Diprotodontia (MASSIVE ORDER) Flashcards
a. Taxonomic diversity b. Distinguishing features (esp. in relation to distal limbs and dentition) c. Adaptations with respect to diet d. Adaptations with respect to locomotion e. Reproductive features
Taxonomic Diversity
11 Families
88 Species
Phalangeridae
Cuscuses, BRUSHTAIL possums
Petauridae
Gliders and Trioks
Pseudocheridae
RINGTAIL possums
Phascolarctidae
Koala
Vombatidae
Wombats
Macropodidae
Kangaroos and Wallabies
Key diprotodont features
- most specialised and recently evolved
- syndactyly between 2 and 3
- greater development of salivary glands
- greater expansion of gut for fermentation
- diastema
- no lower canines
- lower incisors well developed
Key Vombatidae features
NO TAILS
- adaptations for burrowing
- rearward opening pouch
- herbivorous
- open rooted teeth (grow continuously)
- long GI tract (hindgut fermenters)
Key Phascolarctidae features
- 1 species
- NO TAIL
- adaptations for climbing
- rearward opening pouch
- folivorous for eucalyptus
- GI tract v long with extensive caecum
- FORCIPATE hand (1 and 2 opposable)
- opposable hallux with no claw
Key Phalangeridae and Pseudocheridae characteristics
- both arboreal
- prehensile tails
- short face
- same distal limb structure to koala
- simple stomach
- enlarged caecum HINDGUT
Key Petauridae features
- gliding membrane on lateral body wall between wrist and ankle
- gliding has evolved in 3 marsupial families
- omnivorous, focussing on nectar and insects
- can be seen to be exudativorous (feeding on exudes)
- exquisitely adapted 4th digit on forelimb to probe wood
Key about Macropodidae digestion
FOREGUT FERMENTERS
- stomach large and sacculated
Macropod Dentition
sequentially erupting molars
- teeth shed as they are worn
Describe embryonic dipause in Macropodidae
a female will mate while she has a young in the pouch and resulting conceptus is held in uterus in ‘suspended animation’ until first young has finished suckling
How?
Blastocyst doesn’t immediately implant into uterus after reproduction has created zygote, maintains a state of dormancy
- can wait until conditions are right
