Scientists aim to describe a single 'tree of life' that reflects the evolutionary relationships of living things. However, evolutionary relationships are a matter of ongoing discovery, and there are different opinions about how living things should be grouped and named. EOL reflects these differences by supporting several different scientific 'classifications'. Some species have been named more than once. Such duplicates are listed under synonyms. EOL also provides support for common names which may vary across regions as well as languages.

Preferred marks the preferred classification for this taxon.

Recognized By Rank Classification
Integrated Taxonomic Information System (ITIS)
view in classification
Species Import
BOLDS images II Species
BOLDS resource for species-level taxa
  • Equus ferus przewalskii
EOL Group on Flickr
EOL Group on Flickr
EOL Group on Flickr
IUCN Red List
Animal Diversity Web Descriptions
Monthly ARKive text import
Milk Chemical Data Species
NCBI Taxonomy
view in classification
Paleobiology Database
view in classification
IUCN Structured Data
US Fish and Wildlife Service Endangered Species Program resource
  • Equus przewalskii
Wikimedia Commons
iNaturalist Images Subspecies


EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

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