Trilobite Vogesina lacunafera
Vogesina lacunafera Trilobite
Devonian age (~390 million years ago)
Phacopida ("lens-face") is an order of trilobite that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse group of related suborders. The origin of the Phacopida order is uncertain. It comprises three suborders (Phacopina, Calymenina, and Cheirurina) which share a distinctive protaspis (developmental stage lacking segments) type. Superfamily Acastoidea. Cephalon: axial furrows slightly to moderately divergent, anterior glabellar lobes and furrows usually not fused (although furrows may be indistinct), eyes typically distant from posterior border furrows, but not strongly anterior; frontal glabellar lobe auxilliary impression system triangular in outline, maximum width of glabella adjacent to preglabellar furrow, median region of glabella devoid of muscle scars; cephalic margin "shouldered," laterally convex course of genal margin topographically distinct from curvature of axial margin. Thorax: pleural endings blunt, rounded, or angular, sometimes spinose. Pygidium: micropygous to subisopygous, sometimes spinose (expressed as marginal spines), pygidial axis with deep, apodemal anterior ring furrows, with abrupt transition to shallow posterior ring furrows; coincident decrease in angle of axial furrow convergence. Often similar in general body form to Phacopoidea via convergent evolution, but glabellar and other differences as noted above.
MY FOSSIL Collection - Dpaul7
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