''Sinomastodon'' ("Chinese mastodont") is an extinct

gomphothere Gomphotheres are an extinct group of proboscideans related to modern elephants. First appearing in Africa during the Oligocene, they dispersed into Eurasia and North America during the Miocene and arrived in South America during the Pleistocene a ...

genus (of order

Proboscidea Proboscidea (; , ) is a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. Three l ...

) known from the Late

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

to Early

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

of Asia, including China, Japan, Thailand, Myanmar, Indonesia and probably

Kashmir Kashmir ( or ) is the Northwestern Indian subcontinent, northernmost geographical region of the Indian subcontinent. Until the mid-19th century, the term ''Kashmir'' denoted only the Kashmir Valley between the Great Himalayas and the Pir P ...

. Extinct animals of Indonesia

Description

''Sinomastodon'', in comparison to earlier gomphotheres, had a shortened (brevirostrine) lower jaw that lacked permanent tusks/incisors. The skull was proportionally relatively short. The upper tusks, which are circular in cross-section, are upward curving and lack enamel bands. The molar teeth were triolophodont and

bunodont The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth ...

. One individual of ''S. hanjiangensis,'' suggested to about 30-years-old, is estimated to have been about tall and weighed .

Taxonomy and evolution

The taxonomic position of ''Sinomastodon'' is disputed. Some authors suggest that ''Sinomastodon'' originated from North American gomphotheres that migrated into Asia. Position according to Mothé et al. 2016 supporting this hypothesis, showing ''Sinomastodon'' nested amongst North American gomphotheres: However, the teeth of the earliest ''Sinomastodon'' species from the Late Miocene are zygodont, a morphology unknown in North American gomphotheres. Therefore is it is alternatively suggested that it derived from an Asian species of ''

Gomphotherium ''Gomphotherium'' (; "nail beast" for its double set of straight tusks) is an extinct genus of gomphothere proboscidean from the Neogene of Eurasia, Africa and North America. It is the most diverse genus of gompothere, with over a dozen valid sp ...

'', such as ''G. subtapiroideum'' or ''G. wimani.'' The earliest members of the genus appear during the Late Miocene, while the youngest members are known from the end of the Early Pleistocene, around 800,000 years ago.

Diet

Specimens of ''Sinomastodon'' from the Early Pleistocene of South China (''S. jiangnanensis'', ''S. yangziensis'') are suggested to have had

browsing Browsing is a kind of orienting strategy. It is supposed to identify something of relevance for the browsing organism. In context of humans, it is a metaphor taken from the animal kingdom. It is used, for example, about people browsing open sh ...

diet based on

dental microwear Dental microwear analysis is a method to infer diet and behavior in extinct animals, especially in fossil specimens. It has been used on a variety of taxa, including hominids, victoriapithecids, amphicyonids, canids, ursids, hyaenids, hyaenodont ...

analysis, while ''Sinomastodon bumiajuensis'' from the Early Pleistocene of Java is suggested based on stable carbon isotope analysis to have been a variable feeder, with the majority of specimens found to have a predominantly grazing diet.

References

* Tobien, H., Chen, G.F., and Li, Y.Q., 1986; Mastodons (Proboscidea, Mammalia) from the LateNeogene and Early Pleistocene of the People's Republic of China. Part I, HistoricalAccount. Mainzer geowiss, mitt., 15, pp. 119–181.

External links

{{Taxonbar, from=Q373271 Gomphotheres Miocene proboscideans Pliocene proboscideans Pleistocene proboscideans Cenozoic mammals of Asia Prehistoric placental genera Fossil taxa described in 1986