Acmopyle grayae

Name

Acmopyle grayae

Rank

Species

Generic Name

[Genus] Acmopyle

Authors (Pub.)

Andruchow-Colombo A. Rossetto-Harris G. Brodribb T. J. Gandolfo M. A. Wilf P.  

Publication

A new fossil Acmopyle with accessory transfusion tissue and potential reproductive buds: direct evidence for ever-wet rainforests in Eocene Patagonia [2023/8]

Journal

American Journal of Botany

Volume

110(8)

Issue

e16221

Page number

6

Year

2023

Fossil Status

foliage

Stratigraphy

Ypresian

Strat. comment

La Huitrera Formation

Location

Laguna del Hunco quarry, Patagonia, Chubut, Argentina

Paleoregion

America (South)

Data for Holotypus

Repository

Museo Paleontologico Egidio Feruglio, Trelew, Argentina

Repository Number

MPEF‐Pb 16508a, b

Num

2

Pub.

A new fossil Acmopyle with accessory transfusion tissue and potential reproductive buds: direct evidence for ever-wet rainforests in Eocene Patagonia [2023/8]

Data for Paratypus

Repository

Museo Paleontologico Egidio Feruglio, Trelew, Argentina

Repository Number

MPEF‐Pb 16500–16501 (AL1 locality); MPEF‐Pb 16502 (LH01); MPEF‐Pb 468a, b (LH04); MPEF‐Pb 16503a,b–16504 (LH06); MPEF‐Pb 16506–16507, MPEF‐Pb 16509a,b–16510a,b, MPEF‐Pb 16511–16518a,b, MPEF‐Pb 16519 (LH13); MPEF‐Pb 16520 (LH15); MPEF‐Pb 16521 (LH22); MPEF‐Pb 16522–16523a,b (LH23); MPEF‐Pb 16525a,b (LH25); MPEF‐Pb 16528–16530, MPEF‐Pb 16533–16534a,b, MPEF‐Pb 16535a,b, MPEF‐Pb 16537a,b, MPEF‐Pb 16539–16540a,b (LH27), MPEF‐Pb 16541 (LH29)

Diagnosis

Leafy shoots heterophyllous with three leaf types: bifacial scale‐like, transitional, and bilaterally flattened mature leaves. Leafy shoots with up to four scale‐like leaves at the base, followed by up to five transitional leaves, and by 19–42 bilateral leaves per side of the branch. Complete leafy‐shoot length 44–103 mm; maximum width 13–36 mm, located at 17%–49% of the total length of the leafy shoot. Scale‐like leaves in helical phyllotaxy; mostly bifacially flattened, adpressed, triangular; base decurrent, apex acute; length 2–3 mm, width 0.5–1 mm. Transitional leaves in a helical to pseudodistichous phyllotaxy; tetragonal in cross section to bilaterally flattened, straight to slightly spreading; length 2–6 mm, height 0.5–2 mm. Mature leaves with opposite to alternate arrangement on the shoots; lanceolate to falcate; with a slightly asymmetric general outline and strongly asymmetrical apex; single veined; relatively expanded; bilaterally flattened; length 4–17 mm, height 1–3 mm; insertion angle of 50°–85°; leaf base decurrent with its lower side extending basally 1–4 mm and its upper side with a constriction; leaf apex keeled, asymmetrical, apiculate, straight or slightly curved upward. Accessory transfusion tissue present in the mesophyll, emerging from both sides of the midvein, is composed of thin and elongated, closely spaced, subparallel elements. Two stomatal bands on one of the leaf surfaces, parallel to and occurring immediately alongside the midvein; stomatal bands 0.2–0.4 mm wide, bearing multiple stomatal rows. Stomatal orientation parallel to the major leaf axis.