Cretaceous 42 Cenozoic rocks 43 Tertiary 43 Quaternary 43 Main types of fossils 44 Plant fossils 44 Classification of the plant kingdom 44 Division Thallophyta 44 Division Bryophyta 44 Division Tracheophyta 44 Animal fossils 48 Phylum Protozoa 48 Class Sarcodina 48 Order Foraminifera 48 Order Radiolaria 48 Phylum Porifera 49 Phylum Coelenterata 49 Class Anthozoa 49 Subclass Zoantharia 50 Order Rugosa 50 Order Scleractinia 50 Order Tabulata 50 Phylum Bryozoa 50 Phylum Brachiopoda 54 Class Inarticulata 54 Class Articulata 56 Phylum Mollusca 56 Class Gastropoda 59 Class Pelecypoda 59 Class Cephalopoda 66 Subclass Nautiloidea 66 Subclass Ammonoidea 75 Subclass Coleoidea 78 Order Belemnoidea 78 Phylum Annelida 78 Phylum Arthropoda 78 Subphylum Trilobitomorpha 78 Class Trilobita 78 Subphylum Crustacea 80 Class Ostracoda 80 Phylum Echinodermata 80 Subphylum Pelmatozoa 81 Class Cystoidea 81