|_Radiata_--Anthozoa |Algae. | | (coral animals), | | | Echinodermata | | | (sea stars, etc.). | | |_Mollusca_--Polyzoa, | | | Tunicata. | | |Other Mollusks and | | | Articulates as before. | | | | |Upper Silurian. |Radiates, Mollusks, and |Acrogenous | | Articulates as before. |Land plants. | |_Vertebrata_--First | | | Ganoid and Placoid | | | Fishes. | | | | |Erian or Devonian. |_Articulata_--Insects |Acrogens | | and higher Crustaceans. |and | |_Vertebrata_--Fishes, |Gymnosperms. | | Ganoid and Placoid. | | | | |Carboniferous. |_Mollusca_--Pulmonata |Acrogens, | | (Land Snails). |Gymnosperms, | |_Articulata_--Myriapods, |Endogens? | | Arachnidans (Gallyworms,| | | Spiders and Scorpions). | | |_Vertebrata_--Batrachians| | | or Amphibians prevalent.| | | | |Permian. |_Vertebrata_--Lacertian | | | or Lizard-like | | | Reptiles. | -------------------------------------------------------------------- III. |Triassic. |_Vertebrata_--Higher | SECONDARY| | Reptiles prevalent; | OR | | Marsupial Mammals. | MESOZOIC | | | PERIOD. |Jurassic. |_Vertebrata_--Great |Endogenous | | prevalence of higher |trees. | | Reptiles; Fishes, | | | homocerque; Earliest | | | Birds. | | | | |Cretaceous. |_Vertebrata_--Decadence |Angiospermous | | of reign of Reptiles; |Exogens. | | Ordinary Bony Fishes. | -------------------------------------------------------------------- IV. |Eocene. |_Vertebrata_--Mammals |Exogens