- Zhangheotherium
Taxobox
name = "Zhangheotherium"
fossil_range = EarlyCretaceous
image_width = 250px
image_caption = "Zhangheotherium quinquecuspidens" fossil displayed in Hong Kong Science Museum.
regnum =Animal ia
phylum =Chordata
classis =Mammal ia
unranked_ordo =Trechnotheria
ordo =Symmetrodonta
superfamilia =Spalacotherioidea
familia =Zhangheotheriidae
genus = "Zhangheotherium"
genus_authority = Hu, Y.Q. Wang, Luo & C.K. Li,1997
species = "Z. quinquecuspidens"
binomial = "Zhangheotherium quinquecuspidens"
binomial_authority = Hu, Wang, Luo & Li, 1997"Zhangheotherium" is a
genus ofsymmetrodont , an extinct order ofmammal s. Previously known from only the tall pointed crowned teeth, "Zhangheotherium", described fromLiaoning Province,China ,fossil s in1997 , is the first symmetrodont known from a complete skeleton. It was dated to between 145-125 million years ago in theCretaceous . A singlespecies , "Zhangheotherium quinquecuspidens", is presently known.Symmetrodonts and other archaic mammals such as
multituberculate s andmonotreme s are still being debated on their taxonomical relationships. "Zhangheotherium" has many primitive characteristics. Among them is a venomous spur at the foot, seen today in the modernplatypus . In addition, it walked with a reptilian sprawl, not at all like our known mammals but instead like manyMesozoic mammals, like "Jeholodens " and "Repenomamus ".The specimen GMV 2124 of the feathered dinosaur "
Sinosauropteryx prima " contained 2 jaws of "Zhangheotherium" in its stomach region (Hurum "et al." 2006). Thus, it seems to have preyed on this primitive mammal, possibly on a regular basis.References
*Hurum, Jørn H.; Luo, Zhe-Xi & Kielan-Jaworowska, Zofia (2006): Were mammals originally venomous? "Acta Palaeontologica Polonica" 51(1): 1–11. [http://www.app.pan.pl/acta51/app51-001.pdf PDF fulltext]
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