Production and preservation of resins – past and present

Abstract

Amber is fossilised plant resin. It can be used to provide insights into the terrestrial conditions at the time the original resin was exuded. Amber research thus can inform many aspects of palaeontology, from the recovery and description of enclosed fossil organisms (biological inclusions) to attempts at reconstruction of past climates and environments. Here we focus on the resin itself, the conditions under which it may have been exuded, and its potential path to fossilisation, rather than on enclosed fossils. It is noteworthy that not all plants produce resin, and that not all resins can (nor do) become amber. Given the recent upsurge in the number of amber deposits described, it is time to re-examine ambers from a botanical perspective. Here we summarise the state of knowledge about resin production in modern ecosystems, and review the biological and ecological aspects of resin production in plants. We also present new observations on conifer-derived resin exudation, with a particular focus on araucarian conifer trees. We suggest that besides disease, insect attacks and traumatic wounding from fires and storms, other factors such as tree architecture and local soil conditions are significant in creating and preserving resin outpourings. We also examine the transformation of resin into amber (maturation), focusing on geological aspects of amber deposit formation and preservation. We present new evidence that expands previous understanding of amber deposit formation. Specific geological conditions such as anoxic burial are essential in the creation of amber from resin deposits. We show that in the past, the production of large amounts of resin could have been linked to global climate changes and environmental disruption. We then highlight where the gaps in our knowledge still remain and potential future research directions.

Morphological Convergence in Forest Microfungi Provides a Proxy for Paleogene Forest Structure

“…and Bitterfeld amber. Suggested source plants of succinite include representatives of the Araucariaceae, Cupressaceae, Pinaceae, and Sciadopityaceae (Langenheim, 2003;Yamamoto et al, 2006;Wolfe et al, 2009;Seyfullah et al, 2018).…”

Phytophthora agathidicida: research progress, cultural perspectives and knowledge gaps in the control and management of kauri dieback in New Zealand

“…The symptoms of kauri dieback are excessive resin production (i.e. gummosis, hyper‐resinosis; Seyfullah et al , ) at the collar and lower trunk region of the tree, and crown decline, usually leading to tree mortality (Fig. a,b).…”

Selaginella was hyperdiverse already in the Cretaceous

“…Amber does not occur continuously in Earth history (Seyfullah et al, 2018), and only a few Cretaceous and Cenozoic ambers have preserved plant remains in larger numbers. Kachin amber, the older variety of the more widely known Burmese amber, originates from the Albian-Cenomanian (c. 100 million years old (Ma)) of Myanmar (for additional information on provenance and age, refer to Supporting Information Notes S1), and presently represents the most important source of three-dimensionally preserved younger Mesozoic terrestrial organisms (plants, animals and microorganisms).…”