{{Short description|Extinct species of marsupial}} {{speciesbox | fossil_range = Middle Miocene {{fossilrange|14.2|12.9}} | taxon = Maximucinus muirheadae | authority = Wroe, 2001 }}
'''''Maximucinus''''' is an extinct genus of thylacinid that lived during the Middle Miocene in what is now Queensland, Australia. It is known only a second upper molar found at the Riversleigh World Heritage Area. It was the largest thylacinid of its time, attaining a body size of 18 kg (40 lbs). The genus is monotypic, containing only one species, '''''Maximucinus muirheadae'''''.
==History and naming== ''Maximucinus'' was described as a new genus and species of thylacinid in 2001 by Stephen Wroe. The holotype and only known specimen, catalogued as '''QM F30331''', is an isolated second upper molar. It was collected from the Ringtail site at the Riversleigh World Heritage Area, north-western Queensland.<ref name="Wroe2001">{{cite journal |last1=Wroe |first1=S. |author-link1=S. W. Wroe |title=Maximucinus muirheadae, gen. et sp. nov. (Thylacinidae: Marsupialia), from the Miocene of Riversleigh, north-western Queensland, with estimates of body weights for fossil thylacinids |journal=Australian Journal of Zoology |date=2001 |volume=49 |issue=6 |pages=603–314 |doi=10.1071/ZO01044}}</ref> The site has been radiometrically dated to the Middle Miocene, ~14.2-12.9 Ma.<ref name=Woodhead14>{{Cite journal|last1=Woodhead|first1=J.|last2=Hand|first2=S.J.|last3=Archer|first3=M.|last4=Graham|first4=I.|last5=Sniderman |first5=K.| last6=Arena| first6=D.A.|last7=Black|first7=K.H.|last8=Godthelp|first8=H.|last9=Creaser|first9=P.|last10=Price|first10=E.|year=2014|title=Developing a radiometrically-dated chronologic sequence for Neogene biotic change in Australia, from the Riversleigh World Heritage Area of Queensland.|journal=Gondwana Research|volume=29|issue=1|pages=153-167|doi=10.1016/j.gr.2014.10.004|hdl=1959.4/unsworks_36975|hdl-access=free}}</ref>
The genus name combines the Latin word ''maximus'', large, with ''kynos'', the Ancient Greek word for dog. The species name was chosen to honour fellow researcher Jeanette Muirhead, for their contributions towards the study of fossil thylacinids.<ref name="Wroe2001"/>
==Description== ''Maximucinus'' is known only from a single specimen, an upper molar. Although the fossil material is scant, it has enough traits to differ it from all thylacinids. Stylar cusps B and D are well-developed. Furthermore, the aforementioned stylar cusps are compressed to the sides of the molar. The front most cingulum (a small shelf-like structure situated at the base of a tooth's crown) continues into the preparacrista. Both the protoconule and metaconule cusps are extremely small.<ref name="Wroe2001"/>
Wroe (2001) estimated its weight to be 18 kg (40 lbs), making it the largest thylacinid discovered from the middle Miocene.<ref name="Wroe2001"/>
==Paleobiology== Fossils of ''Maximucinus'' are known only from a single site at Riversleigh, which dates to the Middle Miocene.<ref name="Wroe2001"/> The climate during the Middle Miocene would have been warm and permanently wet. Open rainforests would have covered the landscape at the time.<ref name=Woodhead14/><ref name=T09>{{Cite journal|last1=Travouillon|first1=K.J.|last2=Legendre|first2=S.|last3=Archer|first3=M.|last4=Hand|first4=S.J.|year=2009|title=Palaeoecological analyses of Riversleigh's Oligo-Miocene sites: implications for Oligo-Miocene climate change in Australia.|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=276|issue=1-4|pages=24-37|doi=10.1016/j.palaeo.2009.02.025}}</ref> Coexisting alongside ''Maximucinus'' would have been the thylacinids ''Muribacinus'' and ''Nimbacinus'', and the thylacoleonids ''Wakaleo oldfieldi'', ''W. vanderleueri'' and ''Lekaneleo myersi''. The two families of carnivorous marsupials were likely able to coexist with one another due to differences in both body size and vertical habitat segregation.<ref name="Gillespie2023">{{cite journal |last1=Gillespie |first1=A. K. |title=Two new marsupial lion taxa (Marsupialia, Thylacoleonidae) from the early and Middle Miocene of Australia |journal=Alcheringa: An Australasian Journal of Palaeontology |date=2023 |volume=47 |issue=4 |pages=506–521 |doi=10.1080/03115518.2022.2152096|bibcode=2023Alch...47..506G |s2cid=256157821 }}</ref>
The molar of ''Maximucinus'' shows some specializations towards hypercarnivory (i.e. minute protoconule and metaconule cusps), although it was clearly less specialised than that of later thylacinids as it still retains well-developed stylar cusps.<ref name="Rovinsky2019">{{Cite journal |last=Rovinsky |first=Douglass S. |last2=Evans |first2=Alistair R. |last3=Adams |first3=Justin W. |date=2019-09-02 |title=The pre-Pleistocene fossil thylacinids (Dasyuromorphia: Thylacinidae) and the evolutionary context of the modern thylacine |url=https://peerj.com/articles/7457 |journal=PeerJ |language=en |volume=7 |article-number=e7457 |doi=10.7717/peerj.7457 |issn=2167-8359|doi-access=free |pmc=6727838 }}</ref>
==References == {{Reflist}}
{{Agreodontia}} {{Taxonbar|from=Q6795826}}
Category:Prehistoric thylacines Category:Prehistoric mammals of Australia Category:Oligocene marsupials Category:Tortonian genus extinctions Category:Miocene marsupials Category:Riversleigh fauna Category:Rupelian genus first appearances Category:Prehistoric marsupial genera