has been well known for its inclusions for centuries, and speculation on its
origins as a tree resin dates certainly as far back as Pliny the Elder in 49 AD
and perhaps earlier (Healy 2004, Clark 2010). Many have suggested that the
origin of the resin may have been a variety of pine tree (Healy 2004, Clark
2010) and some have suggested the name Pinites succinifer (Göppert 1846).
Despite the similarity of the resin to the conifer families Araucariaceae and
Pinaceae, it may be that the tree that produced the resin was more closely
related to the Sciadopityaceae which is now represented by a single species
Sciadopitys verticillata (Japanese Umbrella-pine) (Wolfe et al. 2009).
This study was
unable to obtain the depth penetration, nor the differential fluorescence
between the insect and the amber resin, necessary to obtain insect images
similar in quality to those obtained by Böker & Brocksch (2002). Both the
insects and the amber fluoresce in the ultra-violet part of the spectrum making
it difficult to distinguish between them.
known to contain (blue-green) autofluorescent flavanoids. The samples of amber
have strong autofluorescence in the UV range which enables discrimination of
amber from the embedded trichome. Our initial observations of a strong
autofluorescence in the far red spectrum suggest the presence of an alternative
compound or a modified form of flavonoid present within amber-included trichomes.
Alternatively, the trichomes may have been transformed and/or chemically altered
over time. Whilst this certainly warrants further study, the main aim of this
project was to examine the structure of the trichomes and assess the usefulness
trichomes examined in this study differ from the trichomes from Baltic amber and
may belong to the Family Euphorbiaceae.
Baltic trichome that was chosen for the study has a stellate form with seventeen
radii (figures 1, 2; animation 1). Overlapping radii give the appearance of
bifurcation, but when viewed in 3D, it is evident that they are separate radii.
The trichome appears to have two stellate clusters superimposed on each other (geminate).
One of the radii is longer than the others perhaps representing a stalk. The
trichome here is consistent with the structure of trichomes of the Fagaceae, or
oak family (Hong-Ping et al. 1990, Nixon 2002, González-Villarreal 2003a,
CLSM may be
further developed to help with producing 3D images of inclusions in amber.
Although the technique seems to be limited by the size of the inclusions and the
depth at which the inclusion appears, Böker & Brocksch (2002) have shown that it
is possible to produce high definition 3D images of larger insect inclusions.
The equipment at the University of Glasgow is not optimised for such analyses,
but has been useful in producing 3D images of very small trichome inclusions.
Further refinement of this technique and equipment may allow useful systematic
study of inclusions in amber by providing very high resolution 3D imagery of the
anatomy of inclusions.
amber using computed tomography and phase contrast X-ray synchrotron
microradiography has provided the opportunity for 3D analysis of larger fossil
inclusions (Polcyn et al. 2002, Lak et al. 2008, 2009). This technique provides
very high resolution 3D images of the fossil contents of the amber and has been
particularly useful in examining opaque amber (Lak et al. 2008). The long term
effects of exposure to a high energy monochromatic beam on amber are unknown,
but the benefit of being able to visualise the contents of opaque amber is great.
limited usefulness in the analysis of amber inclusions due to the lack of
penetration and the reliance on the differential fluorescence between the
inclusions and the amber. Nevertheless, CLSM has potential value in recognising
different fluorescing properties perhaps providing an indication of different
compositional or structural architecture.