GIN4843 Rarytkinia amaamensis Moiseeva  

Notes

Moiseeva (2012)

 

Locality

Amaam Lagoon

 

Description

From Moiseeva (2012) (p. 86)

"Leaves simple, entire, medium to large in size, 5.0–13.5 cm long and 3-8 cm wide; most abundant leaves are 9–11 cm long and 5–7 cm wide. Leaf lamina symmetrical, elliptic or ovate, most wide in the middle or somewhat lower. Length/width ratio close to 2:1. Leaf base narrow or broad cuneate, decurrent. Upper part of leaves narrows gradually beginning approximately from the middle. Apex acute, occasionally rounded at the tip.

Margin serrate or undulate, teeth sparse, irregularly spaced; leaf base entire-margined as a rule. Small broadly triangular teeth up to 1.5 mm high and 3–4 mm wide, slightly asymmetrical, apically pointed. Tooth apex acute or rounded, some times with glandule.

Venation pinnate, craspedodromous or semicraspedodromous. Secondary veins mostly bifurcate near margins so that one veinlet ends at the tooth apex, whereas the other one forms a loop connecting with the higher veinlet. Midrib thick and straight. Secondary veins (7–12 pairs) alternately depart from midrib at the angle close to 50°. In the distal part of leaf, thinned veins curve upward. Two to three pairs of lower secondary veins are connivent, thinner and shorter than higher veins. The pair of veins fourth or fifth from
below is best developed, having one to three basiscopic branches near the leaf margin. Sparse tertiary venation alternate-percurrent, with tertiaries orthogonal to secondaries. Venation of the fourth order in a form fine polygonal network."

Remarks

From Moiseeva (2012) (p. 86)

"Holotype: GIN RAS, no. 4843/248; The Amaam Lagoon area, Skalistyi Creek, occurrence locality 7; upper subformation of the Koryak Formation, upper Maastrichtian (Moiseeva, 2008, pl. X, fig. 3, Fig. 3a)."