10 100 conch diameter / mm
• 'Manticoceras lyaiolense' O 'Manticoceras sinuosum' O 'Manticoceras affine'
• 'Manticoceras solnzevi'
• 'Timanoceras ellipsoidale'
Fig. 3.12. Bivariate diagrams showing the ontogenetic development of the whorl expansion rate (WER; in A), flank convergence index(FCI; in B), conch width index(CWI = ww/dm; in C), and umbilical width index (UWI = uw/dm; in D) of sectioned specimens of manticoceratid ammonoids from the Timan, the South Urals, and the Altay Mountains. Cross sections after Bogoslovsky (1969), x 0.75.
Similar conch morphologies are represented, and the specimens of Timanoceras ellipsoidale and Sphaeromanticoceras affine are clearly distinguished by their stout conchs. It is practically impossible to separate the two species Manticoceras sinuosum and M. solnzevi in terms of morphometrics.
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