Juraphyllitidae is a family of
Lower Triassic phylloceratin ammonites from Europe, North Africa, and Asia characterized by narrow, evolutely coiled shells, usually with coarse ventral ribbing on the body chamber. The first lateral saddles in the suture are diphyllic, with two terminal branches, others exposed sutural saddles are diphyllic or triphyllic, those covered by successive whorls being monophyllic. A few genera are more involute, with successive whorls partially embracing the flanks of the previous. All are compressed and a few lack ribbing.
The Juraphyllitidae are probably derived from the Late Triassic
Discophyllitidae and independent from the
Phylloceratidae.
They apparently left no descendants.
Eight genera are included:
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Juraphyllites
Juraphyllites is a genus of ammonites belonging to the family Juraphyllitidae.
Fossil record
These ammonites lived in the Jurassic from Sinemurian to ToarcianTragophylloceras
''Tragophylloceras'' is an extinct genus of cephalopod belonging to the Ammonite
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, ...
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Dasyceras
''Dasyceras'' is an early phylloceratid from the Sinemurian
In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.3 ± 2 Ma and 190.8 ± 1.5 Ma (million ...
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Schistophylloceras''
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Paradasyceras''
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Meneghiniceras''
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Harpophylloceras''
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Galaticeras''
Distinctions are based on variations in overall form including nature of ribbing, ventral surface, and degree of involuteness.
References
{{Taxonbar, from=Q6314885
Ammonitida families
Phylloceratina
Early Jurassic first appearances
Early Jurassic extinctions