20. Reptiles Flashcards
what are reptiles?
they are tetrapods that are defined by an amniotic egg which allows breeding on terrestrial land.
what are the three clades amniotes can be split into?
reptiles, birds and mammals
what are five derived characteristics of amniotes?
amniotic egg
has an extraembryonic membrane - fluid
shell
reduced water loss - allows amniotes to be free from breeding in damp places
no larval stage
what are three derived characters of respiration in aminiotes?
ability to use the rib cage
efficent way to get air in and out
lungs folded for increased surface area
what are four important derived features of reptiles skin?
covered by epidermal scales
prevants water loss
formed by keratin
used in sexual selecton, communication and competition
what do reptiles excrete?
uric acid in reptiles
turtles excrete urea
what is an ectotherm and what group is?
rely on the external envionrment to heat - reptiles
what is an endotherm and what group of orgnaism does?
geneterate body heat internally - birds
what is the circulatory system like in reptiles?
double circulation (like reptiles)
developement of septum in heart
when did early amniotes live and what was their lifestyle?
split from common ancestor 350 MYA. lived in warm, mois areas but more tolerable of dry conditions. were predatory
what are the two ground ancestral amniotes split into
reptiles and synapsids
what are three early derived characteristics of reptiles?
scales containing keratin
shells with eggs laid on land
ectothermic
what was the major group of reptiles and when did they live?
parareptiles, which lived about 310-320 MYA
what is a characteristic of a diapsid?
has two holes on the side of its head for muscle attachement
define a anapsid
no holes (eg turtles)
what is special about pterosaurs (from group archosaurs, within diapsids)
they are the first flapping amniotes with wings up to 11 metres in wingspan
what is three special points of dinosaurs? (from group archosaurs, within diapsids)
included bipedal theropods
agile and fast
signs of parental care
what are two important lineages of dinosaurs?
ornithischians (herbivours, triceroptops) and saurischians (birds, sauropods, theropods)
look at phylogeny tree!!
what are the two surviving linenages of lepidosaurs?
tuatara and squmata
image below is squmatas
