Fossil- any evidence of former life. (species that are no longer present)
(e.g. petrified wood, fossilized bones, insects preserved in amber etc.)
I. Fossil Record
 B. >99% Extinction- or 99% or higher number of species of organisms should be extinct.
C. Fossils found "where they shouldn't be." Like fossils of marine animals on mountain peaks.
D. Fossils laid down in order from simple to complex. (bacteria fossils-simple aquatic animals-fish-land plants-amphibians-reptiles-dinosaurs-mammals-birds)
E. History of our planet.
Cladogram of the Vertebrates( Animals with spinal columns) This shows how animals are connected, evolutionary speaking (fish to reptiles to birds and also reptiles to mammals. Mammals came before birds.)
 1 Fish       2 Amphibians        3 Reptiles      5 Birds       4 Mammals
     i              i                        i                    i                  i
      i              i                iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
         i          i  i               
               i    
Note: the i's don't really mean anything they just connect the animals)
Fish-Ectothersm (require an outside source of heat to function), have fish scales, external fertilization, gelatinous eggs.
Amphibians- Ectotherm, no body covering, external fertilization, gel eggs.
Reptiles-Ectotherm, have reptile scales (very different from fish scales, internal fertilization, amniotic (shell wtih amniotic fluid  surrounding the embryo) egg.
Birds-Endotherm (generate heat from the inside), have feathers, and scales (think of a birds feet), internal fertilization, amniotic egg.
Mammals-Endotherm, have hair, internal fertilization, Amniotic eggs (not very many, like platypuses, and echidnas nowadays), Marsupials-kangaroos, koalas, and other mammals with pouches (embryos of marsupials have a yoke while they are in the mother), and Placental mammals(all of the other mammals).