''Megacyon merriami'', or Merriam's dog, was a prehistoric canid that lived on the island of

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

in Indonesia during the Early Pleistocene. Its scientific name means "Merriam's large dog".

Description

''Megacyon'' was relatively larged sized, with an estimated body mass of around , comparable to a grey wolf. In comparison to its ancestor ''Xenocyon'', the

hypocone A cusp is a pointed, projecting, or elevated feature. In animals, it is usually used to refer to raised points on the crowns of teeth. The concept is also used with regard to the leaflets of the four heart valves. The mitral valve, which has ...

on the teeth was larger.

Ecology

''Megacyon'' is thought to have been a

hypercarnivore A hypercarnivore is an animal that has a diet that is more than 70% meat, either via active predation or by scavenging. The remaining non-meat diet may consist of non-animal foods such as fungi, fruits or other plant material. Some extant exampl ...

that preyed on large-sized prey such as deer.

Taxonomy and evolution

''Megacyon'' is thought to have evolved from mainland species of ''

Xenocyon ''Xenocyon'' ("strange dog") is an extinct group of canids, either considered a distinct genus or a subgenus of ''Canis''. The group includes ''Canis'' (''Xenocyon'') ''africanus'', ''Canis'' (''Xenocyon'') ''antonii'' and ''Canis'' (''Xenocyon'') ...

,'' with ''Megacyon'' being even larger than mainland ''Xenocyon'' species. Some authors have subsumed ''Megacyon'' into ''Xenocyon''. ''Megacyon'' is thought to be the ancestor of the much smaller '' Mececyon'' known from younger deposits on Java. Megacyon are currently around the 49-54 kilogram size range due to their evolution and niche overlapping with tigers. As tigers and Megacyon had a 100% niche overlap, Megacyon evolved to be smaller in size in order to avoid this niche overlap for the species survival.

References

* Schutt, 1973. Pleistozane Caniden (Carnivora, Mammalia) aus Java. Verhandelingen Koninklijke Akademie van der Wetenschappen (Series B), 76: 446–71. * Lyras G.A., Van der Geer A.A.E., Rook L., 2010. Body size of insular carnivores: evidence from the fossil record. Journal of Biogeography, 37 (6): 1007–21. * Volmer, Rebekka, et al. “Niche Overlap and Competition Potential among Tigers (Panthera Tigris), Sabertoothed Cats (Homotherium Ultimum, Hemimachairodus Zwierzyckii) and Merriam’s Dog (Megacyon Merriami) in the Pleistocene of Java.” Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 441, 2016, pp. 901–11. Extinct animals of Indonesia Pleistocene carnivorans Prehistoric canines {{canid-extinct-stub