Research NewsPaleontology

Parsing the Trilobites' Rise and Fall

+ See all authors and affiliations

Science  19 Jun 1998:
Vol. 280, Issue 5371, pp. 1837-1838
DOI: 10.1126/science.280.5371.1837a

You are currently viewing the summary.

View Full Text

Summary

Robert Irion After quickly filling many niches on the ocean bottom in the Earth's first evolutionary flowering during the Cambrian explosion, the trilobites--hardy, shelled arthropods--seemingly slid into a protracted decline and by 250 million years ago had disappeared for good. Now, on page 1922 of this issue, paleontologists report a detailed new survey in which they show that while one group, or fauna, of trilobites faded precipitously during the Ordovician period, the other thrived. A still-mysterious combination of ecology, geographic distribution, and high rates of speciation evidently gave this fauna an evolutionary edge.

Related Content