. com.).    Using it for specimens from other sites could give erroneous results.  Characters for taxa above the species level are based on a key to limno-terrestrial tardigrades (including Heterotardigrada and Eutardigrada) by Nelson & McInnes (2002) and a key to Eutardigrada by Pilato & Binda (2010).    For a current checklist of all known tardigrade species, and the authorities for each, go to the  Univeristy of Modena Tardigrade Webpage.  In our key, images have been copied from many sources and sometimes modified.  In all cases, the citation for the original illustration is indicated and these citations can be found in the bibliography.

Getting Started:

Looking at the Species:

Using the Key:

Subsets Dialog

You must always select a feature (character) subset and its corresponding entity  (species or higher taxon) subset.  A normal progression would be to start with “Class Characters” and “Classes”.  If you determine that your specimen is a eutardigrade, you could then go to the “Eutardigrade Genera Characters” and “Eutardigrade Genera” subsets.   Once you have figured out the genus, then you can select the appropriate genus characters and genus subsets.  If you immediately know the genus, then you can go directly to those subsets:  e.g. if you already know you have a Pseudechiniscus then select “Pseudechiniscus Characters” and “Pseudechiniscus.”  Each time you start a new subset you must reset the key Restart key icon .

Click here to start the key.
Start the Key


  1. Data on habitat associations and abundance listed in species accounts are based on data analyzed as of 15-Oct-2011, including over 15,000 specimens examined and entered in the ATBI database.
  2. Data on abundance listed in species accounts uses the following categories:
  3. Funding for this project was provided by Discover Life in America (, Warren Wilson College ( and the Environmental Leadership Center of Warren Wilson College (
  4. This key and all original images are copyrighted by Paul J. Bartels and Diane R. Nelson.  Please do not use images without permission.


Paul Bartels
Warren Wilson College
Depts. of Biology & Env. Studies
PO Box 9000
Asheville, NC 28815
[email protected]
Paul Bartels
Diane Nelson
East Tennessee State University
Dept. Biological Sciences
East Tennessee State Univ
Johnson City, TN 37614
[email protected]
Diane Nelson

© P.J. Bartels & D.R. Nelson 2011