Diatom(s) of the Month - November 2017: the recently-digitized Diatom New Taxon File (DNTF) at the Academy of Natural Sciences

by Alison Minerovic*

What is the “DNTF”?
The Diatom New Taxon File, or “DNTF”, is a digitized card catalog of all published diatom names, along with original descriptions, images, and literature citations of taxa published since 1933. It serves as a resource for diatom scientists, taxonomists, systematists, students, and enthusiasts!

Figure 1. DNTF Homepage (from 25 September 2017).

The original card catalog lives in the Diatom Herbarium at the Academy of Natural Sciences in Philadelphia (ANSP), Pennsylvania, USA. Although we no longer add physical cards to the DNTF, Herbarium staff manage and update digital “cards” through our website: http://symbiont.ansp.org/dntf/ (Fig. 1).

Why is the DNTF important?
As many of you know, diatom taxonomy – names, descriptions, and classification – is continually changing. Projects like the DNTF are important for maintaining consistent taxonomy, which forms the foundation of all applied diatom research. For example, systematists seek to determine evolutionary relationships between described taxa. In ecology, analysts use taxonomy to identify communities of modern and/or fossil diatoms, which all have specific environmental preferences. These data are used to develop and apply water quality metrics using diatoms as bioindicators, and reconstructing past conditions in paleoecology using diatom-based transfer functions. With tens of thousands of diatom taxa described, it is difficult to keep track of current names without good record keeping!

History of the DNTF
Dr. Ruth Patrick (Fig. 2), founder of the ANSP Diatom Herbarium, established the DNTF in the early 1950s in order to create a single, centralized diatom taxonomic reference. Prior to the establishment of this file, Frederick William Mills compiled the comprehensive 21-volume encyclopedia of diatom genera and species names, known as the “Mill’s Index”, which covered taxon names published between 1816 and 1932. The DNTF includes all (well, most…) published names, exclusive of those found in Mill’s Index, up to ~2013 when digitization efforts first began.
Figure 2. Dr. Ruth Patrick, ANSP Diatom Herbarium and DNTF founder.

ANSP Diatom Herbarium staff, including Peggy Henderson, Su-Ing Yong, and the Herbarium’s former curator, Dr. Charlie Reimer, pictured below (Fig. 3), diligently maintained the catalog and produced most of the File’s cards until ~2003. From 2003-2007, staff in the ANSP Patrick Center for Environmental Research’s Phycology Section maintained the DNTF. Since 2008, the DNTF has been under the care of the ANSP Diatom Herbarium.
Figure 3. ANSP Diatom Herbarium staff. From left to right: Margaret "Peggy" Henderson, Dr. Charlie Reimer, Su-Ing Yong.

Every five years, an external committee of three diatom researchers reviews the progress of the DNTF. In 2013, the committee recommended the card catalog become digitally and publicly available on the web, despite its founder’s wishes that it remain as a physical file indefinitely. In her opinion, a card catalog in the ANSP Diatom Herbarium was more useful to researchers worldwide, as not everyone had access to computers. Of course, times have changed, and so in 2015 we began organizing existing and newly digitized DNTF cards for our web project. Dr. Marina Potapova (Curator, Fig. 4), Jana Veselá (former Collection Manager), and Chelsea Smith (former Curatorial Assistant) spearheaded the effort, with tireless help from Drexel University co-op students, volunteers, and our Database Manager, Steve Dilliplane. We are happy to present a nearly complete digitized DNTF to the international diatom community!
In 2015, Dr. Marina Potapova (Curator), Jana Veselá (former Collection Manager), and Chelsea Smith (former Curatorial Assistant) spearheaded the DNTF web project. In under two years, and with tireless help from Drexel University co-op students, volunteers, and our Database Manager, Steve Dilliplane, we have finished a “first draft” of our digital card catalog.
Figure 4. Dr. Marina Potapova with the original DNTF card catalog.

How to use the DNTF website
All digitized cards will contain some or all of the following information, on a single- or double-sided index card.
Figure 5. Information on a typical DNTF card.

Figures 6 (left – front) and 7 (right – back). Example DNTF card, "Licmophora flabellata var. spathulata Tsumura".

Currently, there are three ways to navigate our website. The first is through a “Quick Genus Browse” alphabetical toolbar, located on our homepage. The other two options are located in the navigation toolbar on the left-hand side of the homepage, “Search Collection” and “Browse Collection”. The “Search Collection” feature offers advanced search options (e.g. authority, infraspecific epithet, etc.); the “Browse Collection” feature returns stacked folders of genera and nested species, arranged alphabetically; and the "Gallery" feature gives the opportunity to screen cards with hundreds of drawings and/or photos. 

As you begin using this site, you may notice that not all names have cards. Those that do will have an icon next to their name. In most cases, this is intentional; while the File only contained cards for taxa described after the Mill’s Index, this website contains ALL published names. You may find taxa published after Mill’s Index that should have a card. If you do, please let us know! We realize the DNTF is incomplete and we are working to fill in these gaps.

"I would like to provide feedback/criticism/suggestions for improvement. How can I get in touch?"

We welcome your feedback! Please contact us via email at ans_diatomherbarium@drexel.edu with any comments, praises, gripes, and especially any notifications of missing or incorrect taxon cards!

*Collection Manager, Diatom Herbarium, The Academy of Natural Sciences of Drexel University, Philadelphia, PA

Mills F.W., 1932–1935 — An Index to the Genera and Species of the Diatomaceae and their Synonyms. LondonWheldon & Wesley1726 p.


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  2. Digitizing has changed the world drastically in which we are living these days. Everything is now digital and a must have in our daily lives. Thanks for sharing details of digitized diatom of 2017.


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