Locality

USGS11493

69.328°  -153.011°

Ikpikpuk River Area, Tommy Creek

17-24 m high bluffs on the east side of Tommy Creek consists of coal beds overlain by a gray bentonitic clay.  This is capped by a gray siltstone and conglomerate.  Probably representing the Tuluvak Tongue of the Prince Creek Formation, this locality yielded abundant plant debris and some whole leaves from the siltstone.

Locality Map

Description

Leaf:  simple; symmetrical; shape unknown, probably ovate or wide ovate; apex missing; base missing; margin dentate, teeth with obtuse angular apices and shallow rounded sinuses, teeth slightly irregular in size and spacing; venation actinodromous suprabasal (im)perfect marginal; primary midvein moderate more or less straight; a-pectinal veins moderate, slightly weaker than the midvein, more or less straight, arising at an angle of approximately 40°; a-pectinal abmedials arising at angles of 45-50°, forked dichotomously once or twice before terminating at the medial veins of the teeth; the most basal abmedials forming weak b-pectinals giving off further, often forked, b-abmedials at angles of 50°; at least five pairs of more or less straight or slightly curved, moderate superior secondaries arise from the midvein at angles of approximately 40°, sometimes forked; inferior secondaries arising from midvein at 80°, recurved, tertiaries transverse percurrent, straight, sinuous or slightly convex, usually simple but sometimes forked joining abmedial side of secondary at right angles and admedial side at right or acute angles; fourth order veins straight or sinuous, percurrent between the tertiaries, sometimes forked with a tendency to form an orthogonal reticulum.

Remarks

These hamamelid leaves display a tendency towards palinactinodromy but are also reminiscent of extant euptelealean leaves.  They are clearly very similar to specimen USGS 11611.4 (form HAPLP154) but larger and with a greater number of simple, rather than forked, tertiary veins.  An identical architecture is seen in Smiley's (unpublished) Dicot 83 of Zones VI and VII (base).