Earth's Ages RPG (Prehistory)

Triassic Period

Geography and Climate:

The first era of the earth which is made up of: Cambrian Period (542 million years ago): The great explosion of life occurs. Example:

1. Arthropods and Radiodonts (The most abundant) •Trilobites: Paradoxides, Olenellus, Elrathia, Redlichia and Agnostus •Radiodonts (Giant Predators): Anomalocaris canadensis, Amplectobelua, Peytoia, Hurdia and Lyrarapax •Primitive/bizarre arthropods: Marrella splendens, Canadaspis, Waptia, Sidneyia and Kylinxia.
2. First Chordates: Animals with a primitive dorsal cord, precursor to the vertebral column. -Pikaia gracilens -Haikouichthys ercaicunensis (First primitive fish) -Myllokunmingia fengjiaoa -Metaspriggina walcotti
3. "Monsters" of Enigmatic Origin (Lobopods and others) •Hallucigenia sparsa (worm with rigid spines on its back and tubular legs) •Opabinia regalis (five eyes and a flexible proboscis with a clamp) •Wiwaxia corrugata (body covered with armored scales and long spines) •Nectocaris pteryx (organism similar to a primitive squid)
4. Mollusks, Brachiopods and Sponges (Benthic Filter Feeders) They formed the seabed and built the first reef ecosystems •Primitive mollusks: Kimberella, Halkieria and Odontogriphus •Primitive sponges: Choia, Vauxia and the Archaeocyathia (extinct cup-shaped sponges that formed reefs) •Brachiopods (false clams): Lingulella and Obolella.
5. Primitive Worms and Echinoderms Priapulids (burrowing worms): •Ottoia prolifica (predator that lived in the sediment) •Symmetrical echinoderms: Gogia and Helicoplacus (ancestors of starfish and sea urchins). Radical Geography and Climate: -A day lasts 21 hours. (The year lasted 420 days) -No polar ice. (Very warm and arid climate) -Supercontinent Gondwana. (largest continental mass) -Continental Flooding (High sea levels) Extinction at the end of the Cambrian period in which 40% of all life died. Causes: -Global cooling. -Anoxia. -Toxic gases. It leaves the way clear for the Ordovician period.

Ordovician Period:

1. Alpha Predators (Giant Cephalopods) Mollusks evolved massively, becoming the largest hunters on the planet. •Endoceras and Orthoceras: Nautiloid cephalopods with straight conical shells. Endoceras could reach more than 4 meters in length. •Megalograptus: A genus of "sea scorpions" (eurypterids) that hunted in shallow ocean beds.

2. First Vertebrates (Agnathan Fish) The first armored fish without real jaws appeared, our own backbone fish. •Sacabambaspis: Primitive fish with a hydrodynamic body covered by bony plates. •Arandaspis: Another genus of jawless fish with bony plates covering it. •Conodonts: Eel-like creatures with large eyes and tiny teeth, highly specialized for catching prey.

3. Dominant Invertebrates and Filter Feeders: Waters of Gondwana and Laurentia teeming with shelled organisms. Diversified trilobites: Flexicalymene, Isotelus (which exceeded 30 cm in length) •Joint brachiopods: Platystrophia, Rafinesquina and Hebertella. •Bryozoans and Crinoids: Bryozoans (colonial moss animals) appeared in many, while crinoids (sea lilies) formed extensive underwater gardens.

4. First Forms of Terrestrial Life, Non-vascular Plants: •Primitive bryophytes (similar to liverworts and mosses) began to colonize the wet continental shores. •Terrestrial fungi: They worked in symbiosis with the first microalgae and plants to break down rock and create the first biological soils.

Climate and Extremes: -A day lasts 22 hours. (A year lasts 400 days) -Supercontinent at the South Pole. (Gondwana drifted south, accumulating large landmasses) -The great global flood. (Sea level rose drastically, 600 meters more than at present) Extinction: Annihilation of 85% of life. Causes: two major pulses 1 glacial cold, 2 extreme heat. It gave way to the Silurian Period.

Silurian Period: Marine Life: Fish with jaws. •Placoderms: The first jawed fish. Acanthodian or spiny shark. •Eurytherids (Eurypterida): Known as "sea scorpions". Largest marine predators, Pterygotus could measure two meters. •Trilobites: Dalmanites and Calymene. •Brachiopods and Bryozoans: They formed dense banks on the seabed. •Coral reefs: Expansion of tubular and rugose corals, they built immense reefs with sponges (Stromatoporoids) •Nautiloid cephalopods: Mollusks with straight or curved shells that lived in the open sea.

Terrestrial Life (First Colonizers) •Cooksonia: Terrestrial vascular plant. It had simple stems that ended in spore capsules. •Baragwanathia: A more complex vascular plant with rudimentary leaves, it appeared towards the end of the period. •Terrestrial arthropods: First to breathe air. Primitive relatives of centipedes (Myriapods), early arachnids such as Palaeophonus. •Giant fungi (Prototaxites): Massive terrestrial organisms with tree trunk-like structures, measuring up to eight meters in height.

Predators: -Pterygotus anglicus: 2.5 m sea scorpion. -Acutiramus: Eurytherid of 2 m. -Megamastax amblyodus: Largest bony fish 1 m. -Orthoceras: Cephalopod with a conical shell that exceeded one meter in length. -Eurypterus remipes: Sea scorpion of 20-30 centimeters. -Mixopterus kiaeri: 70 cm Eurypterid. -Guiyu oneiros: Bent fin fish, 30 cm. -Palaeophonus nuntius (terrestrial predator): 8 to 5 cm. -Palaeotarbus jerami (Terrestrial predator): A few millimeters in size.

Detritivore/Filter feeder: -Birkenia: 20 centimeters. -Dalmanites limulurus (Scavenger): 5 to 10 cm. -Jamoytius kerwoodi (parasite): 15 centimeters. -Primitive myriapods: 1-5 centimeters.

•Climate: Greenhouse effects and stability. •Geography: Gondwana, Laurasia, Panthalasa Ocean and Tethis Sea. Extinction:

1. Oceanic Anoxia
2. Alteration of sea level.
3. Carbon Cycle.

Devonian Period: Main characteristics of the Devonian •Marine fauna: The first jawed fish appeared, primitive sharks and the gigantic placoderms (armored fish) such as Dunkleosteus. •Conquest of the land: The first tetrapod vertebrates (primitive amphibians such as Ichthyostega) came out of the water. •Terrestrial flora: The first forests with true trees and plants with primitive seeds, stabilizing the planet's soils. •Warm climate: The Earth has a globally warm and dry climate, with an absence of glaciers. •Geography: The continents collided to form two large landmasses: Laurasia in the north and Gondwana in the south.

1. Predators of the Devonian: -Dunkleosteus: Armored fish up to 6 meters long. -Primitive sharks: Stethacanthus (Rarest of all with its spiny, anvil-shaped dorsal fin) Doliodus (First toothed sharks) Artarctilamna (Elongated body similar to an eel) Ferromirum (Small shark with a saw-like tooth on its lower jaw) Xenacanthus (With a long spine protruding from the back of its head and a fin running along its entire back)

• Eurypterids: (Sea scorpions) Pterygotus. -Ammonites and Goniatites: Cephalopods with spiral shells that used tentacles.

2. "Herbivores" -Micro-herbivores: Tiny arthropods. -Detritivores: Primitive millipedes that fed on dead matter.

3. Notable species: -Ichthyostega and Acanthostega: Primitive amphibians. -Tiktaalik: fish with a more complex lung and bone system. -Archaeopteris: First true trees.

•Mass extinction: Causes -Land plants supercharged the sea with nutrients. -Massive algae blooms formed, depleting the water of oxygen. -Forests absorbed CO2, causing global cooling. 75% of marine species died, including armored fish. Giving way to the Carboniferous Period.

Permian Period: Last stage of the Paleozoic Era, 299 and 252 million years ago. Geography and Climate: Supercontinent Pangea, surrounded by the Panthalassa Ocean. There was extreme aridity; the gigantic size of Pangaea prevented rain from reaching the continental interior, creating massive deserts.

The Permian-Triassic Mass Extinction: The period ended catastrophically with the "Great Dying", the most devastating extinction event. Main Cause: Massive and prolonged volcanic eruptions, the "Siberian Traps". Greenhouse Effect: The massive amount of carbon dioxide caused extreme global warming. Ocean Collapse: The waters suffered acidification and a great loss of oxygen. Approximately 95% of marine species and 70% of terrestrial vertebrates disappeared.

Flora and Fauna: Dominant Synapsids: Mammal-like reptiles, such as "Dimetrodon", dominated terrestrial ecosystems. Gymnosperms: In the absence of moisture, Carboniferous spore-bearing ferns retreated before seed-bearing plants. Marine Life: Coral reefs, brachiopods, ammonites, and sharks. 🍖Carnivores: Dimetrodon (with dorsal sail) Inostrancevia (saber-fanged) Eryops (giant amphibian) Titanophoneus (swift predator) Sphenacodon (low crest) Prionosuchus (9-meter amphibian) Lycaenops (agile gorgonopsid) 🌿Herbivores: Edaphosaurus (dorsal sail) Scutosaurus (armored) Lystrosaurus (survives extinction) Moschops (thick skull) Cotylorhynchus (barrel-shaped body and tiny head) Aulacephalodon (burrower) Omnivores and Insectivores: Estemmenosuchus (horned giant) Seymour (amphibian-reptile transition) Jonkeria (colossal mixed diet) Thrinaxodon (small digger) Captorhinus (robust lizard). Marine and Aquatic: Helicoprion (circular saw shark) Diplocaulus (boomerang-headed amphibian) Mesosaurus (swimming reptile) Xenacanthus (eel-like shark) End of the Paleozoic Era The Mesozoic continues.