von Bitter, P.H. & Norby, R.D. 1994 10 15: Fossil epithelial cell imprints as indicators of conodont biology.
Size and growth characteristics of microsculpture polygons on the cup nodes of the bladelike Pa elements of the conodont Lochriea commutata support the hypothesis that they are epithelial cell imprints. They are ˜2–6 pn wide and ˜4–10 pn long and are the same size throughout growth of the element. The epithelial imprints increased in number with growth, either linearly or periodically; the latter possibility may be important for defining specific growth stages of conodont elements. The imprint location on the top of nodes suggests that the latter were tissue-covered and that the scissor-model of function applies to these bladelike Pa elements. The location of the imprints also reflects evolutionary history: a probable ancestor, L. cracoviensis (Belka), also lacks a platform and possesses well-developed microsculpture polygons on broad cup nodes. Finally, correlation between internal white matter and external microsculpture suggests that internal osteocytes may have supplied the external secreting cells with calcium phosphate from the inner storage bank. Conodont biology, fossil epithelial imprints, polygonal microsculpture, Carbonferous, Lochriea commutata.