USGS 11601.1

  HA(PL)(D)144

USNM Number

406784

 

Locality

Latitude: 56.271111° N

Longitude: -158.656944° W

Chignik (B-2) Quad.
Collected by R.A. Spicer and J.A. Wolfe.
Floodpain swamp.  Lower part of Tolstoi Formation.

Locality Map

Geology

 

Description

Leaf:  simple; asymmetrical; narrow obovate; apex acuminate; base missing (decurrent?); margin serrate, teeth in the basal half of the lamina with obtuse apices and very shallow rounded sinuses, teeth in the apical half of the lamina 3-5 mm long with acute apices and rounded sinuses, teeth variable in size and spacing; venation suprabasal marginal imperfect actinodromous; primary midvein thin to moderate, straight; pectinal veins thinner than the midvein, slightly curved, arising at an angle of 40° one side and 50° on the other, pectinal abmedials departing at angles of approximately 50°, simple, shallowly curved, craspedodromous; superior secondary veins moderate, approximately 7 pairs, craspedodromous, straight or slightly curved, arising from the midvein at angles of 40-50°, branched abmedially near the margin, craspedodromous; tertiary veins transverse, simple or forked, straight, convex or sinuous; fourth order venation not visible.

 

Remarks

The venation of this leaf has very pinnate appearance although it is fundamentally actinodromous.  The tertiary venation displays a degree of disorganization unusual in leaves from the uppermost Cretaceous or lowermost Tertiary.  The course and degree of branching is very variable and, although fundamentally transverse, some areas develop into almost a random reticulum. Also of special interest is the difference in tooth size and shape between the basal and apical halves of the lamina.

This leaf form is very close to that described by Knowlton (1900) under the name 'Viburnum'? problematicum Knowlton (1900, p. 71; Plate 19, Fig. 4) and which Brown (1962) combined with 63 other species into 'Cissus' marginata (Lesquereux) Brown (1962, p. 79-81; Plate 53, Figs. 1-4, 6; Plate 54, Figs. 1-4; Plate 55, Figs. 4, 6, 7).  Brown included a wide variety of forms under this name with a stratigraphic range through the Upper Cretaceous and Paleocene.  It is extremely doubtful, however, that such a combination is justified or useful.