Reptiles (crocodylia and dinosaurs) Flashcards
What is Crocodylia, charecteristics for different species?
Not only crocodiles aparently.
Gharials
- Long narrow snout whit a bump at the end for males.
Alligator
- Broud snout, 4th tooth in the lower jaw can´t be seen when the mouth is closed.
Crocodiles
- Broud snout, 4th tooth in the lower jaw can be seen when the mouth is closed.
Crocodylia common characteristics?
Lizard like body form, with limbs are shorter and held out to the side of the body.
Minimum exposure to water. Only some of the head and breathing ways are visible.
Palatal valve is a piece of the throat which can open and close, which make the crocodylia able to have open mouth under water, whitout water running into the body.
Strong bite
Teeth are replaced up to 50 times during their lives. Every teeth have the same shap.
Characteristics by crocodylia heart, resperation, temperature and reproduction.
Heart is fourchambered like human´s, with a valve between the ventricles that allows some of the blood to miss out the lungs furing diving.
Resperation work like with birds, one way in and not the same way out. Unidirectional flow of air through the lungs.
Tempeture regulation, cool down by opening their mouth, while the body gets warm.
Reproduction is internal and sex of the young is dependent on the temperature.
Crocodylia senses?
Eyes have a transparent eyelid that moves sideways. The eyeballs can be retracted to avoid injury. Poor eye side underwater, good over, red eyeshine.
Hearing is good (best of reptiles), from small flaps behind the eyes. The flaps can be closed underwater.
Sensory pits are on the scales around the mouth, which are used to detect movement in the water.
Pterosaurs (first flying what?)
First flying Vertebrate, They are not dinosaurs! Probably not flying that well, but walk quite well.
Endothermic, with fluffy pycnofibres covering the body and wings. Which looked like hairs.
They breath unidirectional using air sacs
Have hollow bones
Used for flying, but also for walking
What changed from the early pterosaurs to the late.
The early one had teeth and longtails.
Ate insects or fish
In the end, most of them didn´t have tails, some had teeth, some didn´t and some had filtering hairs.
The later ones were bigger.
Specialized in eating a lot of different things, for the different species.
Pterosaurs sexual dimorphism, reproduction and discussion.
Many species had special head crests for sexual attraction.
Needed to put their egs in muddy (soft) ground. “Could be one of the reason why birds beat them in the end, becuase if you lay your eggs next to rivers their can be floaded away.”
Discussion about the young could fly when they hacthed, because their wing bones had not ossified (completly harden) and their mussels were not fully attached.
Other argue that young could fly, with cartilage and no strong muscles.
Dinosauria, what does the clade include
Dinosaurs and birds.
What is the difference about avian and non-avian
Avian dinosaurs = birds, only extant members of the dinosaur group.
Non avian dinosaurs = extinct members of the group.
What is the difference about Saurischia and Ornithischia. Discussion
Its all about them hips.
This changed the way we thing about the three major clades. Now we say, Sauropods are alone and Theropods and ornithischians are together.
Sauropods, characteristics?
Looooong neck, have fours legs, eats herbs, Dominant herbivore. ?saurischian hips?
Replacing their teeth 1x-2x each month. Difference in diet is reflected in their teeth.
The biggest animal that ever walks on the earth.
They grow really fast, which is a defence mechanism. Adult around 20 years. Die before our age.
Airsacks filtrate into the bones. Their bones whach light, for being able to fit air. The vertebrea consist of around 60% air.
Their neck wasn´t that flexible.
Social animalns
Brachiosaurus Diplodocus and Brontosaurus
In the sauropods family.
Long tails for balance and defense.
Spikes and flaps for display, maybe sexual dimophisim.
They have small, light skulls, with week leaf picking teeth. They didn´t use them for grinding, because they eat stomachs like hens.
Ornithischia
Mostly herbivorous, few were omnivores.
Bird-hipped - saurischian pelvis.
Predentary bone on the lower jaw, which was used to cut vegetation. Their teeth were usually leaf-shaped for cutting plant material, with grinding teeth too.
They lived in herbs like “gnu”.
Prey to the theropods (predotors). Therefore they had defensive structures.
