The Micro World Embalmed in Amber

by Volker Arnold

How to View Inclusions
 

  • Amber is examined for inclusions mostly by a magnifying glass or a moderately enlarging stereomicroscope. With only a magnifying glass, the smallest inclusions are easily ignored. Therefore an optical microscope with stronger magnification works best. The regular transmitted light found on microscopes has several unfavourable effects. With magnification, a strong reflection at the surface of the inclusions causes them to appear unstructured, black, and not recognizable. Microscopic viewing of inclusions may also require thicker pieces of amber to be reduced by grinding to thin discs.
  • A solution to the lighting problem, when using the microscope, is to utilize lateral light from the glass fiber cold light lamp, combined with microscope objectives that permit a longer distance to the object than normal. It would be best if the longer objectives were equipped with a cover glass correction. The latter enables recognition, in streak-free amber, of objects situated up to 2 mm beyond the amber's surface.
  • A prerequisite for viewing the specimen by the microscope, is to polish the amber as evenly as possible and to place it on the glass slide so that the polished surface is situated at right angles to the microscope axis.

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    Viewing Pollen Grains in Amber
     

  • The following images show pollen grains from long-extinct plants contained in amber that is approximately 45 million years old, Eocene Epoch of the Tertiary Period. Bitterfeld amber may be perhaps somewhat younger than Eocene. The first example shown below is a composite of photos with different sharpness levels. I would appreciate tips and information from pollen analysts or palynologists concerning how to determine what biological information is optimally conserved within pollen grain remains. E-Mail is desired!

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    Riddling Discoveries: Fungi? Tiny amimals? Seed grains of Orchideae? I welcome comments regarding this image and others.
     


    1 Pine pollen grains, 65 and about 50 µm long, Baltic amber (very frequent).
    2 - 3 Three colpate long-axed pollen grains. Number 2 is oak-like, 47 µm long, in Bitterfeld amber. Number 3 is spinulose, ilex-like, 38 µm long, in Baltic amber.
    4 Ephedroid (joint pine, Gnetaceae) pollen grains, about 30 µm long, in Baltic amber. This image can be seen with better resolution!

    Pollen in amber 1, low resolution

    This image can be seen with better resolution!
    5, 7, 8 Various angiosperm pollen grains. Images 7 and 8 are in the same piece of Bitterfeld amber as number 2. Sizes: larger long-axed grain in number 5 is around 30 µm, and 50 µm in numbers 7 and 8.
    6 Monocolpate grain, alga zygospore or large liliaceae pollen grain, around 80 µm long, in Baltic amber.
    9 - 10 Monocolpate pollen grains, probably of monocotyle angiosperm plants (e.g. palms). Number 9 is Bitterfeld amber (about 40 µm), while number 10 is Baltic amber (about 18 µm).
    11 Group of short-axed angiosperm pollen grains, each around 50 µm, in Baltic amber.
    12 Tetrad, probably heath plants (Ericaceae), about 40 µm. Most tetrads in amber are strongly infolded.
    13 Indefinite short-axed spherical angiosperm pollen grain with blisters at the germinal pores, about 65 µm, in Bitterfeld amber.
    14 Tilioid (lime tree-like) short-axed pollen grain, 47 µm, infolded in the center, in Baltic amber.
    15 Short-axed pollen grain with three large germ blisters, 51 µm, in Bitterfeld amber.
    16 Similar pollen grain as in number 15, 55 µm. "Shrinking cores" can be seen in this Bitterfeld amber specimen, resulting from penetration of immersion oil.
    17 Spherical pollen grain (Milfordia?) covered with regular depressions, 32 µm, Bitterfeld amber.
    See the following picture at a better resolution!

    Pollen in amber 2, low resolution

    18 Two pollen grains from the same piece of Bitterfeld amber, containing pressed spherical short-axed grains with 4 and 5 equatorial pores, about 30 µm.
    19 Three porate short-axed pollen grain, Normapolles - cf. Nudopollis?, 35 µm, in Baltic amber.
    20 Three porate short-axed pollen grain, 30 µm, in Bitterfeld amber.
    21 Pressed spherical pollen grains with 7 resp. 8 equatorial pores, ulmus-like, 38 µm, in Baltic amber.
    22 Three porate short-axed pollen grain, Normapolles - cf. Basopollis?, about 40 µm, in Baltic amber.
    23 Loranthaceae (mistletoe plants) pollen grains (cf. Gothanipollis), slim form, 30 µm, in Baltic amber (same amber specimen as number 6).
    24 Loranthaceae pollen grains, more compact form, around 40 µm, in Bitterfeld amber. This image is shown with better resolution!
    On the Internet you can find a stamen with pollen in Dominican amber (image courtesy of J. Santiago-Blay and G. Poinar).

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