<?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">Protochordata</topic></authority><related type="narrower"><topic>Tunicata</topic></related><related type="narrower"><topic>Vertebrata</topic></related><related type="broader"><topic>Chordata</topic></related><variant type="other"><topic>protochordate</topic></variant><variant type="other"><topic>protochordates</topic></variant> <note xml:lang="en"><![CDATA[ Group of marine animals characterized by having at some point in their life cycle a hollow dorsal nerve cord, a notochord, and gill slits, including hemichordates, urochordates, cephalochordates, or any hypothetical ancestral form of any of these. The protochordates lack a skull and vertebrae and are believed to resemble the ancestors of the vertebrates. They include the subphylums of Tunicata and Cephalochordata. ]]></note></mads>