A new proposal concerning the botanical origin of Baltic amber

Abstract

Baltic amber constitutes the largest known deposit of fossil plant resin and the richest repository of fossil insects of any age. Despite a remarkable legacy of archaeological, geochemical and palaeobiological investigation, the botanical origin of this exceptional resource remains controversial. Here, we use taxonomically explicit applications of solid-state Fourier-transform infrared (FTIR) microspectroscopy, coupled with multivariate clustering and palaeobotanical observations, to propose that conifers of the family Sciadopityaceae, closely allied to the sole extant representative, Sciadopitys verticillata, were involved in the genesis of Baltic amber. The fidelity of FTIR-based chemotaxonomic inferences is upheld by modern-fossil comparisons of resins from additional conifer families and genera (Cupressaceae: Metasequoia; Pinaceae: Pinus and Pseudolarix). Our conclusions challenge hypotheses advocating members of either of the families Araucariaceae or Pinaceae as the primary amber-producing trees and correlate favourably with the progressive demise of subtropical forest biomes from northern Europe as palaeotemperatures cooled following the Eocene climate optimum.

A Diverse Paleobiota in Early Eocene Fushun Amber from China

“…The Fourier transform infrared (FTIR) spectrum of Fushun amber shows characteristics of cupressaceousaraucarian resins [19]. For example, the amplitude of the absorption peak at 1,385 cm 21 is lower than the adjacent peak at 1,460 cm 21 , and the absorption peak at 791 cm 21 is present [19,20] ( Figure S3). The total extracts of Fushun amber were analyzed by gas chromatography-mass spectrometry (GC-MS) ( Figure 2).…”

Characterizing Modern and Fossil Gymnosperm Exudates Using Micro-Fourier Transform Infrared Spectroscopy

“…However, the analysis of S. verticillata resin using methanolytic gas chromatography-mass spectrometry (GC-MS) was not successful in identifying the presence of succinic acid esters in this resin (Wolfe et al 2009). The absorption features traditionally assigned to succinates, therefore, may relate to different and as of yet unidentified compounds that produce similar absorption features.…”

Amber from México: Coahuilite, Simojovelite and Bacalite

“…Later, based on the geological explorations, Langenheim et al [6,8] suggest that the Cretaceous rocks in the vicinities of El Rosario were probably the source of Bacalite. Infrared spectroscopy (IR) is widely used for analytical studies of fossil and recent plant resins [9][10][11][12]. The IR spectrum shows particular fingerprints regions related to identity and botanical affinities of both amber and recent resins.…”