Ussurites
Encyclopedia
Ussurites is an extinct ammonoid cephalopod genus belonging to the suborder Phylloceratina
Phylloceratina
The Phyllocertina comprise a suborder of ammonoid cephalopods, belonging to the Ammonitida, whose range extends from the Lower Triassic to the Upper Cretaceous...

 and is included in the family Ussuritidae
Ussuritidae
Ussuritidae are ancestral, Triassic, Phylloceratina characterized by generally smooth, discoidal, evolute shells with rounded venters and little or no ornamentation and by sutures with primitive monophyllitic saddles with a single terminal branch or leaflet....

. Its range is restricted to the early Middle Triassic, (Anisian
Anisian
In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from 245 million years ago until 237 million years ago, approximately...

)

As with the family, the shell of Ussurites is discoidal, evolute, and generally smooth. The suture is phylletic with divided lobes and simple, rounded, elongate saddles. The ventral lobe is bifurcated, the two branches sharply serrated. The two lateral lobes are asymmetrically trifurcated, sections sharply pointed. The first lateral saddle (closest to the venter) is fairly evenly rounded, the second and third are narrower and asymmetric, leaning away from the venter and toward the umbilicus.

Monophylites, which extends through the Middle Triassic into the Carnian
Carnian
The Carnian is the lowermost stage of the Upper Triassic series . It lasted from about 228.7 till 216.5 million years ago . The Carnian is preceded by the Ladinian and is followed by the Norian...

is similar, differing in the details of the suture.
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