Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský 1887

Kvaček, Jiří, Gomez, Bernard & Zetter, Reinhard, 2012, The early angiosperm Pseudoasterophyllites cretaceus from Albian-Cenomanian of Czech Republic and France revisited, Acta Palaeontologica Polonica 57 (2), pp. 437-443 : 438-441

Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský 1887

Figs. 1–3 .

1874 Asterophyllites cretaceus ; O. Feistmantel 1874: 267 nomen nudum.

1887 Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský, 1887 ; Velenovský 1887: 643, figs. 19–25.

1889 Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský, 1887 ; Velenovský 1889: 44, 48, 52.

1901 Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský 1887 ; Frič and Bayer 1901: 87, fig. 37.

1926 Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský 1887 ; Velenovský and Vinklář 1926: 24, 53, pl. 2: 11, pl. 3: 6, 7, 9, 10.

1902 Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský 1887 ; Zeiller 1902: 11.

1954 Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský 1887 ; Teixeira 1954: 144, figs. 1, 2.

1963 Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský 1887 ; Němejc 1963: 318, text−fig. 167.

1997 Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský 1887 ; Uličný et al. 1997: 193.

2003 Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský 1887 ; Kvaček and Eklund 2003: 1033, fig. 12.

http://dx.doi.org/10.4202/app.2009.0060

Lectotype: designated here, NMP F 654 , Velenovský 1887: fig. 22 (refigured in Fig. 1A of this paper).

Type locality: Lipenec, Czech Republic.

Type horizon: Peruc Korycany Formation, Cenomaninan, Late Cretaceous.

Other material.—NMP F 654, NMP F 655, NMP F 656, NMP F 657, NMP F 1423, NMP F 2280, NMP F 2285, NMP F 2899, UL REN002.

Emended diagnosis.—Twigs branch 3–4 times. Axes consisting of nodes and internodes. Nodes consisting of two pairs of decussately arranged leaves very closely spaced forming semi−whorls. Lateral branches borne in leaf axils; branches either well developed or represented only by axilar bud. Leaves coriaceous, linear to cylindrical with rounded tip and broad, shortly decussate base. Leaves amphistomatic, bearing stomata in two distinct bands on adaxial and abaxial sides of leaf. Ordinary epidermal cells rectangular to isodiametric, with thick anticlinal walls, stomata paracytic with two narrow subsidiary cells and two exposed guard cells.

Dimensions.—Length of the axis: more than 110 mm; width of the axis: 0.5–3 mm; length of the leaves: 1–10 mm; width of leaves: 0.6–1 mm; length of guard cells: 20–24 µm; width of guard cells: 5–8 µm; length of epidermal cells: 20–35 µm; width of epidermal cells: 15–20 µm.

Description.—The lectotype specimen consists of 3 axes, each constructed of 4–6 nodes and internodes. Each axis is 10–15 mm long, and gives off leaves that are 7–9 mm long ( Fig. 1A, B ). Another specimen is 32 mm long ( Fig. 1F ). It shows axilary branching. Each branch possesses at least 5 nodes and internodes. The axis is longitudinally striate and 0.5–3 mm in diameter. The nodes consist of whorls of simple coriaceous linear leaves, which are wrinkled, suggesting that they were 3D cylindrical in vivo. Leaves are heavily cutinized and variable in size, i.e., 1−10 × 0.3−1 mm; they extend from the nodes in semi−whorls each consisting of two pairs very closely spaced of decussately arranged leaves. Lateral branches are given off in axilary position of each leaf. Branches may be well developed (i.e., real branches), or present only as axilar buds. The buds, together with the leaves, form rich semi−whorls. Due to their shape, the leaves do not possess clearly defined abaxial and adaxial sides. Stomata are arranged in two bands, probably one on the adaxial and one on the abaxial side. The stomata are oriented perpendicularly, longitudinally or obliquely to the leaf margin. The stomatal apparatus consists of two partly exposed guard cells (8–10 × 22–27.5 µm) and two narrow subsidiary cells (2–3 × 25–32.5 µm). Ordinary epidermal cells are isodiametric quadrangular or polygonal; their size is (8)–15–(20) × (8)–20–(25) µm ( Fig. 1C, D ). Anticlinal cell walls are straight (up to 3 µm in thickness). The periclinal walls are covered by small wrinkles and papillae, especially in parts close to the leaf margin ( Fig. 1E ).

Associated with the vegetative remains are stamens that are very similar in appearance to sterile leaves. Moreover, they possess the same epidermal cell pattern and idiocuticular features as the sterile leaves (compare Fig. 1D, E with Fig. 2E ). Stamens are ovoid−elongate, 3–3.5 mm long and 1–1.5 mm wide, massive, and not divided into an anther and filament showing a considerable amount of sterile tissues ( Fig. 2A ). They possess an apically expanded connective forming acute apical extensions ( Fig. 2D ), with a blunt apex bearing paracytic stomata. The stamens are tetrasporangiate and consist of two indistinct lobes. If macerated, each lobe shows two narrow pollen sacs ( Fig. 2B ) embedded in the tissue of the abaxial side of the stamen. Dehiscence is by longitudinal slits.

In situ pollen grains of the Tucanopollis type are sulcate, oblate to spheroidal, in polar view elliptic to circular, 18–24 µm in diameter ( Fig. 3A, C, D ). The aperture is broad and short, the membrane thin and often covered by echinate Ubisch bodies ( Fig. 3D ). The sculpture is psilate in LM, microechinate, perforate in SEM ( Fig. 2B ); exine thick (1.5–2 µm), nexine 0.8–1 µm, short columellae, tectum 1–1.2 µm .

Stratigraphic and geographic range.—Early to Late Cretaceous, Albian to Cenomanian. Czech Republic (Cenomanian): Pecínov, Praha−Hloubětín, Lipenec, Touchovice; France (Albian): Les Renardières, Tonnay−Charente, Charente−Maritime.

Figures

Fig. 1. Early angiosperm Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský, 1887 from the Late Cretaceous (Cenomanian) of Czech Republic. A. Lectotype, branched leafy axis, Lipenec, NMP F 654. B. Detail of lectotype, showing semi−whorled arrangement of leaves, Lipenec, NMP F 654. C. Leaf cuticle with stomata arranged perpendicularly, longitudinally, and obliquely to the leaf axis, Pecínov (unit 3), NMP F 2880a. D. External surface of paracytic stoma, Pecínov (unit 3), NMP F 2880a. E. Papillae in marginal part of the leaf, Pecínov (unit 3), NMP F 2880b. F. Axilary branches on a leafy twig, Pecínov (unit 3), NMP F 2880. Scale bars A, B 5 mm; C 100 µm; D, E 50 µm; F 10 mm.

Fig. 2. Early angiosperm Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský, 1887 from the Late Cretaceous of Pecinov (unit 3), Czech Republic (A, D, E; SEM photographs) and Les Renardières, France (B, C). A. Isolated stamen showing apical extension of connective, NMP F 2880c. B. Macerated stamen showing two pairs of pollen sacs, UL REN 001. C. Detail of macerated stamen showing pollen in situ, UL REN 002. D. Detail of the apical extension of connective, NMP F 2880c. E. Epidermis surface of the apical extension of connective showing paracytic stomata and papillae, NMP F 2880c. Scale bars: A 1 mm, B 0.5 mm, C 100 µm, D 150 µm, E 60 µm.

Fig. 3. Pollen Tucanopollis sp. from the stamen on Fig. 2C, which is associated with the vegetative parts of angiosperm Pseudoasterophyllites cretaceus O. Feistmantel ex Velenovský, 1887 from the Late Cretaceous of Les Renardières, France, specimens UL REN 002. A. Monosulcate pollen grain in situ showing irregular sulcus area. B. Microechinate, perforate exine sculpturing, detail of pollen exina. C. Monosulcate pollen grain in situ showing sulcus area. D. Pollen grain in situ showing Ubish bodies. Scale bars: A 10 µm, B–D 1 µm.