13. Baiera. A fossil leaf genus of ginkgo, whose only living representative is the species Ginkgo biloba, saved from extinction by careful cultivation in China. Several specimens of this “living fossil” were presented to this country by the Chinese and are now flourishing on many college campuses, including that of the University of Illinois. After Mägdefrau.
14. Cordaites. After Grand Eury.
15. Lebachia. A “transition conifer,” forerunner of present day conifers. After Mägdefrau.
16. Pinus. Modern pine. After Mägdefrau.
17. Acer. Common maple, an angiosperm whose leaves are also found among Tertiary fossils. After Mägdefrau.
18. Rosa. The prairie rose, an angiosperm.
19. Campsis. Trumpet vine, an angiosperm.
Geologic Time Chart
Time Units Era and Years CENOZOIC “Recent Life” Pleistocene Pliocene Miocene Oligocene Eocene Paleocene MESOZOIC “Middle Life” Cretaceous 70 million herbaceous lycopods Jurassic 25 million yellow-green algae selaginellids Triassic 30 million cycad-like plants Equisetum PALEOZOIC “Ancient Life” Permian 25 million transition conifers pines, spruces, firs, etc. Equisetites Pennsylvanian 25 million ferns related to modern families bryophytes Mississippian 30 million seed ferns calamites cycads Devonian 55 million cordaites sphenophyllids ancient ferns Silurian 40 million psitopsids Foerstia Ordovician 80 million red algae green algae Cambrian 80 million PROTEROZOIC and ARCHAEOZOIC ERAS 4½ billion years blue-green algae chemosynthetic bacteria? NO CERTAIN FOSSILS KNOWN Plants Algae yellow-green algae brown algae red algae green algae blue-green algae Mosses bryophytes Foerstia Vascular Plants “Whisk Ferns” psitopsids Club-mosses scale and seal trees quillworts herbaceous lycopods Scouring Rushes, Horsetails Equisetites Equisetum calamites selaginellids Ferns and Seed Plants Ferns ancient ferns ferns related to modern families Gymnosperms Cycads seed ferns cycads cycad-like plants Ginkgo Conifers cordaites transition conifers pines, spruces, firs, etc. Flowering Plants