Koala around and its head has doubled in size. The eyes begin to open and fine fur grows on the forehead, nape, shoulders, and arms. At 26 weeks, the fully furred animal resembles an adult, and begins to poke its head out of the pouch. As the young koala approaches six months, the mother begins to prepare it for its eucalyptus diet by predigesting the leaves, producing a faecal pap that the joey eats from her cloacum. The pap is quite different in composition from regular faeces, resembling instead the contents of the caecum, which has a high concentration of bacteria.
Koala Because "Phascolarctos" was published first, according to the International Code of Zoological Nomenclature, it has priority as the official name of the genus. French naturalist Anselme Gaëtan Desmarest proposed the name "Phascolartos fuscus" in 1820, suggesting that the brown-coloured versions were a different species than the grey ones. Other names suggested by European authors included "Marodactylus cinereus" by Goldfuss in 1820, "P. flindersii" by René Primevère Lesson in 1827, and "P. koala" by John Edward Gray in 1827. The koala is classified with wombats (family Vombatidae) and several extinct families (including marsupial tapirs, marsupial lions and giant wombats) in the