Rahul Sharma (Editor)

Neohelos

Updated on
Edit
Like
Comment
Share on FacebookTweet on TwitterShare on LinkedInShare on Reddit
Kingdom
  
Animalia

Infraclass
  
Marsupialia

Subfamily
  
†Zygomaturinae

Rank
  
Genus

Class
  
Mammalia

Family
  
†Diprotodontidae

Phylum
  
Chordata

Order
  
Diprotodontia

Neohelos

Similar
  
Silvabestius, Kolopsis, Hulitherium, Zygomaturus, Nimbadon

Neohelos is an extinct diprotodontid marsupial, that lived from the early to middle-Miocene. There are four species assigned to this genus, N. 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.

Contents

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.

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:

  • four−cusped P3 with a tall, subcentral parametacone, a distinct anterior parastyle, a moderately developed protocone and a small to moderate (sometimes absent) hypocone;
  • tendency to develop a mesostyle on P3;
  • M1 with well−developed stylar cusp A, stylar cusp E and postmetacrista;
  • M1 with a square occlusal outline (except N. solus);
  • large interproximal contact between P3 and M1;
  • broad, lanceolate i1 with a ventrobuccal groove and longitudinal lingual crest;
  • and moderate epitympanic fenestra in the postglenoid cavity.
  • Classification

    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.

    Paleoecology

    Neohelos lived in the early to Middle Miocene of Queensland, Australia. It is one of few diprotodont genera that existed in Bullock Creek in both Riversleigh and Northern Territory, in the Wipajiri Formation.

    References

    Neohelos Wikipedia