Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
26 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
Lepidosauria groups |
Rhynchocephalia and Squamates |
2 |
|
|
SDC'S of Lepidosauria |
Tranverse cloaca slit, skin shedding, knee joint, and caudal automy |
|
|
|
Describe Lepidosauria evolution |
Appeared around 300 MYA, sphenodonts radiated then disappeared around 100 MYA |
|
|
|
Describe Rhynchocephalia |
Sphenodonts (tuataras), they are morphologically conserved and have spines on backs. |
|
|
|
SDC'S of Rhynchocephalia |
Primitive diapsid skull heterodont dentition, lack Intermitten organ, vomeronasal organ. |
|
|
|
General characteristics of Rhynchocephalia |
Lack internal ears, fertilization internal, parietal eyes, burrowers, nocturnal eyes, eggs slow to develop |
|
|
|
Two groups of Squamates. |
Scleroglossa (derived) jaw eaters Iguania (primitive) tounge eaters |
|
|
|
Two SDC'S for Squamates |
1) hemipenes that allow them to reproduce frequently from whatever side 2) kinetic skull allows them to apply equal pressure to food and more flexibility |
|
|
|
Describe Squamates evolution |
Arose in pensylvanian. Laurasia was the center of their evolution. Modern lizards appeared in late cretaceous. Megalina lived in Australia with humans. Trend in Squamate evolution is limb reduction. |
|
|
|
Describe snake evolution |
Either came from marine lizards (transitional fossil), burrowing lizards (based on morphology), or venomous lizards (shared toxins) |
|
|
|
Characteristics of snakes |
Right lung dominant, modified diapsid skull, tympanic membrane and eustachian tubes absent, pectoral girdle absent, pelvic girdle and hind limbs reduced or absent |
|
|
|
Describe territory in Squamates |
Inguanians (primitive) are territorial Scleroglossa (derived) are not territorial |
|
|
|
Describe ecology of Squamates |
Typically eat things smaller, biomass exceeds bird and carnivorous mammals, marine iguanas colonize oceans, marine elapids dive for a very long time |
|
|
|
Describe thermoregulation in Squamates |
Can active or passive. Cylindrical bodies loose heat and gain heat quickly. |
|
|
|
Describe osmoregulation in Squamates |
Loose a lot of water shedding, drink standing water, desert lizards use capillary action to bring up water to their mouth. |
|
|
|
6 locomotions of Squamates |
1) Lateral undulation - swing body side to side 2) Slide pushing - snake thrashing on smooth surface 3) Concertina - bracing and pushing/pulling 4) Side winding - moving at 60 angle minimize contact with ground 5) Rectolinear - catipilar 6) Gap bridging - moving from tree to tree |
|
|
|
Vision in Squamates |
Diurnal iguanians have color vision. True chameleons have separate eye functions, snakes are primitive to derived (with number of cones and rods) like they are |
|
|
|
Elapids venom |
Affects neuromuscular transmitters |
|
|
|
Scolecophidians |
Worm snakes, no distinct necks, short blunt tail, smooth scales, vestigial eyes |
|
|
|
Alethinophidians (true snakes) |
Head distinct from body, tapered tails, ventral scales enlarged, image forming eyes |
|
|
|
Elapidae |
Proteroglyphic fangs |
|
|
|
Viperidae |
Solenoglyphic fangs |
|
|
|
Leptotyphlopidae |
Teeth lower mandible |
|
|
|
Boidae |
Boid spurs in male |
|
|
|
Scolecophidians skull |
Skull is primitive short quadrate |
|
|
|
Alethinophidians |
Extra flex point in skull provides more flexibility. |
|
