References in periodicals archive ?
Until now, the oldest shark remains had hailed from the Silurian period, some 25 million years younger.
Dudley's ancient fossil history dates back 420 million years to the Silurian period.
The fossils come from the city of Ludlow in Shropshire, England, where they were embedded within rocks from Earth's Silurian period, report Andrew J.
13]C excursions followed at the beginning and top of the late Pridoli with a continuation into the Devonian, evidencing that the carbon cyclic development had become labile again by the end of the Silurian Period.
The first land animals appear in the fossil record at the end of the Silurian period and the beginning of the Devonian period, roughly 400 million years ago.
Donald Mikulic of the Illinois State Geological Survey in Champaign and co-workers report in the May 10 SCIENCE on the discovery of 15 different types of soft-bodied animals dating back 430 million years to the Silurian period.
The Ice Age occurred in the Ordovician and Silurian Periods of geological time (part of the Early Palaeozoic Era), an interval that witnessed a major diversification of early marine animals including trilobites and primitive fish as well as the emergence of the first land plants.