Lepidopteris scassoi

Name

Lepidopteris scassoi

Rank

Species

Generic Name

[Genus] Lepidopteris

Authors (Pub.)

Elgorriaga A. Escapa I. H. Cúneo N. R.  

Publication

Relictual Lepidopteris (Peltaspermales) from the Early Jurassic Cañadón Asfalto Formation, Patagonia, Argentina [2019/6]

Journal

International Journal of Plant Sciences

Volume

180

Issue

6

Page number

581

Year

2019

Fossil Status

foliage

Stratigraphy

Toarcian

Strat. comment

Cañadón Asfalto Formation

Location

Pomelo locality, Chubut Province, Patagonia, Argentina

Paleoregion

America (South)

Data for Holotypus

Repository

Museo Paleontologico Egidio Feruglio, Trelew, Argentina

Repository Number

MPEF-Pb 10378

Num

fig. 1A

Pub.

Relictual Lepidopteris (Peltaspermales) from the Early Jurassic Cañadón Asfalto Formation, Patagonia, Argentina [2019/6]

Diagnosis

Fronds bipinnate to tripinnatifid, lanceolate, with the larger pinnae occurring below the midpoint of the frond. Main rachis bearing 1–3 pairs of intercalary pinnules with entire to undulate margins between adjacent pinnae. Pinnae opposite to subopposite, linear, lanceolate, to narrow triangular, imparipinnate inserted at obtuse to right angles in the basal frond portion and increasingly acute angles toward the frond apex. Pinnules opposite to subopposite, with a decurrent fully attached base and obtuse apex. Pinnules inserted at subacute to acute angles, with entire to deeply dissected margins and basalmost lobes usually inserted to the pinnae rachis. Venation catadromous and pinnate with a prominent midvein; secondary veins opposite to subopposite, emerging at acute angles reaching the margins or lobes; third-rank veins rare, mostly near the margins. Fronds amphistomatic, with stomata more abundant on the lower leaf surface (0.5–0.7∶1 adaxial/ abaxial ratio). Stomata randomly oriented, monocyclic, with a ring of 4–9—usually 7—trapezoidal subsidiary cells bearing strong hollow papillae oriented toward, and partially occluding, the stomatal pit (papillae usually absent on rachides). Guard cells sunken, weakly cutinized. Ordinary epidermal cells straight walled, papillate, and polygonal isodiametric on pinnule lamina to more or less longitudinally elongate above rachis or pinnule midvein. Rachis mostly smooth, without macroscopic scales or lumps but with irregular epidermal pattern. Stomata on main rachis scarce, with subsidiary cells being commonly nonpapillate and not forming a ring.