Phylloceras
noun
Phyl·loc·er·as
fə̇ˈläsərəs
: a genus (the type of the family Phylloceratidae) comprising smooth involute compressed ammonites with complex sutures that occur first in the Triassic and are believed to have been ancestral to most Jurassic and Cretaceous ammonites
Word History
Etymology
New Latin Phyllocerat-, Phylloceras, from phyll- + -cerat-, -ceras -ceras