''Durotrigensia'' is a genus of ammonites (
Ammonitida) in the
perisphinctoid family
Parkinsoniidae.
''Durotrigensia'' is sometimes considered a subgenus of ''
Parkinsonia'' and is related also to ''
Oraniceras'' and ''
Okribites
''Okribites'' is a perisphinctoidean ammonite from the middle Jurassic of the Republic of Georgia
A republic () is a "state in which power rests with the people or their representatives; specifically a state without a monarchy" and also ...
''.
These cephalopods lived during the
Bajocian stage of the Middle
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...
some 170 to 164 million years ago.
Description
These large to giant ammonites have sharp and finely ribbed inner whorls and smooth outer whorls, without tubercles or lappets.
References
*
Ammonites - ''Parkinsonia'' (''Durotrigensia'') sp. entry
Jurassic ammonites
Bajocian life
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