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Design of Tree of Life Leaf Pages

Usually, species are the terminal taxa of the ToL as a whole. Therefore, leaf pages generally are those ToL pages that are dedicated to individual species. If you subdivide your group into subgroups below the species level, then your species pages are branch pages, of course, and your leaf pages may represent subspecies, varieties, or strains. The major difference between a leaf page and a branch page is that leaf pages do not contain a phylogenetic tree. The group represented by a leaf page cannot usually be subdivided into subgroups (at least not with any confidence). So once we have arrived on a leaf page, navigation up the ToL to finer levels is not possible. Since leaf pages do not serve as traffic pointers to other parts of the Tree of Life, they have fewer restrictions on their format than do branch pages, but there still are some requirements.

This page gives an outline of our expectations of the content and format of the different sections of a ToL leaf page. For more general issues relevant to ToL page design, please also have a look at Tips & Guidelines for ToL Page Authors.

Components of a ToL Leaf Page:

Page Status

The status of a leaf page is indicated in the upper right corner of the white content box. All pages start out as temporary pages, and higher page status levels are assigned by a ToL editor or coordinator after the page has been reviewed. See Status of Tree of Life Pages for information about relevant policies.

Titles, Subtitles, Supertitles

The Group Name you enter in TreeGrow's Tree Window or in the ToL Web Tools Taxon Names form will usually be used as the title of your leaf page. The Group Name should generally be the scientific name. Please use the full name of a species, i.e., do not abbreviate the genus name. Always use the most specific scientific name available for a group; i. e., in the case of a monotypic genus, use the name of the species, not the name of the genus as the group name.

You can use subtitles and supertitles to accommodatae other taxon names, e.g., common names or names of higher taxonomic categories (if multiple categories apply to a single node). In addition, you can choose to display author data for names. See Taxon Names for information on how to enter this information and how to get it to show up on a page.

Author Credits etc.

The names of page authors are printed at the top of the page, and their contact information is printed in the About This Page section near the bottom of the page. The authors' names at the top function as links to the About This Page section. Contributors' addresses, emails, and homepage urls are retrieved from the registration data in the ToL database, so page authors don't have to worry about entering these data once a person has been registered. Acknowledgments of funding agencies or people who helped in the creation of a page are also featured in this section, along with statistics about the page's publication and revision history.

Title Illustrations

Each ToL leaf page should contain at least one picture of a representative member or members of the group. Your title illustrations should give the reader a general impression of what the organisms in your group look like. Therefore, they should generally show whole organisms (or substantial portions), not just certain body parts. Good pictures of live specimens are preferred whenever they are available. For some organisms, especially rare or extinct groups, this will not be possible. You can choose to have a single title picture, or you can display several pictures next to one another. For general information about finding and processing images for ToL pages, please have a look at Illustrations for Tree of Life Pages.

Moving the cursor over a title image will pop-up a floating box containing information about this image (in javascript enabled browsers only). Also, title images are linked to the Title Illustrations section near the bottom of the page. In this section thumbnails of the title images are displayed alongside image data and/or a custom caption written for the given title image array.

Text Sections

ToL leaf pages feature two standard text sections: Introduction and Characteristics. A complete leaf page should feature both of these sections. Authors can create additional text sections focussing on important aspects of an organism's biology. Text sections can be illustrated with images, but only include images that have a clear relationship to the text. Also, please be sure to add a caption for each image.

Sometimes ToL authors inquire about including text on their ToL pages that has been previously published or that they wish to publish elsewhere in the future. If you consider using such text on your page, make sure to look at the page on copyright issues.


The Introduction should introduce the members of your group. What kinds of organisms are they, what is unique about them, and in what context might the reader have encountered these organisms before? You might talk about geographic distribution, relationship to humans, habits of the organisms, habitats, etc.

The Introduction should not include extensive discussions of any particular topic, and it should be kept relatively brief. If you want to include more information about a particular topic, consider placing it in a separate section. Generally, one to four paragraphs are appropriate for most groups of organisms.

Furthermore, this section should be easy to read (target an educated layman). The Tree of Life project is used a lot in middle and high schools, so we want at least a few sections near the top of the page that can be read by non-biologists.


The Characteristics section generally follows immediately after the Introduction. It should talk about the general characteristics of the members of the species. Diagnostic information that would allow identification of the species should be included. You can also describe some of the unique structural or ecological features, perhaps including a small picture or two. The start of the Characteristics section should be easy to read (target an educated layman), but in later paragraphs it can digress into jargony details for the biologist.

Other Topics: Custom Text Sections

Leaf page authors can erect additional text sections according to the special requirements of their group. Such additional topics may provide information about biogeography, life history, life cycle, fossil specimens, topics relating the organisms to humans (e.g., medical importance, economic importance), or information about the location, condition, etc. of type specimens. If information about the conservation status of a species is available, we recommend that you include a section on this topic.

In order to keep leaf pages at a manageable size, custom text sections should not be too long, and there should not be too many of them on any given page. Also, leaf pages should not take too long to load in a browser, so large illustrations should be avoided. If you would like to provide detailed information (i.e., more than three or four paragraphs) or large media files for any particular topic, or if there are many different topics worth covering for your group, you should consider creating scientific articles or notes for some of your topics.

References & Internet Links

The References section should contain the bibliographic references for your group. These should follow the format used in the journal Systematic Biology. The references should include not only cited papers, but also other general references about the group.

The Information on the Internet section provides links to other internet sites that contain information about your group. We request that you generally list only those links that focus exclusively or extensively on your group; i.e., a site about "Australian Mammals" should be listed on the Mammals page and on the Marsupialia page, but there is no need to repeat this link on the ToL page of every single kangaroo species. Of course, if the site has a nice page about a certain kangaroo species, then there can be a deep link directly to this page from the ToL page of that species. If you come across good web sites that should be featured on ToL pages that you are not in charge of, you can always send us a suggestions to include these links on other people's pages.

Please note that the Information on the Internet section is subject to editorial revisions without notice. We may occasionally check and update the links in this section, and we may also add relevant links that we come across or that are sent to us by other people. If we ever add a link that you would rather not have on your page, please send a request to remove it to

The Right Sidebar

The right sidebar of a ToL branch page contains a table of contents for the current page as well as links to other ToL pages providing information about the current group and related groups. For a detailed explanation of the links contained in the sidebar, refer to Navigating the Tree of Life. All of the links in the sidebar are created automatically based on the relationships between taxa in the ToL database and attachments of objects such as articles, notes and treehouses to nodes in the tree.

Example Pages

Here are some ToL branch pages that new authors can use as models for building their own pages:

Contribute to the ToL

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