Microderoceras
Encyclopedia
Microderoceras is a flat sided, evolute, radially ribbed Lower Jurassic ammonite belonging to the ammonitid
family Eoderoceratidae
and superfamily Eoderocerataceae
. Its whorls are subquadrangular in section; venter on the outer rim, rounded; sides with two rows if distinct spines, tubercles on internal molds, formed at either end of the ribs.
These shelled cephalopods, named by Alpheus Hyatt
in 1871, are part of the now extinct Ammonoidea, which are distinct from the shelled nautiloids still found living today.
Ammonitida
The Ammonitida is an order of more highly evolved ammonoid cephalopods from the Jurassic and Cretaceous time periods, commonly with intricate ammonitic sutures....
family Eoderoceratidae
Eoderoceratidae
The Eoderoceratidae is the ancestral and most primitive family of the Eoderocerataceae; lower Jurassic ammonite cephalopods, characterized by evolute, commonly serpenticonic, shells that had long body chambers and would have had no stable floating position; and thus resemble contemporary...
and superfamily Eoderocerataceae
Eoderocerataceae
Eoderocerataceae is a superfamily of true ammonites from the Lower Jurassic, comprising seven phylogenetically related families, characterized in general by having ribbed evolute shells that commonly bear spines or tubercles...
. Its whorls are subquadrangular in section; venter on the outer rim, rounded; sides with two rows if distinct spines, tubercles on internal molds, formed at either end of the ribs.
These shelled cephalopods, named by Alpheus Hyatt
Alpheus Hyatt
Alpheus Hyatt was an American zoologist and palaeontologist.- Biography :Alpheus Hyatt II was born in Washington, D.C. to Alpheus Hyatt and Harriet Randolph Hyatt...
in 1871, are part of the now extinct Ammonoidea, which are distinct from the shelled nautiloids still found living today.