General Abbreviations: 1 = primary vein 2 = secondary vein For additional definitions, please review the Manual of Leaf Architecture.

Transcription

1 General Abbreviations: 1 = primary vein 2 = secondary vein For additional definitions, please review the Manual of Leaf Architecture. Teeth One order of teeth- teeth are all the same size or vary in size continuously. Large and irregular teeth- teeth are large and spaced irregularly along the margin. >1 order of teeth- teeth have more than one distinct size. Large and regular teeth- teeth are large and spaced at regular intervals. Tiny teeth- tiny teeth may be difficult to see without a microscope. 1

2 Shape and Symmetry Leaf symmetric Drip tip- the apex of a leaf comes to a very dramatic and long point. A drip tip is generally an indicator of a wet climate as it enables water to drip off the leaf. Leaf asymmetric Basal extension present- the laminar tissue of the leaf extends below where the petiole inserts into the leaf Base asymmetric- the lower 25% of the leaf is not symmetric.. 2

3 Veins 1 pinnate w/acute basal 2 - a leaf with only one 1 vein, but 2 veins that rise from the base of the leaf. Can appear palmate - must measure vein gauge. Compound agrophics- leaf has more than two sets of agrophic veins. Agrophics on upper veins- agrophic veins appear on any costal 2 above the basal most 2. Thick 1 with respect to 2 - the 1 vein is > 5 times thicker than the 2 veins, especially near the base. Agrophics on basal veins- agrophic veins are on the lower veins (common). 3

4 Decurrent costal 2 - costal 2 branch from the 1 and either deflect the 1 course or appear to be stealing some of the gauge of the 1. Obtuse basal 2-2 at the base of the leaf create a wide angle with the primary (measure angle on apical side of leaf). excurrent costal 2-2 branch from the 1 without deflecting it. 2 basally crowded basal costal 2 veins are spaced more closely together than apical costal secondary veins. 4

5 Forking 2-2 o vein(s) forks to form two veins of similar gauge. Marginal vein absent- there is no vein of 2 o gauge on the margin of the leaf. This is very common. Intersecondary present- a vein that has a similar course to a 2 o vein, but has a smaller gauge and shorter course. 2 vein on the margin- a vein of 2 o gauge on the margin of the leaf. Rarely preserved in fossils but can sometimes be recognized by a dark coloring around the margin of the fossil. 5

6 Intramarginal vein- a vein that runs along the margin but has some laminar tissue between it and the margin. Closely spaced percurrent 3 present- a percurrent 3 crosses between two adjacent secondaries. They can be very straight or sinuous in their course but don t branch. 3 not opposite percurrent- 3 run between secondaries without directly connecting them. They may branch to form more tertiaries or veins of lower gauge. Fimbrial vein- a vein of tertiary gauge that runs along the margin of the leaf with no tissue between the vein and the margin. Difficult to see. 3 form spiderweb around base- 3 form a spiderweb pattern around the base where the petiole insertion point is the center of the web. 6

7 Naked base- basal veins run along lower margin of leaf before reintegrating into the laminar tissue. These can be 1 or 2 veins. Leaf is low ranking- Veins in the leaf are very disordered and irregular. This is not very common in fossil leaves. Diagnostic features- any features not mentioned here that may help another person identify the leaf. 7