Neohelos

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Neohelos
Temporal range: Miocene, 23–12  Ma
Neohelos skull.jpg
Skull of Neohelos stirtoni at the Melbourne Museum
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Diprotodontia
Family: Diprotodontidae
Subfamily: Zygomaturinae
Genus: Neohelos
Stirton, 1967
Type species
Neohelos tirarensis
Stirton, 1967
Species

N. tirarensisStirton, 1967
N. stirtoniMurray et al., 2000 [1]
N. solus Black et al., 2013
N. davidrideiBlack et al., 2013

Contents

Neohelos is an extinct diprotodontid marsupial, that lived from the early to middle-Miocene. There are four species assigned to this genus, Neohelos tirarensis, the type species, N. stirtoni, N. solus and N. davidridei. N. davidridei is the most derived species of the genus, and its premolar morphology shows that it is structurally and ancestor of the genus Kolopsis . All four species are from the Bullock Creek in the Northern Territory and Riversleigh of Australia.

Description

Neohelos is known from many specimens, assigned to all the species. N. tirarensis includes a partial skull, premaxillas, maxillas, teeth, and dentarys; N. solus is known from a maxilla and dentary; N. davidridei includes teeth and a maxilla fragment; and N. stirtoni is known from a mostly complete skull, a maxilla and a dentary. [2]

Distinguishing characteristics

A revision of Neohelos found a set of features in all the species that are absent in all other diprotodontoids. They are listed below: [2]

Classification

N. solus holotype Neohelos solus holotype.jpeg
N. solus holotype

Neohelos includes many species. Among them, N. davidridei is the most derived. N. davidridei shows many features that are also found in Kolopsis , and is thought to be the ancestor of it and its species. Together, Neohelos and Kolopsis make up Zygomaturinae along with Zygomaturus and other genera. [2]

Paleoecology

Neohelos lived in the early to Middle Miocene of Queensland, Australia. It is one of a few diprotodont genera that existed in all three of Bullock Creek in the Northern Territory, Riversleigh in Queensland, and the Wipajiri Formation of South Australia. [2]

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References

  1. Murray, P.; Megirian, D.; Rich, T.; Plane, M.; Vickers-Rich, Patricia (December 2000). "Neohelos stirtoni, a new species of Zygomaturinae (Diprotodonta: Marsupialia) from the mid-Tertiary of the Northern Territory, Australia". Records of the Queen Victoria Museum Launceston. 105: 1–47.
  2. 1 2 3 4 Black, K.H.; Archer, M.; Hand, S.J.; Godthelp, H. (2013). "Revision in the diprotodontid marsupial genus Neohelos: Systematics and biostratigraphy" (PDF). Acta Palaeontologica Polonica. 58 (4): 679–706. doi: 10.4202/app.2012.0001 .