Paleozoic ( mya) events
Late Paleozoic-key things ･ ･ Several key things happen beginning at the end of the Silurian through the Permian - - Assembly of Pangaea (also spelled Pangea) > > rearranges amounts of shallow marine habitats > > rearranges climate of the world > > organisms are becoming more diverse > > more families of organisms appearing - - Development of Chordates > > probably in repsonse to increasing competition > > includes many common animals - - Development of land plants > >
Pangaea ･ ･ assembled by the early Permian ･ ･ as it comes together - - shallow epicontinental seas diminish in size > > periodic- i.e., still fluctuating but getting smaller - - Mountains are sources of sediment to the east and west in US
Devonian world- tectonic & paleogeographic setting
Devonian Paleogeography of N. America
Carboniferous (Pennsylvanian) world- tectonic and paleogeographic setting
Permian world- tectonic & paleogeographic setting
Schematic Cyclothem
Coal forests in Pennsylvanian and Mississippian evidence suggests they did not stray too far from water sources - - few plants in upland areas Plant species like Lepidodendron (a family of plants known as a Lycopsids) - - got really huge in the late Carboniferous Sphenopsids (spine-like rushes and horsetail plants) - - smaller than Lycopsids Both reproduce by means of spores as opposed to seeds
Ferns and tree ferns ･ also around beginning in late Devonian -haven't changed much in 370 million years ･ wide variety of sizes -some were small -some were as big as the biggest trees today
Seed bearing plants "seed ferns" were the first plants to produce true seeds - - unlike real ferns that produce spores for reproduction occurs in late Pennsylvanian Offers a resistant package that can be transported long distances before germinating
The “trunk” of a seed fern
Reconstruction of ostracoderm Pteraspis
A Placoderm fish about to munch on an unsuspecting lobe-finned fish
Osteichthyans "bony fishes" these show up in Devonian as well eventually giving rise to Tetrapods - - organisms that will eventually colonize the land
Colonizing land - animal kingdom Arthropods were first complex animals to colonize the land - - bugs! Amphibians were the first vertebrates to move onto land - - still tied to the water for reproduction though
Evolutionary links between lobe fins and tetrapods
Chondrichthyes fossil a fossil skate - - related to sharks - - and stingrays
Coelocanth fish lobe finned fishes are classified as Sarcopterygians and Crossopterygians
During the Carboniferous and Permian insects like dragonflies got very large Permian dragonfly had a wingspan of 1.5 meters!
Permian Tetrapod amphibian Cacops
Permian Reptile- Dimetrodon
a late Permian tetrapod amphibian
4 big extinction events during the Paleozoic Ordovician Silurian Devonian Permian