Day 21 Reptiles and Birds
About 350 million years ago vertebrates invaded land
-The first land dwelling vertebrates evolved from bony fish that crawled on land with two walking fins like the mud skippers
-Their swim bladders would evolve to become lungs
-The successful land vertebrates used four legs to walk around. Because of this ALL land vertebrates are called...
Tetrapods (Four Footed)
-Even snakes and whales are tetrapods because their ancestors had 4 legs.
-Tetrapods evolved from fish that had lungs. Living on land meant that you had to be able to take oxygen directly from the air so think of a tetrapod as all vertebrates that have lungs.
-Tetrapods are...
-Amphibians
-Reptiles
-Birds
-Mammals
Class Amphibia
Amphibians (Common Name)
-The first land vertebrates were the amphibians
-They have two lives, one in water and one on land.
-Amphibians have aquatic eggs. So their eggs need to be kept underwater. A juvenile amphibian has gills and lives fully aquatic. To becomes an adult it goes through metamorphosis and grows lungs so it can live on land. Because of this life cycle, amphibians cannot live far from water.
-Amphibians evolved from freshwater fish.
-Because Amphibians evolved from freshwater fish there is no such thing as a marine amphibian. There has never been a marine amphibian. Amphibians cannot handle salt water.
-Because there are no marine amphibians we do not study them in marine biology
Kate Terbush
Class Reptilia
Reptiles (common Name)
-Reptiles solved the land egg problem. Unlike amphibians, reptiles can spend their whole life away from water
-Reptiles have an amniotic land egg that will not dry out. So it can be lied on land
-This is how dinosaurs took over the world
-Reptiles evolved on land but some of them moved into the ocean. These are called marine reptiles. Some examples of marine reptiles are...
-Sea turtles
-Sea Snakes, Sea kraits (a type of sea snake)
-Marine Iguana (the only extant marine lizard)
-Saltwater crocodile (although the saltwater crocodile is not truly marine since it mostly lives in brackish waters like estuaries.
-Because of the land egg, marine reptiles still have to lay their eggs on land. Reptile eggs will drown under water.
-For example sea turtles have to crawl onto land every year to lay their eggs. When their eggs hatch, the baby sea turtles have to hurry into the water as fast as they can.
Watch this TedEd video on sea turtle survival. Create a box or separate section in your sketchbook and title it "Sea Turtle Survival". Take notes, write down anything you might find interesting and include a picture.
Watch this Jonathan Bird video on sea turtle mating and egg laying. Create a box or separate section in your sketchbook and title it "Sea Turtle Reproduction". Take notes, write down anything you might find interesting and include a picture. Make sure you know how to identify a male vs female sea turtle.
Sea snakes are one of the most venomous animals on the planet. Sea snakes are related to cobras.
-Sea snakes give live birth in the water and never have to come on land.
-Sea Kraits are a type of sea snake that has to come on land to lay eggs.
-Even though sea snakes are highly venomous, they are not dangerous to humans. Sea snakes cannot open their moth wide enough to bite a human. If they were able to somehow bite a person, the person would die from the strong venom.
Watch this Jonathan Bird video on sea snakes. Create a box or separate section in your sketchbook and title it "Sea Snakes". Take notes, write down anything you might find interesting and include a picture.
This is an optional video with facts of sea snakes
The marine iguana is the only marine lizard. They are only found on the Galapagos islands.
They can hold their breath for 10 minutes or longer. They dive to eat algae off of underwater rocks.
Watch this Animalogic video on marine iguanas. Create a box or separate section in your sketchbook and title it "Marine Iguanas". Take notes, write down anything you might find interesting and include a picture.
Optional video on ichthysaurs. Ichthysours are ancient marine reptiles.
Class Aves
Birds (Common name)
-Birds have a hard shelled egg
-Are endothermic (create their own heat)
-Have feathers (Not all can fly)
Sea Birds
(A sea bird is any bird that spends a significant amount of its time at sea and feeds on marine organisms)
Birds have some advantages over reptiles
-Ability to fly
-Bodies are covered in water proof feathers that conserve body heat
-Water proofing is provided by an oil that is secreted from a gland above the base of the tail.
-Birds rub the oil all over their feathers as the preen
-Bodies are light because of hollow bones
-Eggs have hard shells that are more resistant to water loss
Penguins
-Penguins are the best adapted sea bird for life at sea
-They are Flightless
-Most of the 18 species of penguin live primarily in Antarctica
-The Galapagos Penguin lives in Galapagos
-The Humboldt Penguin lives in Chile
Spend a minute or longer enjoying the Live Feed of the Penguins at the Aquarium (Above water) (Underwater)
Watch this PBS video on penguin evolution. Create a box or separate section in your sketchbook and title it "Penguin Evolution". Take notes, write down anything you might find interesting and include a picture.
Tubenoses
-These are sea birds like the Albatross, Shearwaters (Puffin) and Petrels
-They have a tubed shaped bill and have salt glands that empty into the nostrils.
Kate Terbush
Other common sea birds are...
Sea Gulls and Pelicans
Watch and enjoy this Deep Look video on Pelicans
Watch and enjoy this horrifying video of pelicans hunting baby birds