21. Climate change devastated these tropical rainforests during the Carboniferous period . 22. Terrestrial life was well established by the Carboniferous period . 23. Some members of this family attained tree-like stature during the Carboniferous Period ( around ). 24. During the Carboniferous period , the Mackay areas were underwater and home to diverse marine wildlife. 25. The term is also sometimes applied to animals ( usually dragonflies of the Carboniferous period . 26. The oldest geological formation in the valley is the Supra-Pennant Measures of the Carboniferous period . 27. The soil is composed by sandstone from the Carboniferous period , of fluvial and glacial origin. 28. A black limestone containing fossil corals of the Carboniferous Period , some 325 million years ago. 29. The rocks underwent considerable folding during the Carboniferous period . 30. Cockroaches have remained substantially unchanged since the Carboniferous period more than 300 million years ago.