Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.


Trilobites laid eggs


The discovery that extinct marine organisms called trilobites laid eggs provides the first direct evidence for how they reproduced.

Credit: Yale Peabody Museum/CC0 1.0

Trilobites lived between 520 million and 250 million years ago, and are one of the earliest known groups of arthropods (invertebrates, including modern insects, with exoskeletons and segmented bodies). Thomas Hegna of Western Illinois University in Macomb and his colleagues report the discovery of ancient trilobite eggs in New York State, in rocks about 450 million years old. The eggs are spherical, almost 200 micrometres in diameter, and lie near several well-preserved trilobite fossils (pictured).

Trilobites may have released eggs and sperm through genital pores at or near the backs of their heads, the authors say.

Geology 45, 199–202 (2017)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Trilobites laid eggs. Nature 541, 263 (2017).

Download citation


Quick links