Hallucigenia Cambrian Period (~530-505 Ma) Thought to be a worm, possibly an early ancestor of velvet worms 1-3 cm long Found in Canada and China

Jaekelopterus Devonian Period (~405 Ma) The largest known species from a group of arthropods called “sea scorpions” or eurypterids Up to 8 feet long Found in Germany

Walliserops Devonian Period (~400-390 Ma) A “trident” bearing trilobite 1-8 cm long Found in Morocco

Tiktaalik Devonian Period (~375 Ma) A lobe-finned fish which represents one of the oldest examples of fish developing adaptations to life on land Its name was suggested by Inuit elders 3 to 9 feet long Found in Nunavut, Canada

Dunkleosteus Devonian Period (~380-360 Ma) A carnivorous placoderm, or “armored” fish Some species grew up to 33 feet long! Found in North America, Poland, Belgium and Morocco

Angiosperm

Lepidodendron Devonian to Triassic Periods (~380-205 Ma) Very common plants of the Carboniferous Period known as “scale trees” Estimated to grow taller than 100 feet Had a nearly worldwide distribution

Arthropleura Mississippian to Permian Periods (~340-280 Ma) A very large herbivorous millipede, which is the largest known land invertebrate ever! 1 to almost 9! feet long Found in North America and Europe

Inostrancevia Permian Period (~260-254 Ma) A large carnivorous synapsid or “mammal-like reptile” from the group called gorgonopsids Up to 12 feet long Found in Northern Russia

Archaeopteryx Jurassic Period (~151-148 Ma) Well-known for being a transitional fossil between dinosaurs and birds Up to a 1.5 foot wingspan Found in Germany

Eomaia Cretaceous Period (~125 Ma) An early mammal that is not truly a placental mammal, but one of the oldest ancestors to display traits of placentals 10 cm (4 inches) in length Found in China

Spinosaurus Cretaceous Period (~112-97 Ma) A piscivorous (fish-eating) theropod dinosaur 40 to 60 feet long Found in Egypt and possibly in Morocco

Parapuzosia Cretaceous Period (~95-70 Ma) A very large species of ammonite, related to animals such as squid and octopus Up to 11 feet in diameter Found in North and South America and Europe

Prognathodon Cretaceous Period (~94-66 Ma) A species of mosasaur, a type of marine reptile Up to 30 feet long Found nearly worldwide

Stygimoloch Cretaceous Period (~66 Ma) A pachycephalosaurid dinosaur whose name translates to “demon dinosaur from the river Styx” 7 to 10 feet long Found in Montana and Wyoming

Titanoboa Paleocene Epoch (~60-58 Ma) The biggest known snake to ever live! Up to 50 feet long Found in Colombia

Teilhardina Eocene Epoch (~56-50 Ma) The earliest known North American primate Less 1 foot long from head to tail Known from Belgium, China, France, and the United States

Amphicyon

Amphicyon Miocene Epoch (~18-2.5 Ma) A carnivorous, bone-crushing mammal known popularly as a “bear-dog” Up to 8 feet long Found in North America, Asia, Africa, and Europe

Platybelodon Miocene Epoch (~15-4 Ma) A species of “shovel-tusker” (or gomphotheres) that is related to elephants Up to 12 feet long Found in Africa, Europe, Asia, and North America

Argentavis Miocene Epoch (~8-6 Ma) One of the largest flying birds to ever live The estimated wingspan is 23 feet…about twice as large as the bird with the largest wingspan today (the wandering albatross)!! Found in Argentina

Megatherium Pliocene to Holocene Epochs (~2 Ma- 10,000 yrs ago) The largest known species of giant ground sloths Up to 20 feet long! Originally lived in South America before emigrating to North America during the Great American Biological Interchange