Australia: The Land Where Time Began

A biography of the Australian continent 

Riversleigh Marsupial Lions - Thylacoleonids

Prior to the discovery of the Riversleigh deposits the only well-known marsupial lion known was from the Pleistocene, Thylacoleo carnifex, about the size of a modern leopard and distantly related to wombats. After some discussion about their diet, is has been agreed that they ate meat and probably bones. A study compared them to carnivores from around the world and the conclusion was that it was the most highly specialised meat-eater known to have evolved in the world, based on its huge, sectorial shearing premolar.

Among the species known from non-Riversleigh sites are Preisileo pitikantensis, a cat-sized species from the Late Oligocene, dog sizes species of Wakaleo from the Early Miocene, W. oldfieldi, and from the Middle Miocene, W. vanderleuri, and from the Late Miocene, W. alcootaensis. Some small-dog sized species of Thylacoleo are known from the Late Miocene, T. hilli, a leopard-sized T. crassidentatus from the Pliocene. A complete skull of W. vanderleuri has been found at the Middle Miocene deposits at Bullock Creek in the Northern Territory.

The first record of marsupial lions from Riversleigh was a maxilla of a Wakaleo sp., very similar in size to W. oldfieldi from Kutjamarpu Local Fauna in central Australia, that was found in the back of the mouth of a crocodile.  A 20 million year old skull that was discovered at Riversleigh appears to be intermediate between the 2 main lineages of marsupial lion, the Wakaleo and the Thylacoleo. Another find in the Upper Site was a complete skull of a tiny, about the size of a house cat, very primitive marsupial lion. It appears to be most closely related to Priscilio pitikantensis the oldest known marsupial lion from the Late Oligocene in the Tirari Desert in South Australia. The marsupial lion fauna at Riversleigh demonstrated that this particular niche was much wider than previously thought. It seems the evolution of feeding guilds, as also occurred among the bandicoots at Riversleigh, allowed a great diversification in the Riversleigh rainforest. The skull also demonstrates that a primitive form can survive amongst the more advanced forms of the group that arose from the ancient relatives of the primitive type. The same applies to the platypus. This Preisileo-like animal finally went extinct at some point during the existence of the Riversleigh rainforest.

Sources & Further reading

  1. Michael Archer, Suzanne J. Hand & Henk Godthelp, Australia's Lost World: Riversleigh, world heritage Site, Reed New Holland
Author: M. H. Monroe
Email:  admin@austhrutime.com
Last Updated 25/02/2011

 

Fossil Sites
Riversleigh Animals
    Lungfish
    Arthropods
    Bandicoots
    Bats
    Birds
    Crocodiles
    Dasyurids
    Diprotodontoids
    Ektopodontids
    Miscellaneous
    Feathertail Possums
    Frogs
    Kangaroos
    Koalas
    Lizards
    Marsupial Lions
    Monotremes
    Notoryctids
    Petaurids
    Phalangerids
    Pygmy-Possums
    Ringtail Possums
    Rodents
    Snakes
    Thingodonta
    Thylacinids
    Turtles
    Wombats
    Wynyardiids
    Yingabalanarids
Home
Journey Back Through Time
Geology
Biology
     Fauna
     Flora
Climate
Hydrology
Environment
Experience Australia
Aboriginal Australia
National Parks
Photo Galleries
Site Map
                                                                                           Author: M.H.Monroe  Email: admin@austhrutime.com     Sources & Further reading