About MDD

Overview

Development for the Mammal Diversity Database (MDD) is funded primarily by the American Society of Mammalogists (ASM; 2017-present), with logistical and planning support provided related grants at different time points (2025-present: NIH R35 to Upham; 2021-2023: NIH R21 to Upham, Reeder, Sterner, Sen; 2017-2019: NSF Vertlife Terrestrial grant).

The ASM Biodiversity Committee compiles and maintains MDD, an updatable online database of mammal taxonomic and biodiversity information hosted by ASM at https://mammaldiversity.org/. This database aims to provide the latest information on species-level and higher taxonomic changes, thereby promoting more rigorous study of mammalian biodiversity worldwide. The initial objective has been to aggregate, curate, and compile, new citations on species descriptions and taxonomic revisions into regular releases that are downloadable in comma-delimited format. Downstream goals include expanded hosting of ecological, trait, and taxonomic data. Overall, this initiative aims to promote the ASM’s role as a leader in high quality research on mammalian biology.

Curation team

Nate Upham

Chair, Biodiversity Committee

Arizona State University

Connor Burgin

Student Taxonomic Curator

University of New Mexico

Jane Widness

Student Research Assistant

Yale University

Madeleine Becker

Student Research Assistant

George Mason University

Heru Handika

Student Web Developer

Louisiana State University

Jelle Zijlstra

Volunteer Research Assistant

Hesperomys Project

David Huckaby

Chair, Mammal Images Library Committee

California State University, Long Beach

Oversight by the ASM Biodiversity Committee

E. Abreu, J. Alston, T. Androski, M. Becker, C. Burgin, C. Calderón-Acevedo, J. Colella, E. Craig, G. D'Elia, T. Demos, J. Esselstyn, P.-H. Fabre, A. Feijó, A. Ferguson, J. Frey, K. Gorman, M. Hawkins, V. Hayssen, S. Hess, A. Hinckley, D. Huckaby, B. Kohli, T. Lee, S. Liphardt, S. Maher, V. Mathis, M. McDonough, S. Mech, P. Moehlman, A. Mychajliw, J. Nations, R. Norris, G. Oliver, C. Parker, B. Patterson, N. Pradhan, D. Reeder, M. E. Rodríguez-Posada, L. Ruedas, B. Tanis, H. Taylor, N. Upham (chair), J. Widness, J. Zijlstra

Citing MDD

The current database (via Zenodo):

A specific entry: Each entry has a citation string at the end. For example:

Describing the MDD v2.0 taxonomy:

Describing the MDD v1.0 taxonomy:

Taxonomic overview

The Mammal Diversity Database (MDD), originally released in 2018, aims to provide a continuously updated listing of the world’s mammal species and higher taxa (all ranks above the species level). The primary goal of the MDD is to centralize information regarding the most recent and reliable systematic publications for each clade, offering up the taxonomic consequences of those works with a limited amount of subjective curation on behalf of the MDD Team. Foremost, the MDD aims to adhere to open science principles by providing streamlined access to the compiled data from our taxonomic curation efforts.

The MDD includes webpages for each species of currently recognized mammals, including taxonomic comments regarding changes since the Mammals Species of the World, 3rd Edition (MSW3; (Wilson and Reeder 2005)), and fields for type locality, higher-level taxonomy, common names, and updated country-level distributions. More fields of information are available in the download of the MDD (ZIP archive with CSV database & metadata). Some species currently also include the original name combination as spelled in the original taxonomic description of that species, original description citations, links to those publications, holotype voucher specimens, and nominal synonyms in a format similar to MSW3. This information is still a work in progress and is primarily under manual curation, so errors of omission or orthography may still be present. The MDD Team is also working on systematically curating synonyms from large publications such as the Mammals of South America and the Taxonomy of Australian Mammals, for which future updates will include compiled information. Subspecies have not yet been addressed here due to their inconsistent historical usages in mammalogy, although future efforts are likely to compile subspecies information for the purposes of species-level synonymy. The MDD is being regularly updated, so users are encouraged to contact the MDD team to report errors, new taxonomic arrangements, or queries regarding the taxonomy and interface via email: mammaldiversity [at] gmail [dot] com.

Subjective decisions.— In situations of conflicting taxonomic arrangement in the recent literature, the MDD team has endeavored to provide justifications and citations for the subjective decisions made, as well as a ‘flag’ designation in the CSV file. If the reader finds additional situations or omitted evidence, we kindly request feedback (please use the email noted above). The most substantial subjective decision the MDD has thus far encountered has been how to incorporate the recommendations of Groves and Grubb (2011)’s compendium Ungulate Taxonomy. This taxonomy of Perissodactyla and non-cetacean Artiodactyla was fully included in the initial release of the MDD (Burgin et al. 2018). However, since Groves and Grubb (2011) was based primarily on qualitative morphological diagnoses with small sample sizes, it has since become controversial in the mammalogical community (e.g., (Holbrook 2013; Gutiérrez and Garbino 2018)). Many specialists have subsequently reverted to the taxonomic arrangement presented by Peter Grubb in MSW3. In current versions of the MDD, we use MSW3 as a baseline for ungulate taxonomy, leaving out all changes made by Groves and Grubb (2011) with the exception of those supported by other published research.

Additional subjective decisions have been made in collaboratoration with the Global Bat Taxonomy Working Group of the IUCN SSC Bat Specialist Group to promote harmonization between the MDD and batnames.org, as follows:

1. Status of Myotis keenii was re-affirmed on the basis of insufficient evidence for including it as a subspecies or junior synonym of Myotis evotis: Upham, N. S. and Francis, C. M. on behalf of the Global Bat Taxonomy Working Group of the IUCN SSC Bat Specialist Group (2022). On the taxonomy of Myotis keenii and Myotis evotis. Zenodo. https://doi.org/10.5281/zenodo.7336341
2. Myotis lucifigus includes alascensis, carissima, pernox, and relictus as subspecies/junior synonyms given the current lack of conclusive evidence regarding the genetic distinctiveness of those subunits: Francis, C. M. and Simmons, N. B. on behalf of the Global Bat Taxonomy Working Group of the IUCN SSC Bat Specialist Group (2022). On the taxonomy of Myotis lucifugus. Zenodo. https://doi.org/10.5281/zenodo.7338575
3. Recognition of subgenera Lasiurus, Dasypterus, and Aeorestes within the genus Lasiurus: Francis, C. M., N. B. Simmons, V. Van Cakenberghe, N. S. Upham, and C. Burgin, on behalf of the Global Bat Taxonomy Working Group of the IUCN SSC Bat Specialist Group. 2023. On the taxonomy of Lasiurus (v1.0). Zenodo. https://doi.org/10.5281/zenodo.7696845

Higher-level taxonomy.— Regarding higher-level taxonomy (i.e., all ranks above the species level), the MDD maintains an updated listing of all taxonomic ranks traditionally used below the order level as well as major superordinal clades. However, higher-level taxa do not yet have individual webpages, so this information is not yet fully transparent. For future updates, we intend to include individual taxonomic pages for each higher-level taxon in a similar format as the species-level pages. Ordinal names generally follow the arrangement presented in MSW3 with updates based on recent phylogenetic studies, resulting in Soricomorpha + Erinaceomorpha as Eulipotyphla, and Cetacea + Artiodactyla as a united Artiodactyla. The name Artiodactyla is preferred over the name Cetartiodactyla following the recommendation of Asher and Helgen (2010), which recalled the principles of Simpson (1945) to balance prevailing usage with priority in naming higher taxa. Asher and Helgen (2010) also recommended using Lipotyphla over Eulipotyphla, but confusion around the association of Lipotyphla with past definitions of the paraphyletic Insectivora assemblage (Woodman 2018) has prompted the MDD to favor Eulipotyphla as the first name used for the current definition of the order.

Recently extinct species.— The MDD includes all currently extant and wild species, as well as domestic forms and recently extinct species. To be included in the listing, an extinct species must have become extinct (or be expected to have survived) after the year 1500 CE. Extinction codings are informed by data compiled by the International Union for the Conservation of Nature (IUCN) and subfossil records dated from recent strata.

Domestic species.— The MDD lists domestic forms as separate species following the recommendations given in Gentry et al. (2004), which focus on domestication by human artificial selection during ancient times. The primary reason for recognizing domestic forms as distinct species from their wild counterparts is to avoid confusion regarding what forms are being discussed in both political and conservation situations. Recognizing domestic species also provides emphasis on the wild forms as an entity to consider and protect separately. The MDD's focus on artificial selection by humans excludes the self-domestication of humans by natural selection, which has been argued on the basis that modern humans have some of the same genes up-regulated as domestic mammals (see Zanella et al. 2019).

Names described in PhD dissertations.— The MDD treats any scientific names described in PhD or MS theses/dissertations as unpublished unless they have expressly been republished, following this guidance by the ICZN. As a result, any names or types described in theses also need to be published more broadly in order to be considered for recognition in the MDD.

Unavailable names.— The MDD aims to follow the International Code of Zoological Nomenclature (ICZN) strictly. Therefore, we do not include species names that do not fulfill the requirements of the Code, such as names published without a description or in online-only publications without a ZooBank registration. Some names were included in previous versions of the MDD but removed when we realized they were unavailable; these include Maxomys tompotika (removed in version 1.4), Dryomys yarkandensis (removed in version 1.5), and Murina rongjiangensis (removed in version 1.11).

Content goals for improvement

Future activities of the MDD include the following:

• Assembling taxonomic subcommittees. Initial plans have been drawn to assemble experts dedicated to specific mammal clades to collectively provide regular updates and content additions to portions of the MDD taxonomy. This more distributed system of updates by subcommittee will still retain the emphasis upon objective curation based on the published literature, and will develop as the MDD develops.
• Harmonization of the MDD with existing ASM initiatives. A variety of other ASM activities share a similar mission with the MDD, so the aim is to use the compiled taxonomy here to help keep those efforts up to date. These efforts include joining with the Mammal Images Library (David Huckaby, Chair of the MIL Committee is part of our MDD team) and the ASM journal Mammalian Species, for which it may be possible to link, index, and modernize species accounts dating from 1969-Present.

Other in progress goals:

• Synonyms
• Type specimens. We recognize a key priority of reconciling these recent taxonomic changes in mammals with the museum location of type specimens that pertain to these recognized mammalian species. Our aim is to focus on primary types (holotypes, lectotypes, syntypes, cotypes, and neotypes), and exclude secondary types like paratypes and topotypes.
• Authority full citation & year. This content priority will be especially useful for mammalogists without strong library resources. Our goal here is to provide the DOI and links to digitized open-source materials when available (e.g., via Plazi or the Biodiversity Heritage Library).
• Hyperlinks to new species citations (e.g., in Journal of Mammalogy, Mammalian Biology, Zootaxa).
• Expansion of per-species content to include detailed natural history, ecological, and geographic information (e.g., linkages to Animal Diversity Web).
• Per-species information on phylogenetic position (VertLife tree of mammals).
• Links to genetic sequence data (NCBI, BOLD) and morphological data resources.

References