''Silvabestius'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...

dating to the

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...

. They were

grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to free range (roam around) and consume wild vegetations in order to feed conversion ratio, convert the otherwise indigestible (by human diges ...

animals about the size of a modern

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

. This animal is known from two

skulls The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

found close together which have come to be known as the "Madonna and Child"

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

.SILVABESTIUS
Accessed May 14, 2008. ''Silvabestius'' was 1 metre in length, with a skull about 25 cm long. It was a herbivore which browsed on soft plant matter such as leaves and stems and lived in an environment that largely consisted of tropical

rainforest Rainforests are forests characterized by a closed and continuous tree Canopy (biology), canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropi ...

. ''Silvabestius'' is in the family Diprotodontidae and is therefore related to the extinct giant marsupial ''

Diprotodon ''Diprotodon'' (Ancient Greek: "two protruding front teeth") is an extinct genus of marsupial from the Pleistocene of Australia containing one species, ''D. optatum''. The earliest finds date to 1.77 million to 780,000 years ago but most speci ...

'' as well as to living koalas and wombats. Two well preserved ''Silvabestius'' skulls were found close together, believed to be from a mother and child, in Riversleigh, Queensland, Australia. The juvenile is believed to have been in the mother's pouch when they died.

References

* Pat Vickers Rich, Thomas Hewitt Rich, Francesco Coffa, and Steven Morton (1990) ''Wildlife of Gondwana: Dinosaurs and Other Vertebrates from the Ancient Supercontinent'' (Life of the Past). Indiana University Press. * Long, J., Archer, M., Flannery, T., & Hand, S. (2002) ''Prehistoric mammals of Australia and New Guinea: One hundred million years of evolution''. University of New South Wales Press (pg. 97) * Diprotodontids Miocene marsupials Prehistoric mammals of Australia Riversleigh fauna Prehistoric marsupial genera {{Diprotodont-stub