Brachyphyllum elegans Zheng Y.Cao

Plant Fossil Names Registry Number: PFN002726

Act LSID: urn:lsid:plantfossilnames.org:act:2726

Author: Z. Cao

Rank: species

Genus: Brachyphyllum Brongn.

Reference: Cao, Z. (1989): Some Lower Cretaceous gymnospermae from Zhejiang with study of their cuticules. – Acta Palaeontologica Sinica 28(4): 435–446., link

Page of description: 439, 443

Illustrations or figures: pl. 2, figs 8–11, pl. 3, figs 1–3

Types

Original diagnosis/description

A fragment of shoot about 2 mm wide and about 2.1 cm long, unbranched. Leaves triangular, arranged in a simple helix, adpressed; each with a commonly obtuse apex in surface view, typically 3 mm long and 2 mm wide. Leaves thick. Adaxial surface of leaf slightly concave; abaxial surface strongly convex but not keeled, slightly curved inwards, merging into cushion and bearing about fourteen pitted lines converging towards the apex of leaf.
Lower cuticle very thick. Stomata arranged in a longitudinal row arising above the general level, with 6–10 rows per mm; stomatal rows separated by up to five longitudinally rectangular cells measuring 25–45 μm long and 20–30 μm wide; epidermal cells within the stomatal row transversely wide in outline, not more than four
in number between the adjacent stomata; subsidiary cells of adjacent stomata often in contact but not sharing with each other. Anticlinal walls thick, attaining a thickness of 5–10 μm. Subsidiary cells 6–8 (?) in number, unspecialized, forming a round or elliptical ring measuring 70–90 μm in diameter. Guard cell unpreserved. Papillae absent.
In external appearance this species is very similar to Brachyphyllum obseum originally described from the Lower Cretaceous strata in Portugal and later reported from the Jurassic and Cretaceous rocks of other localities, but differs in the slender shoot, the relatively narrower and loosely disposed leaves. In the latter the shoot is stout and bears broadly triangular and crowded leaves, and the cuticular feature is not clearly known.
The cuticular structure of the present specimen closely resembles the preparation marked with code no. 36confBRC instead of the specific name given by Oldham (1976). According to Oldham’s study, the latter may be comparable with the preparation from the specimen determined as B. obseum by Seward (1895) ; unfortunately, the cuticle of Sewarďs specimen is too badly preserved for the accurate correlation between the cuticular features of both specimens. The English specimens are slightly different from the typical specimen of Brachyphyllum obseum but superficially identical with ours. It is difficult to say whether both specimens belong to the same species before the cuticular features of the English specimen have been better recognized.

Stratigraphy

Cretaceous, Lower Cretaceous
Shouchang Formation

Locality

China
Pingshan, Lin'an County, Zhejiang Province