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Notes on video lecture:
Vertebrate Environments
Notes taken by Edward Tanguay on February 24, 2017 (go to class or lectures)
Choose from these words to fill the blanks below:
beaches, shoal, tidal, layers, carbonate, features, less, sinks, anoxic, reefs, marine, shallow, scraped, ripples, brackish, 200, 150, exquisite, continental, scavenge, plankton, sediments, inhabited, chert, photic, land, Cambrian, light, slopes, saltier, mollusks, fossils, shales, mud, flatter, sources, geology, pelagic
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what kinds of environments the earliest vertebrates                   
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paleontology is blending of
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biology
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to understand how and why certain                  evolved, we need to interpret the rocks that fossils are found in
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this tells us what kinds of environments the animals lived in
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depositional environments on          are more common
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depositional environments in the ocean are less common
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since life began in the oceans, we need to understand this habitat and its depositional environments
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most common place to find fossils of              organisms like fish, corals, crustaceans, or clams
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the continental shelf
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in the                waters off the coasts of continents
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               are high energy environments
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delicate fossils can be broken and eroded
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continental              and the deep ocean are hard for us to reach
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how to tell what the environment was like when the fossil animals were alive
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geologists interpret rocks in two ways
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what the rock is made of
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what kind of sedimentary structures were preserved when the rock was deposited
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there are also fossils in                    rocks
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made up of at least 50% calcium carbonate
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mostly limestone
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limestone is made up of the shells of marine animals such as                 
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key fossil localities
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rivers
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most energetic near their                in highlands
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most rivers transport and deposit sand and mud
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some with strong currents move gravel
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lens shaped sand or gravel channel deposits are an indicator of a fluvial environment
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as rivers travel over gradually                land, change to meandering rivers with shallower, wider channels
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able to transport          material
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rivers end up at an ocean, sea, or large lake
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empties into sea at a delta or an estuary
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here you find carbonate sediments
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water here is                 , i.e. not as salty as ocean water
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some animals and plants are adapted to live in this type of water
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heavily influenced by actions of the tidal current which produces sedimentary structures
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herringbone cross-stratification
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alternating parallel             
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this means the sediments were probably deposited in a            environment
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horizontal beds are called cross beds
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inclined layers are cross-strata
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sediment was being deposited fast in order to preserve the cross-stratification
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waves also affect cross-stratificaton
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wave base
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deeper during storms
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shallower during fair weather
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many fossil localities were deposited below storm wave base
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usually have             
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rocks with the most                are from the shallowest environment
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barrier islands
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spits
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small point of land running into the sea, or a long, narrow            extending from the shore into the sea
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lagoons
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areas of quiet, low-energy water
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fine sediments can be deposited here
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water evaporates and concentrates minerals
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can become                than ocean water
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forms evaporate
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calcite
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calcium carbonate
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gypsum
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anhydrite
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calcium sulfate
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halite
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sodium chloride
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usually what we mean when we say salt
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interbedded with       
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if we find these minerals, there is a good chance we are looking at what used to be a shallow lagoon
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good environments for preserving               
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because the water is still
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are still and salty
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not a lot of things can live in them
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becomes             , i.e. little oxygen
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this means if an animal falls into the lagoon and sinks to the bottom, there aren't many animals living their to                  the carcass
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small grain size tells us that the waters were very still
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good for preserving details
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here we find some of the most                    fossils every found have come from lagoon or lagoon-like environments
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Archaeopteryx
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deeper continental shelf environments
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Man on the Hill
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preserves 415 million year old vertebrate fossils
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accumulated in deep water on the continental shelf
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the environment was close enough to land for fine                    to be deposited
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but far enough offshore that most of the sedimentation was carbonate
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ripples became less common
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carbonate platforms
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where you find marine fossils
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the              zone
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where            penetrates
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a few centimeters to        meters deep, depending on the clarity of the water
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plankton
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float and form the basis of the marine food chain
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here we find           
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corals thrive in nutrient-rich water
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the steeper the slope, the less stable
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plate corals
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make the most use of the least light
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in deeper waters, chances of finding vertebrate fossils becomes relatively small
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turbidites
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deposits that can form in many environments
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occur in deep water
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Burgess Shale
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most famous                  fossil locality area in the world
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famous for the exceptional preservation of the soft parts of its fossils
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likely deposited by a turbidity current
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ocean floor
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here we don't find many vertebrates
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find mostly skeletons of                 
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these animals are               
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spend their lives floating in the water column
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fine-grained silica-rich microcrystalline or cryptocrystalline sedimentary rock that may contain small fossils
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most of the sea floor in earth's history has been melted and recycled into new crust, taking its fossils with it
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the old ocean crust still in today's ocean is about        million years old
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not that old compared to the oldest                        rocks
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over 4 billion years old
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when an oceanic plate means a continental plate, the oceanic plate           
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the oceanic crust is subducted beneath the continental crust
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most marine fossils come from continental shelf deposits
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when oceanic plates meat a continental plate, some contents get                off

Ideas and Concepts:

Our best fossils and the geological localities which produced them, via tonight's Vertebrate Origins class:

"The Archaeopteryx [German:Urvogel, "original bird"], [Greek:ἀρχαῖος (ancient) πτέρυξ (feather)], is a genus of bird-like dinosaurs that is transitional between non-avian feathered dinosaurs and modern birds. It lived in the Late Jurassic around 150 million years ago, in what is now southern Germany during a time when Europe was an archipelago of islands in a shallow warm tropical sea, much closer to the equator than it is now.

Over the years, twelve body fossil specimens of Archaeopteryx and a feather that may belong to it have been found. All of the fossils come from the limestone deposits, quarried for centuries, near Solnhofen, Germany. The initial discovery, a single feather, was unearthed in 1860 or 1861 and described in 1861 by Hermann von Meyer. It is currently located at the Humboldt Museum für Naturkunde in Berlin. The first skeleton, known as the London Specimen was unearthed in 1861 near Langenaltheim, Germany.

The reason we have these exquisite fossils of the Archaeopteryx is because they lived near lagoons, or areas of quiet, low-energy water. These are areas were fine sediments are deposited, where water evaporates and concentrates minerals, and thus becomes saltier than ocean water.

Since this leads to a waters with a high-salt concentration, it becomes anoxic, i.e. has little oxygen, and thus not many animals can live here. This means if an animal falls into the lagoon and sinks to the bottom, there aren't many animals living there to scavenge the carcass. Also, the small grain size tells us that the waters were very still and thus good for preserving details. This is why some of the most exquisite fossils every found, such as the Archaeopteryx, have come from lagoon or lagoon-like environments."
The Origin of Vertebrates
Vertebrate Environments
Diversity of Early Vertebrate Life