Information:  - The Late Cretaceous (100.566 Ma) is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series. The Cretaceous is named after the white limestone known as chalk which occurs widely in northern France and is seen in the white cliffs of south-eastern England, and which dates from this time.  - The Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name.  - A cephalopod (pronounced or ) is any member of the molluscan class Cephalopoda (Greek plural , "kephalópoda"; "head-feet"). These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles (muscular hydrostats) modified from the primitive molluscan foot. Fishermen sometimes call them inkfish, referring to their common ability to squirt ink. The study of cephalopods is a branch of malacology known as teuthology.  - Utaturiceras is an upper Cretaceous ( Cenomanian ) ammonitid belonging to the family Acanthoceratidae and subfamily Mantelliceratinae . Utaturiceras is described in Matsumoto et al . 2003 as having a fairly large shell at maturity , with a body chamber about half a whorl in length ; whorls higher than broad and more or less involute ; ribs in juvenile stage genly flexious and unequal in length , longer ones arising from bullate umbilical tubercles ; shorter ones branched or intercalated ; adult shell ornamented by equally long ribs and weakening tubercles . The suture has somewhat phylloid saddle endings . Note that Matsumoto , et al. , follow Cobban and Kennedy in referring to the Ammonoidea as an order in the Cephalopoda rather than as a subclass as often done .  - Acanthoceratidae is an extinct family of acanthoceratoid cephalopods in the order Ammonitida, known from the Upper Cretaceous. The type genus is "Acanthoceras".  - The Ammonitida is an order of more highly evolved ammonoid cephalopods from the Jurassic and Cretaceous time periods, commonly with intricate ammonitic sutures.    Given the information above, choose from the list below the object entity that exhibits the relation 'taxon rank' with the subject 'utaturiceras'.  Choices: - branch  - class  - family  - form  - genus  - order  - series

genus