graptolite
graptolite
[ˈgraptəlʌɪt]
noun
[ˈgraptəlʌɪt]
noun
- a fossil marine invertebrate animal of the Palaeozoic era, forming mainly planktonic colonies and believed to be related to the pterobranchs
笔石 - Class Graptolithina, phylum Hemichordata
笔石纲，半索动物门
- mid 19th cent.: from Greek graptos 'marked with letters' + -lite: so named because of the impressions left on hard shales, resembling markings with a slate pencil
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