An unusual megaspore of uncertain systematic affinity from Lower Cretaceous deposits in south-east England and its biostratigraphic and palaeoenvironmental significance

Abstract

Batten, D. J. (2009). An unusual megaspore of uncertain systematic affinity from Lower Cretaceous deposits in south-east England and its biostratigraphic and palaeoenvironmental significance. Grana, 48(4), 270-280.An unusual megaspore has been recorded from beds within the Weald Clay Group of south-east England. Described as Clockhousea capelensis gen. et sp. nov., it is characterised by having a thick outer layer of exine consisting of closely packed columnar to clavate elements with constricted bases attached to a perforated inner layer and a sculpture that ranges from having the appearance of a negative reticulum through closely spaced verrucae to a mixture of verrucate and essentially baculate elements, all of which are surface manifestations and extensions of the underlying structure. These characters do not readily indicate a systematic relationship with any known heterosporous plant genus or family. The localised occurrence and relative abundance of the spores in a few beds suggest that some of the parent plants grew close to water bodies where they were deposited and preserved. Their recovery from sediments of late Hauterivian-early Barremian age indicates that the species has potential as a biostratigraphic marker in the upper Wealden succession of southern England and perhaps elsewhere.Peer reviewe

A new afrograptid (Diplostraca: Estheriellina) from the Lower Cretaceous of southern England

“…Specimens in this study were collected by Edmund A. Jarzembowski from the Lower Cretaceous Upper Weald Clay Formation (lower Barremian, see detailed information in Batten, 2009) in the northeastern face of the pit at the Smokejacks Brickworks (Ewhurst Works), Ockley Village, Surrey County, southern England (Fig. 1).…”

“…The fossils are preserved in sideritic mudstone from the upper insect bed in the mudstone interval below British Geological Survey Bed 5c which is present at the top of this pit and suggests an early Barremian age for this site (cf. Batten, 2009;Fig. 2, and see detailed lithostratigraphical logs in Ross and Cook, 1995).…”

Plant mobility in the Mesozoic: Disseminule dispersal strategies of Chinese and Australian Middle Jurassic to Early Cretaceous plants

“…7H-J), but no seeds have been associated with these fossils and they may alternatively represent dehisced bryophyte sporangia or even some vegetative organ (Drinnan and Chambers, 1986). Dispersed megaspores referable to Arcellites have elaborate proximal acrolamellae that may represent an adaptation to flotation and were probably produced by semi-aquatic ferns (Batten, 2009). Their occurrences in roughly coeval strata in northeastern China and southeastern Australia (Li and Batten, 1986;Tosolini et al, 2002) are among the earliest examples of this group and suggest that heterosporous ferns rapidly dispersed throughout the world in the Early Cretaceous contemporaneously with angiosperms.…”