<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">Ordovician</topic></authority><related type="other"><topic>Cambrian</topic></related><related type="other"><topic>Silurian</topic></related><related type="broader"><topic>Paleozoic</topic></related><variant type="other"><topic>Ordovician Period</topic></variant> <note xml:lang="en"><![CDATA[ The second period of the Paleozoic, following the Cambrian and preceding the Silurian. It extends from about 448 to 443 million years ago. It is marked by a significant radiation of marine life and the first colonization of land, by nonvascular plants. ]]></note></mads>