Geinitzia reichenbachii Hollick & Jeffrey 1909
Creators: name: Moreau, Jean-David
name: Néraudeau, Didier
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Pinopsida
Coniferales
Geinitziidae
Geinitzia
Geinitzia reichenbachii

description: Geinitzia reichenbachii (Geinitz, 1842) Hollick & Jeffrey, 1909
(Fig. 3 H-J)
Geinitzia reichenbachii Geinitz, 1842: 98. – Kunzmann 2010: 125- 126 [cum syn.].
MATERIAL. — Two specimens: IGR-23248; IGR-23249.
DESCRIPTION
The largest specimen (IGR-23248) is 50 mm long and 25 mm wide (Fig. 3H, I). Shoot is up to twice branched. Branches arise at up to 40°. Leafy shoots are up to 13 mm in diameter and straight. Leaves are helically arranged (Fig. 3H, I). They are elongated, falcate and show a long free part that forms an angle of up to 50° with the main axis of the shoot(Fig. 3H, I). Leaves are up to 14 mm long and up to 1.5 mm wide. The leaf margin is entire. The apex of leaves is acute and slightly curved inward to slightly recurved outwards (Fig. 3H, I). Leaves are rhomboidal to triangular in transverse section (rhomboidal at the base, triangular at the apex; Fig. 3J).
REMARKS
Specimens are preserved as charcoalified compressions, the cuticle is not preserved.
The gross morphology of Geinitzia shows some similarities with several Cretaceous conifers such as Cunninghamites C.Presl in Sternberg, 1838 and Elatocladus T.Halle, 1913 (elongated, lanceolate, helically arranged leaves forming an acute angle with the main axis of the twig). Geinitzia differs from Elatocladus by the absence of contraction at the leaf base (Kvaček 1999). Leaves of Geinitzia differ from Cunninghamites in having a triangular to quadrangular form in cross section, not flattened needles (Kvaček 1999; Herman & Kvaček 2010).
Although the gross morphology of leaves of Geinitzia formosa Heer, 1871 from the Cretaceous of Germany (Heer 1871) and those of G. reichenbachii are quite similar (Kunzmann 1999), they differ in size, G. formosa showing smaller leaves (Kunzmann 1999; Herman & Kvaček 2010). Geinitzia rigida (J.Phillips) T.M.Harris from the Middle Jurassic of Yorkshire (Harris 1979) differs from G. reichenbachii in having smaller and shorter leaves, with rounded adaxial and abaxial surfaces, and a slightly incurved apex. Geinitzia divaricata (Bunbury) T.M.Harris from the Middle Jurassic of Yorkshire differs from G. reichenbachii in showing well-spaced and never crowded leaves arising perpendicularly (Harris 1979). Geinitzia reichenbachii is a common member of Cretaceous floras from western France.This species was reported from numerous Albian (Lower Cretaceous) to Senonian (Coniacian-Maastrichtian; Upper Cretaceous) palaeobotanical sites, particularly in the Charente, Charente-Maritime, Dordogne, Maine-et-Loire and Vienne departments (e.g. Néraudeau et al. 2005, 2020a; Saint-Martin et al. 2013; Moreau et al. 2021).
description: Published as part of Moreau, Jean-David & Néraudeau, Didier, 2023, Amber and plants from the Upper Cretaceous of La Gripperie-Saint-Symphorien (Charente-Maritime, Western France), pp. 455-466 in Comptes Rendus Palevol 22 (20) on page 460, DOI: 10.5852/cr-palevol2023v22a20, http://zenodo.org/record/8074135