Lecture 18 Flashcards
vertebrate
Know what graptolites are and when they were common
are colonial animals that are composed of tiny organisms called zooids. lived together in a structure made of chitin called a rhabdosome which could float or attach to substrate. were more common during Ordovician and Silurian period
Know the basics of the chordate body plan
ppt
How is this body plan expressed in the juveniles and adults of tunicates?
Juvenile tunicates look like small fish with a notochord and a nerve cord, but adults lose these features and become stationary, filter-feeding creatures with a sac-like body.
What is an “agnathan?” Which feature of vertebrates is missing in some
craniates? Know that lampreys, hagfish, and conodonts are jawless fish
a. agnathan refers to a group of jawless fishes
b. craniates some of them are missions jaws
c. lampreys, hagfish, and conodonts are jawless fish
What are ostracoderms, and when did they live?
extinct group of jawless fish that had a bony external armor protecting their heads. lived primarily during Paleozoic era
Who are the gnathostomes?
group of vertebrated that had true jaws.
-fish, amphibians, reptiles, birds, and mammals
Know the basic features of the jawed fish groups: placoderms, chondricthyes,
osteichthyes, as well as the two osteichthyan groups sarcopterygia and
actinopterygia
ppt
Which fish group gave rise to tetrapods?
lobe finned fish or sarcopterygii had fins, lungs and gills, and stronger skeletal structure
What are the basic design differences between tetrapods and fish? Which of
these features does Tiktaalik have
fish had fins, gills, flexible spine, and sensory systems while tetrapods have limbs, lungs, robust skeletal structure, and olfactory system.
tiktaalik is called a fishpod that had fins that resemble limbs, had gills and lungs, and had sensory system that was helpful for both terrestial and aquatic.
How are amphibians (basal tetrapods) tied to life in the water?
Amphibians are closely tied to water because they lay their eggs in water, their larvae like tadpoles live in water, and their skin needs to stay moist for breathing and to prevent drying out.
Who are the amniotes? What are the three major amniote groups based on
skull design, and which of the familiar modern groups of amniotes belong to
each one? Which one probably has no living members?
a. amniotes are a group of four limbed animals with backbone that evolved in amniotic egg.
b. anapsid(early reptiles) , diapsid (all birds and crocodiles, and all modern reptiles except turtles) , and synapsid (all mammals)
c. anapsid has no living members
What amniote features allowed them to take over the dry land? Which of
these are similar to what we saw in seed plants, and which are different?
Amniote features that allowed them to thrive on dry land include the development of the amniotic egg, which protects the embryo from drying out, and tough, scaly skin that prevents water loss. Similar to seed plants, amniotes use a protective structure (amniotic egg) akin to a seed’s protective coat; however, unlike plants, amniotes are mobile and regulate their internal temperature, which plants cannot do.
What are the three synapsid groups we talked about? What important
mammal-like features developed in the non-mammal synapsids?
-pelycosaurus, therapsid, and mammals
-Non-mammal synapsids developed several important mammal-like features, including differentiated teeth (like incisors, canines, and molars), a more advanced jaw hinge mechanism, and a larger brain relative to body size.
What are the two diapsid groups we talked about, and who belongs to each?
archosaurus: crocodiles, dinosaurs, and birds
lepidosaurus:lizards, snakes, and sphenodontian
