LECTURE 6 Carboniferous Pd Mississippian Pennsylvanian 360 mya

LECTURE 6: Carboniferous Pd (Mississippian & Pennsylvanian) 360 mya- 286 mya and Permian Period 290 mya – 248 mya

Why is it Called the Carboniferous Period? • Continents were clustered at the equator

Why is it Called the Carboniferous Period? • Swampy tropical forests covered the continents – Seedless Tracheophytes: tall ferns, horsetails and lycophytes dominated

Why is it Called the Carboniferous Period? • Latin terms: Carbo (coal) and ferre (to bear) • The forests are called coal forests • Plants that lived in these forests 300 million years ago became coal mined for fuel today – Dead plant material accumulated and pressure left compressed carbon— coal—behind

What is Chicago’s Mazon Creek Area? • Before the Carboniferous Period, Chicago had been an underwater reef, but during this time it became a great forest • This site produces some of the world’s best fossils from the Carboniferous Period – Plants, centipedes and millipedes, scorpions and other arachnids, and even small amphibians • Some Arthropods were GIANTS – Tully Monster (Illinois State Fossil)

• 2 meters Long Millipede

Tully Monster Tullimonstrum gregarium Marine, Carnivore (blown ashore)

What Significant Events Occurred During the Carboniferous? • Radiation of Tetrapod Diversity • Amniotic Egg Appears – The shell and amniotic fluid prevent the developing embryo from drying out – FIRST REPTILE

Radiation of Terrestrial Tetrapods • Temnospondyls Amphibiamus – Fish-like bodies were replaced with large predators with long snouts, short sprawling limbs and flattened heads – Non-amniotic – Layed eggs in water • Anthracosaurs – Reptile- Like amphibians – non-amniote tetrapods and amniotes with holeless skulls – Descendents to Reptiles and Synapsids (mammal-like reptiles)

Reptile and Synapsid Diversity • Holes in their skull differ • Reptiles – One or more holes, but these holes are never located directly behind the eye sockets • Anapsids – No openings – Early Reptiles • Diapsids – 2 openings – only group living today: Lizards, snakes, turtles, and crocodiles, as well as dinosaurs and their living descendants: birds • Synapsids – Single opening just behind each eye socket – The only synapsid group living today are the Therapsid cynodonts (Mammals) • a palate that separates the nasal passage from the mouth. This palate allows cynodonts to breathe and chew at the same time—something you can do that other synapsids could not do

What was Hylonomus lyelli ? • First animal adapted to life fully on land (FIRST REPTILE) 320 mya – Anapsid • 20 cm (8 in. ) long, counting the tail • Lizard-like reptiles were insectivores • Females probably deposited amniotic eggs on land in moist, sheltered areas

What was Archaeothyris? • First Mammal- Like Reptile

What was Petrolacosaurus? • Oldest Diapsid Reptile – 2 holes

What Adaptations for Land are Seen in Early Reptiles? • Amniotic Egg – A yolk provides food for the developing embryo – Moisture and oxygen are absorbed through the porous shell – Eggs develop outside the mother's body (Oviparous) • Dry, Scaly Skin – The scales are thickenings of the outside layer of skin and are mostly made of keratin • Cold- Blooded: Ectothermic (like Amphibians) – They depend on the environmental temperature for the warmth that they need (low metabolism- until they are warm) • Defense Mechanisms – Bony shells, sharp teeth, camouflage and warning colors

What were the Significant Events During the Permian Period? • Supercontinent Pangaea • Three basic environments— arid, tropical, and temperate • Amniotes became common – Reptiles and synapsids (Therapsids- mammalian ancestors)—spread across the supercontinent • Mass Extinction #3

How does Climate Affect Plant Diversity? • Arid (Dry) – Zones near the equator quenched by rain in the summers, but drier the rest of the year • Most spore-bearing plants, such as ferns, need wet conditions for sperm to swim to the egg. They did better nearer the equator where there was seasonal moisture – Zones slightly further from the equator were arid desert year-round • Seed-bearing plants could survive in the driest zones because their sperm is transported inside a pollen grain • Tropical Everwet – Some zones near the equator were wet and green • Ferns (Seedless Tracheophytes), seed ferns, palm-like cycads, and cordaites (relatives of today’s conifers) • Cool Temperate – Some zones were closer to the poles and had a climate that was cool and had distinct seasons – To conserve resources when temperatures cool, some plants lose their leaves, growing new ones when temperatures warm up • As plants differed based on their climate, animals that inhabited each of these environments differed, too

Glossopteris (Leaves that have fallen) Walchi piniformis (Conifer with Seeds)

PERMIAN REPTILES • Diapsid reptile skull – Youngina romeri • Cyonosaurus longiceps – Synaspid

What was Tetraceratops insignis? • First Therapsid – Synapsid Reptile – Group that gave rise Mammals

Permian Reptiles

What Caused the 3 rd Mass Extinction? • Global warming – Scientists aren't exactly sure what triggered this mass extinction – Volcanic eruptions of this size would have released enough gases to trap heat in the atmosphere • Today, massive lava flows dating to the end of the Permian Period cover vast areas in Siberia. • Most devastating mass extinction in Earth’s history – It lasted from roughly 251 million to 250 million years ago – Over 90% of marine animals and 80% of land animals (ALMOST ALL LIFE)