Sagenopteris trapialensis

Name

Sagenopteris trapialensis

Rank

Species

Generic Name

[Genus] Sagenopteris

Authors (Pub.)

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

Publication

Southern Hemisphere Caytoniales: vegetative and reproductive remains from the Lonco Trapial Formation (Lower Jurassic), Patagonia [2019/1]

Journal

Journal of Systematic Palaeontology

Annee/Jahrgang

2019

Issue

10.1080/14772019.2018.1535456

Page number

3

Year

2019

Fossil Status

foliage

Stratigraphy

Lower Jurassic

Strat. comment

Lonco Trapial Formation: Pliensbachian–Toarcian

Location

Taquetrén B locality, Chubut Province, Patagonia

Paleoregion

Gondwana (S America)

Data for Holotypus

Repository

Museo Paleontologico Egidio Feruglio, Trelew, Argentina

Repository Number

MPEF-Pb 2713a, b (Taquetrén B)

Num

2F, 4A, C, D, G

Pub.

Southern Hemisphere Caytoniales: vegetative and reproductive remains from the Lonco Trapial Formation (Lower Jurassic), Patagonia [2019/1]

Data for Paratypus

Repository

Museo Paleontologico Egidio Feruglio, Trelew, Argentina

Repository Number

MPEF-Pb 1864, 2034 (Taquetrén A) and MPEF-Pb 2854, 2855, 2877, 6608, 6623, 9506–9508, 9510–9512, 9514–9518, 9541 (Taquetrén B)

Num

Figs 2–4, 6A–C

Pub.

Southern Hemisphere Caytoniales: vegetative and reproductive remains from the Lonco Trapial Formation (Lower Jurassic), Patagonia [2019/1]

Diagnosis

Compound petiolate leaves bearing four leaflets, up to 58mm long and 18mm wide, with an average length/width (L/W) ratio of 2.5:1. The central pair of leaflets is nearly symmetrical, elliptic to obovate, emerging at 20–45; the lateral pair is smaller, asymmetrical, oblong to ovate, with an emergence angle of 75–90. Both types of leaflets have rounded apexes, straight to slightly undulate margins, occasionally with up to two lateral lobes. Petioles slender, with straight margins gently tapering upwards. Leaflets with a strong midrib, visible up to three- to four-fifths of leaflet length. Secondary veins emerging from midrib at c. 9–19, dichotomizing and anastomosing frequently forming obliquely oriented areolae with a L/W ratio of 8.5–11:1. Leaflets with anastomoses of Z, X, H and compound types, dichotomies simple. Bud- and scalelike leaves small, the former having a broad petiole with curved margins, clasping base and leaflets with diffuse venation; scale-like leaves with tapering upwards petioles with a broad base.