''Maximucinus muirheadae'' is the largest known

thylacinid Thylacinidae is an extinct family of carnivorous, superficially dog-like marsupials from the order Dasyuromorphia. The only species to survive into modern times was the thylacine (''Thylacinus cynocephalus''), which became extinct in 1936. ...

species that lived in

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

, Australia from the late

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but ...

to the middle

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ...

. The species was a quadrupedal marsupial predator, that in appearance looked similar to a dog with a long snout. Its molar teeth were specialized for carnivory; the cups and crest were reduced or elongated to give the molars a cutting blade. It is estimated to have weighed about 18 kilograms. The holotype and only specimen is a second upper molar found in Riversleigh. The species is named after Jeanette Muirhead because of her work on

Taxonomy

The description was published in 2001 as a new species and genus, recognising greater diversity within the thylacinid family. The author, palaeontologist Stephen W. Wroe, was one of several researchers who discovered over ten new fossil species of thylacinids, mostly from new material extracted from sites at the

Riversleigh World Heritage Area Riversleigh World Heritage Area is Australia's most famous fossil location, recognised for the series of well preserved fossils deposited from the Late Oligocene to more recent geological periods. The fossiliferous limestone system is located ne ...

. Wroe distinguished the name of the new species by honouring fellow researcher

Jeanette Muirhead Jeanette, Jeannette or Jeanetta may refer to: * Jeanette (given name), a given name (including a list of people and fictional characters with the name) Places * Jeannette, Ontario, Canada * Jeannette Island, Russia * Jeannette, Pennsylvania, U.S ...

, whose own works had described new genera and species of the family in the preceding decade. The genus name combines the Latin ''maximus'', large, with ''kynos'', the Ancient Greek word for dog.

Description

Known only from a single specimen, an upper right M2 molar, Wroe estimated ''M. muirheadae'''s weight at 18 kilograms, the largest thylacinid discovered from the middle Miocene. The author used evidence of diversity and size range that emerged from research at Riversleigh, and other material from sites such as Alcoota, to produce new statistical analysis, calculated with

regression function In statistical modeling, regression analysis is a set of statistical processes for estimating the relationships between a dependent variable (often called the 'outcome' or 'response' variable, or a 'label' in machine learning parlance) and one o ...

s, that showed multiple evolutionary lineages within the family.

References

External links

Natural Worlds
Prehistoric thylacines Prehistoric mammals of Australia Oligocene marsupials Tortonian genus extinctions Miocene marsupials Riversleigh fauna Rupelian genus first appearances Prehistoric marsupial genera {{paleo-marsupial-stub