Stomata in Cretaceous fossils

Fig. 3. Ginkgo sp. A, TLM view of two stomatal complexes (SL5572, scale 1⁄4 50 mm); B, TLM view of single stomatal complex with at least four papillae (SL5572, scale 1⁄4 20 mm); C, SEM view of the inner cuticular surface showing one stomatal complex (S-1755, scale 1⁄4 10 mm); D, SEM view of the outer cuticular surface showing one stomatal complex with six papillae (S-1755, scale 1⁄4 10 mm).

Cretaceous plant fossils of Pitt Island, the Chatham group, New Zealand

by Pole M., Philippe M. (2010)

Mike Pole, Marc Philippe,

In Alcheringa: An Australasian Journal of Palaeontology, 34: 3, 231 — 263 – DOI: 10.1080/03115511003659085 –


Fig. 4. Araucariaceae: Araucaria rangiauriaensis sp. nov.; A, SEM view of a single leaf (S-1727, scale 1⁄4 1 mm); B, TLM view of stomatal zone (SL5575, scale 1⁄4 50 mm); C, SEM view of outer surface of a stomatal zone showing obliquely oriented stomata (S-1727, scale 1⁄4 20 mm); D, SEM view of the inner cuticular surface of a stomatal zone (SL5575, scale 1⁄4 20 mm); E, TLM view of typical epidermal cells (SL5575, scale 1⁄4 20 mm); F, TLM view of a single stomatal complex (SL5575, scale 1⁄4 40 mm).


Pitt Island, a part of the Chathams Islands group, lies 700 km east of New Zealand. Its geology includes the Tupuangi Formation, dated as Motuan to Teratan (late Albian to Santonian) on the basis of palynology. Samples of Tupuangi Formation mudstone yielded leaf cuticle assemblages dominated by araucarian and podocarp conifers and locally by angiosperms.

The 12 distinguishable conifer taxa include a new species of Araucaria, A. rangiauriaensis, and the extinct genera Eromangia, Kakahuia (both Podocarpaceae), Otwayia (Cheirolepidiaceae), Paahake (Taxodiaceae or Taxaceae) and possibly Katikia (Podocarpaceae).

Ginkgo and two types of dicotyledonous angiosperm cuticle are present. Based on the absence of bennettitaleans and rarity of Ginkgo, a Turonian or slightly younger age is inferred, making the Pitt Island assemblage the first Turonian plant macrofossils documented from New Zealand.

Fig. 9. Podocarpaceae: Kakahuia sp. A, TLM view showing scattered stomata and prominent papillae (SL5566, scale 1⁄4 50 mm); B, TLM view of a single stomata surrounded by papillae (SL5566, scale 1⁄4 20 mm); C, SEM view of outer surface showing stomata with stomatal pores very subdued (S-1749, scale 1⁄4 20 mm); D, SEM view of inner surface with many stomata (S-1749, scale 1⁄4 20 mm); E, F, TLM views of typical epidermal cells on non-stomatal surface (SL5566, scale 1⁄4 20 mm).

The fossils provide a window into southern high-latitude (polar) vegetation of the mid-Cretaceous. Conifer charcoal (probably of Podocarpaceae) is locally abundant and suggests that fire was an important part of the ecosystem. A broad analogy with modern boreal conifer-deciduous angiosperm forests is suggested although clearly with warmer temperatures

Fig. 11. Podocarpaceae sp. ‘chained’. A, TLM view of stomatal rows. Note darker staining (thicker) subsidiary cell cuticle (SL5642, scale 1⁄4 50 mm); B, TLM view of single stomatal complex showing strong rim. (SL5643, scale 1⁄4 20 mm); C, TLM view of stomatal rows (SL5643, scale 1⁄4 50 mm); D, TLM view (SL5711, scale 1⁄4 50 mm); E, SEM view of outer surface showing stomatal rows with prominent ring of raised subsidiary cells (S-1757, scale 1⁄4 20 mm); F, SEM view of inner surface of a stomatal complex (S-1757, scale 1⁄4 10 mm).


Stomata in fossil Swillingtonia

Description of plate 3
Stomata of Swillingtonia denticulata gen. et sp.nov., and of Aloe haemanthifolia,
photographed by s.e.m.
Figure 19. Part of stomatal band (magn. x 360). V61025.
Figure 20 and 21. Detail of intact stomata. The structures resembling guard cells are here
interpreted as paracytic subsidiary cells, overarching the guard cells proper, compare figure
34a, av 20, (magn. x 810). 21, (magn. x 1350). 20, 21: V61022a.
Figure 22. Partial collapse of outer periclinal walls of subsidiary cells reveals part of underlying
guard cells; compare figure 34a2, (magn. x 1530). V61024a.
F igure 23. Subsidiary cells intact, but guard cells beneath evident through the outer pore (magn.
x 1530).
F igure 24. Outer periclinal walls of subsidiary cells missing (as are those of the encircling cells
at left). Lips of guard cells evident through remains of the outer pore; cf. right-hand side
of figure 34a3, (magn. x 1530). V61021.
Figure 25. Collapse of subsidiary cells (compare figure 34a2) has opened the outer pore to reveal
the stomatal aperture beneath (magn. x 1620).
F igure 26. Stoma of a Recent Aloe haemanthifolia, showing the cuticular ledges simulating guard
cells, as do the subsidiary cells in Swillingtonia (magn. x 1080). From a negative made
available to us through the kindness of Dr D. Cutler. Crown Copyright, reproduced with
permission of the Controller, H.M.S.O. and the Director, Royal Botanic Gardens, Kew.

The earliest fossil conifer from the Westphalian B of Yorkshire

by Scott A. C., Chaloner W. G. (1983)

In Proc. R. Soc. Lond. B 220: 163-182 –

Figure 34. Reconstruction of stomata of Swillingtonia denticulata gen. et sp.nov. (magn.
x 1000). ( a-az). Plan and hypothetical sectional views of the stomata as interpreted in this
paper. This shows the two paracytic subsidiary cells (s.c.) overlying the guard cells (g.c.)
which are visible, in part, through the ‘ outer pore ’ of the stoma. The alternative possibility,
b, blt that the two outer structures are themselves the guard cells is rejected for reasons
given in the text. In the interpretation favoured here, a, ax, the cells shown external to the
subsidiary cells are encircling cells. a2 is a hypothetical section derived from ax, following
collapse of the subsidiary cell outer periclinal walls (compare figure 22). a3 corresponds to
collapse of one subsidary cell and erosion of the outer periclinal wall of the other
(compare figures 24, 25).


Stomata in fossils of South China Sea

Fig. 16. Light microscope photographs of selected stomatal structure morphologies. a, b: large epidermal stomatas; c-d: small epidermal stomatas (possibly broken from the large ones). 

Climatic or tectonic control on organic matter deposition in the South China Sea? A lesson learned from a comprehensive Neogene palynological study of IODP Site U1433

by Miao Y., Warny S., Clift P. D., Gregory M., Liu C. (2018)

Yunfa Miao, Chinese Academy of Sciences

Sophie Warny,Louisiana State University

Peter D. Clift, Louisiana State University

Mitch Gregory,

Chang Liu, Texas A&M University


In International Journal of Coal Geology 190:166-177 – DOI: 10.1016/j.coal.2017.10.003 –


Palynomorphs and other organic particles are basic key components of palynofacies, yet quantitative analyses of all types are rarely used together to investigate organic matter assemblage changes and evaluate the driving forces behind the observed changes. In this paper, eight organic-walled microfossil and particle morphologies (sporopollen, Pediastrum, Concentricystes, fungi, dinoflagellate cysts, structured/amorphous organic matters, stomatal apparatus and scolecodonts) are tabulated and their concentrations and fluxes are evaluated over the past 17 million years (Ma) in sediments recovered from the South China Sea at International Ocean Discovery Program (IODP) Site U1433. Overall, these morphologies show roughly similar increasing trends but with different levels of fluctuations. The uniform increase in all morphologies at ∼. 8. Ma (named the ∼. 8. Ma event) is the most notable feature of the past 17. Ma. To explain the trend, and because these various organic matters reflect various environmental conditions, we argue that the uniformity of the signal implies that tectonically-driven basin and drainage evolution played the key role, rather than paleoclimate (Asian summer monsoon). The ∼. 8. Ma event was likely triggered by the onset of the Mekong River in its present location, although the role of monsoon evolution cannot be excluded completely.

Stomatal ontogeny and structure of the fossil pteridosperm Sagenopteris (Caytoniales)

The stomatal ontogeny and structure of the liassic pteridosperm Sagenopteris (Caytoniales) from Hungary

by Barbacka M., Bóka K. (2000)

Maria Barbacka, K. Bóka,


In International Journal of Plant Sciences 161(1): 149-157 –


Stomatal ontogeny is often inferred but rarely documented for extinct fossil plants because it requires observations from young leaves that are rarely preserved as fossils.

The discovery of several very young leaves of the Jurassic plant Sagenopteris (Caytoniales) in the Mecsek Mountains (southern Hungary) in a good state of preservation provides the opportunity for studying the stomatal ontogenesis of this genus.

The specimens show perigenous anomocytic stomata. This feature confirms the evolutionarily high position of Sagenopteris among fossil gymnosperms and supports the opinion that the ancestors of angiosperms and some groups of pteridosperms might be closely related.

Such clear examples of stomatal development have not previously been documented for fossil material.

Stomata in Early Cretaceous Angiosperms (fossils)

Cuticle Evolution in Early Cretaceous Angiosperms From the Potomac Group of Virginia and Maryland

by Upchurch G. R. Jr. (1984)

Garland R. Upchurch Jr.

U.S. Geological Survey, Denver, Colorado, USA


In Annals of the Missouri Botanical Garden 71(2: 522-550 –


Studies of angiosperm leaf cuticles from the Lower Cretaceous Potomac Group reinforce previous evidence for a Cretaceous adaptive radiation of the flowering plants and suggest unsuspected trends in the evolution of stomata and trichomes.

Early Potomac Group angiosperm leaf cuticles (Zone I of Brenner or Aptian?) show little interspecific structural diversity, particularly in stomatal organization. All species conform to the same highly plastic pattern of variation in subsidiary cell arrangement, in which the stomata on a single leaf conform to several types, including paracytic, hemiparacytic, anomocytic, laterocytic, and weakly cyclocytic.

Several species resemble extant Chloranthaceae and Illiciales, but none represents a modern family. Later leaves (Subzone II-B of Brenner, or Albian) exhibit greater interspecific structural diversity, particularly in stomatal organization.

Three new patterns of variation in subsidiary cell arrangement are present in addition to the older one and each has a subset of the variation present in the older pattern. Cuticular anatomy is consistent with proposed leaf affinities to Platanaceae and Rosidae. The stratigraphic trend in cuticle types supports the concept that the subclass Magnoliidae includes the most primitive living angiosperms. However, it also suggests that the uniformly paracytic stomatal pattern characteristic of Magnoliales, generally considered primitive for the flowering plants, may actually be derived from the variable condition found in Zone I leaves.

Stomata in Kunduriphyllum kundurense (fossil Platanaceae)
Fig. 3. Arrangement of stomata on the lower surface of a leaf Kunduriphyllum kundurense gen. et comb. nov., specimen GIN, no. 4867-16/3-115a: (a) incrustation, SEM, showing stomata varying in size; (b) drawing over figure 3a.

Kunduriphyllum kundurense gen. et comb. nov. (Platanaceae) and Associated Reproductive Structures from the Campanian of the Amur Region, Russia

by Kodrul T. M., Maslova N. P. (2017)

T. M. Kodrul a, b, * and N. P. Maslova c

a Sun Yat-sen University, Xingang Xi Road 135, Haizhu District, Guangzhou, 510275 China

b Geological Institute, Russian Academy of Science, Pyzhevsky per. 7, Moscow, 119017 Russia

c Borissiak Paleontological Institute, Russian Academy of Science, Profsoyuznaya ul. 123, Moscow, 117647 Russia


In Paleontological Journal 51(14): 1584-1596 – DOI: 10.1134/S0031030117140027 –
Fig. 4. Epidermis of a lower leaf surface of extant Platanus acerifolia (Aiton) Willd., herbarium of N.P. Maslova, SEM: (a) outer view showing stomata varying in size; (b) inner view showing differently sized anomocytic and laterocytic stomata.


Fossil leaves and associated reproductive structures from the Kundur locality, Amur Region, are examined. A new genus of the unlobed platanaceous leaves, Kunduriphyllum gen. nov. (Platanaceae) is described based on distinctive morphological and epidermal features.

The similarity of epidermal characteristics and identical biological damage suggest that the leaves Kunduriphyllum kundurense gen. et comb. nov., staminate inflorescences Kundurianthus, and infructescences Kunduricarpus could be assigned to a single plant.

Stomata in sun and shade leaves of fossil Liquidambar species

Figure 3. Epidermal characters of leaves of Liquidambar chinensis, SEM. A, B, C, Cuticle of lower surface of shade leaf. A, Outer view, thin folded cuticle, borders of ordinary epidermal cells are imperceptible. B, C, Inner view showing paracytic stomata and sinuous anticlinal walls of ordinary epidermal cells. D, E, F, Cuticle of lower surface of sun leaf. D, Outer view, cuticle is thick, borders of ordinary epidermal cells are distinct. E, F, Inner view, showing paracytic stomata and straight anticlinal walls of ordinary epidermal cells. Scale bar, 50 μm (A, B, D, E) and 20 μm (C, F).

Sun and shade leaf variability in Liquidambar chinensis and Liquidambar formosana (Altingiaceae)

by Maslova N. P., Karasev E. , Kodrul T. M., Spicer R. A., Liu X. (2018)

  • N. P. Maslova, Russian Academy of Sciences
  • Eugeny V. Karasev, Russian Academy of Sciences
  • T. M. Kodrul, Russian Academy of Sciences
  • Robert A. Spicer, The Open University (UK)
  • Xiaoyan Liu, Sun Yat-Sen University


In Botanical Journal of the Linnean Society 90:1-20 – DOI: 10.1093/botlinnean/boy047/5094043 –

Figure 12. Variation of stomatal (SD) and epidermal cell (ED) density of shade (dark grey box plot) and sun (white box plot) leaves of Liquidambar chinensis. A, Stomatal density, per 1 mm 2. B, Epidermal cell density, per 1 mm 2. A black point in the box indicates the arithmetic mean.


Many factors influence leaf anatomy and morphology in the crown of a tree, particularly those resulting from microclimatic differences between the periphery and the interior of the crown. These influences can be so strong that single species can produce different leaf forms in which shade and sun leaves exhibit consistently distinctive morphological and epidermal character sets.

Here we show, using Liquidambar as a model system, that the principal morphological characters for distinguishing shade and sun leaves in two modern Liquidambar spp. with different lamina types (entire in L. chinensis and lobate in L. formosana) are the leaf lamina length to width ratio, the degree of development of venation networks, tooth size and tooth shape. The main epidermal characters are ordinary cell size and anticlinal wall outlines.

Many fossils, however, are only preserved as impressions and morphological characters alone have been used to distinguish shade and sun leaf morphotypes. To evaluate the utility of our approach, populations of fossil Liquidambar leaves from the Eocene of southern China, preserved only as impressions, were categorized into sun and shade morphotypes.

Recognition that sun and shade leaf morphological diversity exists in fossil populations will enable palaeobotanists to identify more reliably foliar polymorphisms that would otherwise be used to describe, incorrectly, different species.