Jeholodens


Jeholodens was a primitive mammal belonging to the order Eutriconodonta, and which lived in present-day China during the Middle Cretaceous about 125 million years ago.[1]

Jeholodens
Temporal range: Early Cretaceous, 125 Ma
Type specimen, Geological Museum of China
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Eutriconodonta
Family: Jeholodentidae
Genus: Jeholodens
Ji et al., 1999
Type species
Jeholodens jenkinsi
Ji et al., 1999

Only one specimen has been formally described. This specimen (the holotype) consists of a virtually complete articulated skull and skeleton, it shared its corporal characteristics with most other Mesozoic mammals; it was a long-tailed, nocturnal tetrapod (with prehensile fingers and toes) which hunted insects, its food, during the night.[1]

Possible specimen displayed in Hong Kong Science Museum
Restoration

It is suspected to be a nocturnal creature because it had very large eyes which were roughly 5 cm across. This would have allowed it to have better night vision for catching insects. It is notable for its relatively derived forelimb morphology, having shoulder blades and other pectoral girdle elements comparable to those of modern therians like opossums. It also had grasping hands. By contrast, however, the hindlimbs retained primitive characters, suggesting a sprawling stance.[1][2]

Recent studies show that it was specialised to an arboreal lifestyle, possessing prehensile hands.[3]

References

  1. Qiang, J.; Zhexi, L.; Shu-An, J. (1999). "A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton". Nature. 398 (6725): 326–30. doi:10.1038/18665. PMID 10192332.
  2. Zofia Kielan-Jaworowska, Richard L. Cifelli, Zhe-Xi Luo (2004). "Chapter 7: Eutriconodontans". Mammals from the Age of Dinosaurs: origins, evolution, and structure. New York: Columbia University Press. pp. 216–248. ISBN 0-231-11918-6.CS1 maint: multiple names: authors list (link)
  3. Meng Chen, Gregory Philip Wilson, A multivariate approach to infer locomotor modes in Mesozoic mammals, Article in Paleobiology 41(02) · February 2015 doi:10.1017/pab.2014.14