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Xiphosura

Horseshoe crabs

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taxon links [up-->]Limuloidea extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon extinct icon [down<--]Arthropoda Interpreting the tree
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This tree diagram shows the relationships between several groups of organisms.

The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.

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Relationships after Anderson & Selden 1997.
Containing group: Arthropoda

Other Names for Xiphosura

References

Anderson, L. I. and P. A. Selden. 1997. Opisthosomal fusion and phylogeny of Palaeozoic Xiphosura. Lethaia 30:19-31.

Information on the Internet

Title Illustrations
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Scientific Name Pseudoniscus roosevelti
Reference Illustration from North American Index Fossils, Volume II, A. W. Grabau and H. W. Shimer (eds.), A. G. Seiler & Co., New York, 1910.
Specimen Condition Fossil -- Period: Siluric
Scientific Name Limulus polyphemus
Reference DeKay, J. E. 1843. Zoology of New York or the New-York Fauna, Part VI: The Crustacea. Albany, New York.
Creator Lithograph by George Endicott
About This Page

Page: Tree of Life Xiphosura. Horseshoe crabs. The TEXT of this page is licensed under the Creative Commons Attribution-NonCommercial License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.

Citing this page:

Tree of Life Web Project. 2002. Xiphosura. Horseshoe crabs. Version 01 January 2002 (temporary). http://tolweb.org/Xiphosura/2538/2002.01.01 in The Tree of Life Web Project, http://tolweb.org/

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This page is a Tree of Life Branch Page.

Each ToL branch page provides a synopsis of the characteristics of a group of organisms representing a branch of the Tree of Life. The major distinction between a branch and a leaf of the Tree of Life is that each branch can be further subdivided into descendent branches, that is, subgroups representing distinct genetic lineages.

For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.

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