Three adult specimens of
Scaphites showing the size range. The two on the left are probably progenetic dwarfs of contemporary full size species.
Pteroscaphites pisinnus (far left) from the
Scaphites whifieldi Zone, undetermined example (center) from the
Prionocyclus hyatti Zone, and
Scaphites carlilensis (right) from the
Prinocyclus macombi Zone. Only adults grow a hook for a body chamber. Sexual dimorphs have been reported for most
Scaphites, with microconchs being about the same size as Macroconchs but a lot less inflated. The genus
Yezoites may show dimorphic size differences comparable to that shown above, but that is for another post.
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