Leaf architecture and ecophysiology of an early basal eudicot from the Early Cretaceous of Spain

Abstract

Iterophyllum lobatum gen. et sp. nov. is reported from the late Barremian lithographic limestones of Las Hoyas, Spain. It consists of a simple, petiolate leaf, with a pinnately lobed lamina. The dentate thickened margin bears chloranthoid-like glands at lobe apices and sinuses. The venation is pinnate and craspedodromous, with three discernible vein orders. Based on the low regularity of vein course and angles and the low leaf rank, such a venation pattern may represent an early evolved leaf archetype in early basal eudicots. An acropetal leaf development mode in I. lobatum is similar to that in several living Papaveraceae. The leaf architecture and ecophysiology, particularly the vein widths and the glands, indicate that I. lobatum leaves were aerial. The plant grew close to water in the wetland terrestrial ecosystem of Las Hoyas. Iterophyllum lobatum might have been an opportunist species in early ecological succession stages after wildfires.

Fossil evidence for a herbaceous diversification of early eudicot angiosperms during the Early Cretaceous

“…The slender and flexuous stems of Fairlingtonia show that it was herbaceous ( figures 3b and 4a,b). The presence of lobed leaves with glandular teeth and short marginal petioles, rather than cordate, peltate or filiform leaves with long petioles and entire margins, support the conclusion that Fairlingtonia was a terrestrial herb rather than an aquatic one [39,40]. Furthermore, the small size, adventitious roots (figure 4a) and abundance of resting buds (figure 3a) suggests a potential for vigorous opportunistic growth, typical of creeping or scrambling herbs adapted to colonizing freshly disturbed substrates [41][42][43].…”

Scaling of phloem hydraulic resistance in stems and leaves of the understory angiosperm shrub Illicium parviflorum

“…These lineages, particularly Austrobaileyales and the monotypic Amborella , are excellent candidates to understand the physiological properties of arborescent plants that live in conditions with limited light. Most studies of extant members from this grade focused on the xylem (Feild et al., , ; Feild and Arens, , ; Barral et al., ). Anatomically, these lineages are characterized by a small vessel lumen fraction in the stems (Bailey and Nast, ; Carlquist, ; Carlquist and Schneider, ), leaves with thick cuticles and large stomata, as well as irregular leaf venation (Hickey and Doyle, ; Upchurch et al., ; Carpenter, ; Coiffard et al., ).…”

Early Cretaceous angiosperm leaves from the Dakota Formation, Hoisington III locality, Kansas, USA

“…Many recent discoveries of the Early Cretaceous fossil leaves with similar tooth pattern have been proposed to be related to the Eudicots. For example, Iterophyllum lobatum Barral et al (Ranucuales;Barral et al, 2013) is a fossil species based on leaves from the late Barremian of Las Hoyas, Spain. The simple leaf is petiolate and pinnately lobed with chloranthoid-like glands at the lobe apices and the sinuses.…”