carboniferous
adjective
car·bon·if·er·ous ˌkär-bə-ˈni-f(ə-)rəs 
1
: producing or containing carbon or coal
2
capitalized : of, relating to, or being the period of the Paleozoic era between the Devonian and the Permian or the corresponding system of rocks that includes coal beds see Geologic Time Table
Carboniferous noun
Example Sentences
Recent Examples on the Web The clay exterior is filled with spray insulation and impressed with individual scales, which are based off of a 3-D print of a carboniferous plant fossil. 
Washington Post, 19 Jan. 2020 True spiders, to which sea spiders (some of which have more than eight legs) are but distantly related, are known for certain only from as far back as the Carboniferous period, about 300m years ago. The Economist, 13 July 2017 A new microsaur from the Early Carboniferous (Viséan) of East Kirkton, Scotland, showing soft tissue evidence. Darren Naish, Scientific American Blog Network, 7 July 2017
Washington Post, 19 Jan. 2020 True spiders, to which sea spiders (some of which have more than eight legs) are but distantly related, are known for certain only from as far back as the Carboniferous period, about 300m years ago. The Economist, 13 July 2017 A new microsaur from the Early Carboniferous (Viséan) of East Kirkton, Scotland, showing soft tissue evidence. Darren Naish, Scientific American Blog Network, 7 July 2017 Word History
First Known Use
1799, in the meaning defined at sense 1