Helping School Librarians Understand Dewey 590 Animals

Many School Librarians are confused by the organization of Animals in 590 Science. This School Librarian/Science Teacher explains Dewey's disciplinary numbering based on biology's scientific nomenclature! | No Sweat Library

I love organizational patterns, and cataloging was one of my favorite courses when getting my Master of Library Science degree. I love the Dewey Decimal Classification System because it’s flexible and continually adapts to changes in our society and culture.

Before I became a School Librarian I taught secondary science—biology, chemistry, and physical science. Science has wonderful organizational structures for our natural world—chemistry’s Periodic Table of the Elements is my favorite.

Naturally, the 500s are my favorite Dewey numbers, so when a colleague asked if I could explain the reasoning behind the Dewey Decimal Classification of animals in the 590s, I was delighted to help! I hope all School Librarians will learn from this “deep dive” into a biology section of the Dewey 500s.


The Dewey Decimal Classification System organizes topics according to discipline, that is, the field of study, so animals, being part of a science discipline, are assigned to the DDC Class of 500 Science, and as living things are assigned to the DDC Divisions of Life Sciences, numbers 570-590. The discipline of biology uses a system for organizing living things called taxonomic classification and scientific nomenclature. From broadest category to most specific, that classification system is:


Within those groupings, biology classifies organisms according to increasing complexity. The DDC follows biology’s disciplinary classification system, so the simplest cellular life and its Kingdoms are in 570, the more complex Plant Kingdom is 580, and the most complex Animal Kingdom is 590. The Animal Kingdom of biology has Phyla which the DDC doesn’t specifically differentiate, but roughly the Dewey numbers are:

  • 592-595 Phyla Invertebrata – for animals that don’t have a backbone.
  • 597-599 Phyla Vertebrata – for animals that do have a backbone.

The DDC section numbers (the ones-place) are equivalent to a biology Class (not to be confused with Dewey Classes) according to the increasing complexity of the organism:

  • 592-595 Invertebrates
    • 593 Class of sponges, coral & starfish
    • 594 Class of clams, oysters, octopi
    • 595 Class of crustaceans & insects

To understand Dewey numbers 596-599, know that the tenths place is assigned to each different biology Order, so by increasing complexity the numbers are:

  • 596-599 Vertebrates
    • 597 Class of cold-blooded vertebrates:
        • 597.1-597.7 Orders of Fishes (sharks are 597.3)
        • 597.8 Order Amphibians
        • 597.9 Order Reptiles

      Dewey number 597

    • 598 & 599 Classes of warm-blooded vertebrates:
      598 Class Birds
      599 Class Mammals with…

      • 599.2 Order Marsupial – Families possum, kangaroo
      • 599.3 Orders of small placental mammals – Families rabbits, rodents (rats & mice), squirrels, beavers
      • 599.4 Order Chiroptera (bats)
      • 599.5 Order Cetacean – Families whales, dolphins, manatees

      Dewey numbers 599-599.5

      • 599.6 Order Ungulates – Families of land-based plant-eating animals (camels, cows, deer, horses, elephants)

      Dewey number 599.6

      • 599.7 Order Carnivora (Families felines, canines, bears, marine carnivores like seals & walruses)
        (You won’t find books here about animal pets such as cats, dogs, or birds; DDC assigns pet books to 636 Domestic animals.)
      • 599.8 Order Primate (monkeys, baboons, orangutan, gorilla, chimpanzee)

      Dewey numbers 599.7-599.8

      • 599.9 Order Hominids—that’s us.
        You rarely have 599.9 books, because books on humans are usually about the human body and are located in 610 Medicine & health.

Keep in mind that with Dewey numbers, a book covering multiple groups is assigned the lowest and least specific Dewey number. A book about American large animal wildlife with wolves and mountain lions would be numbered 599.7 and shelved with other carnivore books; if the book also included moose and elk, then it would be numbered 599 and shelved with other mammal books. If you’re looking for books for a class assignment, you might need to look beyond just one specific Dewey number or do an online catalog search by Subject to pick up any relevant books outside of a specific number.


Join Life Science with Dewey Subjects for an Authentic Classification Lesson - Enhance student comprehension of life science classification with a Library Lesson on Dewey Decimal Subject Numbers for animals! Here's how to do it... | No Sweat LibraryHere’s a Library Lesson I used with my middle school Life Science classes using Dewey Decimal Subjects to enhance student understanding of taxonomic classification. To prepare for this lesson I pull books from shelves so there is a sample of the various kingdoms, phyla, orders, etc. with about 6-8 books per table (seating 4 students).

To begin the lesson, I give these 6g students a classification of living things taxonomy chart worksheet, based on what they study in class, which stimulates student participation during Direct instruction. During the Modeling & guided learning activity, students hierarchically organize the books on their table and fill in boxes on their worksheet with Dewey numbers and the animal subjects of the books.

There are a few empty boxes left, so for Independent practice, students visit the Science 590-599 bookshelves to find one book whose Dewey number and subject fills in an empty box on their worksheet. They return to the table and work with their table partners to fill in any empty boxes.

Students paste the daily-grade worksheet into their Interactive Notebook (graded later by their teacher), then they can browse for a book to check out. I see that students apply what they learn as they explore other topical sections of the Science shelves, as well as the 636 section on domesticated animals and pets.

I have a similar lesson for 6g on ecology, for 7g on human body systems, and for 8g on weather and weather disasters. As middle school Science has become more integrated, these quick Library Lessons offer single-visit reinforcement for a variety of Science topics at any grade-level, and also give students more insight into and experience with the different Dewey Subjects in the library. As always, teachers love that I have a graphic organizer worksheet to use as a daily grade.

line of books laying down - indicates end of blog article

Make it easier for students to find a Dewey book in your school library with these colorful, pictorial signs and shelf labels. They're just what you need for your middle school or elementary library!


If you like the colorful shelf labels above, you can find them in my TPT store, No Sweat Library!


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