Perisphinctes
noun
Peri·sphinc·tes
| \ ˌperəˈsfiŋ(k)(ˌ)tēz\
Definition of Perisphinctes
: a genus (the type of the family Perisphinctidae) comprising discoidal ammonites having bifurcating ribs not interrupted on the ventral side and being characteristic of the Upper Jurassic
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