Lecture 4 Flashcards
(24 cards)
List the four classes of tetrapods
Amphibia
Reptilian
Aves
Mammalia
Examples and Characteristics of Amphibia
Pedicellate teeth
Cylindrical vertebral centra
Two auditory ossicles
Modern frogs and salamanders
Examples and Characteristics of Reptilian
Classified based on number of fenestrae (holes in skull) Anapsid Synapsid Diaspid Cotylosaur - stem reptile Modern snakes and lizards
Examples and Characteristics of Mammalia
Jaw articulation pattern: Occurs between temporal bone and mandible bone Live birth Endothermy (homeothermy) Respiratory Diaphragm Four chambered heart with completely divided ventricle Double occipital condyle Bony secondary palate Dentary - mandible consisting of a single bone Loss of interclavicle Hair/fur Posses mammary glands
Temnospondyls
Group of Devonian tetrapods that presumably gave rise to modern amphibians
Three orders of modern amphibians
Caudates (urodeles)
Anurans
Apodaca
Caudates
Possess tale - urodeles
Include modern salamanders
Anurans
Lack a tail
Modern frogs and toads
Apodaca
Lack limbs
Modern caecilians
Wormlike, externally segmented, burrowing, subterranean amphibians
What are the two groups of anapsids
Cotylosaurs (stem reptiles)
Chelonia (turtles…maybe)
Cotylosaur Characteristics
Stem reptile
Dermal armor
Skulls laterally flattened rather than dorsoventrally flattened (as in amphibians)
No additional skull openings behind orbits
Captorhinids
Temporalis muscles major jaw closing muscles
Diapsid characteristics
Two arches
Two lateral cheek openings behind each orbit
Each opening is bound by a bony arch (lost in many modern diapsids)
Distinguishing feature between two groups of dinosaurs
Pelvic girdle
(Ornithischians) - bird-hipped dinos
Saurischians - lizard hipped dinos
Three subgroups of modern lepidosaurs
Sphenodon
Snakes
Lizards
All true diapsids- two lateral cheek openings behind orbitals
Explain why dinosaurs form a paraphyletic group
Group includes ancestor of birds and dinosaurs but does not include birds
List reptilian characteristics found in Archaeopteryx
Bony tail (birds have replaced with bony tail and feathers)
Separate fingers with claws (birds have reduced digits w/out claws)
Teeth (birds lack teeth)
List the four theories on the origin of flight
- Thermal insulation
- Insect catching net
- Helped prey pursuit or escape from predation
- Helped early archosaurs roost at night
Earliest group of synapsids
Pelycosaurs
Characteristics shared by mammals and advanced therapsids
Secondary palate Pterygoid bones solidity to brain case Enlarged dentary bone DIfferentiation of teeth into incisors, canines, and cheek teeth Legs pulled in Ilium extended forward Elongated Sacrum Feet well-developed Jaw articulation pattern
Identify mammalian characteristics
Live birth Endothermy (homeothermy) Respiratory diaphragm Four-chambered heart with completely divided ventricle Neocortex Double occipital condyle Dentary (mandible consisting of a single bone) Bony secondary palate Hair/fur Mammary glands
Three groups of modern mammals
Placentals - live birth
Monotremes - egg- laying mammal, retain reptilian cloaca
marsupials - pouches mammals such as possum and kangaroo
Earliest group of mammals and their dentition
Morganucodonts- Heterodont dentition with triconodont molars
Adaptive radiation
Plants establish terestrialism, inverts followed, tetrapods began to get after them. Lungs developed. Feet got more feety. Ect
List and describe some of the requirements of terrestrialism million
CCERD Changes in REPRO Changes in ORGANS FOR SPECIAL SENSES Exertion of nitrogenous waste Resistance to gravity Desiccation
