Aussie Reptiles (lecture 4) Flashcards
taxonomics
“who is who”
-reptiles second most diverse after birds
4 orders of reptiles
- crocodiles
- turtles
- squamates (snakes and lizards)
- tuataras
squamates
- shows the greatest diversity among reptile species
- lizard diversity is in climate in Australia
- major representation of Australian fauna
phylogenetics def:
- is the study of evolutionary relatedness among groups of organisms
- diversification and where you end up with like minded species
phylogenetics
-a tree
- the further you go along the x axis show the relatedness
- y axis this that are closer together have similar evolutionary time
ancestral trait
-share traits with common ancestor
derived trait
-singular present trait that differentiate species
monophyletic
- single origin
- all mammals are
polyph
- multiple ancestral origin leading to present day form
- reptiles
phylogeny
- used physical traits to determine relationship between species
- changes over time
- as the system of relationship has evolved so has the phylogeny
- help understand the major evolutionary trajectory
crocodiles
- 2 species of crocodiles
- salt and freshwater
- haven’t change very much
- independent of dinosaurs
- heavily armoured body, long jaws, streamlined body, long tail
- aquatic predators
- pantropical distribution except in Africa
- most crocodiles have returned to the aquatic environment and have become smaller over the yrs.
crocodilus johnstoni(freshwater)
- live in the inland rivers and coast of queensland
- very shy
- inquisitive animals
crocodylus porosus (saltwater)
- extensively harvested in the 60s and 70s
- protected through legislation
- moved further and further inland to freshwater waterholes
- more than 5m long
- sit and wait predators
- people taken in the northern territory
- over 1k kg
- stash food in underground meat larva in water until hungry
- restricted to estuarine
turtles
- Australia has freshwater turtles
- have aquatic webbing for propulsion
- 24 species of longneck turtle (chelida)
- prized food in Northern Australia
family carettochelydidae
- pitted shell turtle
- endemic to certain rivers in the Northern territory and New Guinea
- quite aquatic with nostrils
family chelida
- side-necked turtles
- produce stink secretion
- Gondwanan
- 7 genera
- 24+ species
family cheloniidae
-hard shell turtle
ex.
logggerhead turtle
green turtle
hawksbill turtle
pacific ridley
flatback turtle
family dermochelyidae
- leather back turtle
- 1 genus/species
- in much cooler water
- exchange muscle for increase in body heat
- range distribution is a big larger than other turtles
lizards
- over 600 species, more than any other country in the world
- endemic radiation
- 4 species
1. geckos
2. skinks
3. dragons
4. goannas
Geckos
- things that run up the wall and make funny noises
- major group (20 genera, over 150 species)
- almost exclusively nocturnal
- 15% of total reptile diversity
- exploits dropping tail (tailatonomy) through fracture planes in vertebrates
- store fat and water in tails
- squeak for communication (alarm calls and signaling territory)
- have sticky feet-heads of feet enables adhesion
- 4 major families
Skinks
- most diverse group
- make up 25-30% of lizard diversity
- most common genus and family
- 365 species in Australia, 35 genera
- Vi
- live in the substrate they acquire
- major role on soil turnover and leaflet breakdown
- feed in small insects
- vary in color
- similar mythology
- blue-tongue is a defense mechanism to confuse predators
- high diversity or variation of skinks in Australian desert
- various level of limb reduction to get through the sand
- front legs then hinf
Dragons
- recent invasion
- common in Africa and southeast asia
- enter Australia 30 mya
- not specio
- 65 specie
- fast moving and sun loving
- incredibly complex social display
- complex in communication
Goannas
-70 or 80 species
-3rd major group
corruption of the ord iguana
-recent to Australia (30 mya)
-1 genius/27 species
-most energetic reptiles
-related to the Komodo dragon
-high metabolic rate
-very active predators
-arboreal
-very diverse
-located in forest and on rock s
-very prolific predators, very active
-all related to giant lizard
-most diverse predator
Goanas and Snakes
forked tongue-incredible sensory organ ritualize male combat -establish dominance -dominant creature pretends to scratch the back of the inferior creature -classic ex. of convergence evolution
convergence evolution
-animals evolve with similar traits but come from different ancestors
snakes
- nonvenomous second most diverse
- single common ancestor
- extremely divers
- many family of snale
- python diversity occurs with the climate
- very large
- focus on vertebrate prey
- use infrared to capture prey
Elapidae
- very poisonous
- 80 species, 20 genera
- recent radiation
- radiates in all habitats in Australia
- rich in desert
- extremely diverse group in Australia
- prey on invertebrates
- front-fanged venomous snakes
