Abstract
The Eocene (∼48 Ma) Messel Pit in Germany is a UNESCO World Heritage Site
because of its exceptionally preserved fossils, including vertebrates, invertebrates,
and plants. Messel fossil vertebrates are typically characterized by their articulated
state, and in some cases the skin, hair, feathers, scales and stomach contents are
also preserved. Despite the exceptional macroscopic preservation of Messel fossil
vertebrates, the microstructural aspect of these fossils has been poorly explored. In
particular, soft tissue structures such as hair or feathers have not been chemically
analyzed, nor have bone microstructures. I report here the preservation and recovery
of osteocyte-like and blood vessel-like microstructures from the bone of Messel Pit
specimens, including the turtles Allaeochelys crassesculpta and Neochelys franzeni,
the crocodile Diplocynodon darwini, and the pangolin Eomanis krebsi. I used a
Field Emission Scanning Electron Microscope (FESEM) and a Phenom ProX
desktop scanning electron microscope (LOT-QuantumDesign) equipped with a
thermionic CeB6 source and a high sensitivity multi-mode backscatter electron (BSE)
for microscopical and elemental characterization of these bone microstructures.
Osteocyte-like and blood vessel-like microstructures are constituted by a thin layer
(∼50 nm thickness), external and internal mottled texture with slightly marked
striations. Circular to linear marks are common on the external surface of the
osteocyte-like microstructures and are interpreted as microbial troughs. Iron (Fe)
is the most abundant element found in the osteocyte-like and blood vessel-like
microstructures, but not in the bone matrix or collagen fibril-like microstructures.
The occurrence of well-preserved soft-tissue elements (at least their physical form)
establishes a promising background for future studies on preservation of biomolecules
(proteins or DNA) in Messel Pit fossils.
because of its exceptionally preserved fossils, including vertebrates, invertebrates,
and plants. Messel fossil vertebrates are typically characterized by their articulated
state, and in some cases the skin, hair, feathers, scales and stomach contents are
also preserved. Despite the exceptional macroscopic preservation of Messel fossil
vertebrates, the microstructural aspect of these fossils has been poorly explored. In
particular, soft tissue structures such as hair or feathers have not been chemically
analyzed, nor have bone microstructures. I report here the preservation and recovery
of osteocyte-like and blood vessel-like microstructures from the bone of Messel Pit
specimens, including the turtles Allaeochelys crassesculpta and Neochelys franzeni,
the crocodile Diplocynodon darwini, and the pangolin Eomanis krebsi. I used a
Field Emission Scanning Electron Microscope (FESEM) and a Phenom ProX
desktop scanning electron microscope (LOT-QuantumDesign) equipped with a
thermionic CeB6 source and a high sensitivity multi-mode backscatter electron (BSE)
for microscopical and elemental characterization of these bone microstructures.
Osteocyte-like and blood vessel-like microstructures are constituted by a thin layer
(∼50 nm thickness), external and internal mottled texture with slightly marked
striations. Circular to linear marks are common on the external surface of the
osteocyte-like microstructures and are interpreted as microbial troughs. Iron (Fe)
is the most abundant element found in the osteocyte-like and blood vessel-like
microstructures, but not in the bone matrix or collagen fibril-like microstructures.
The occurrence of well-preserved soft-tissue elements (at least their physical form)
establishes a promising background for future studies on preservation of biomolecules
(proteins or DNA) in Messel Pit fossils.
| Original language | Spanish (Colombia) |
|---|---|
| Pages (from-to) | e1618 |
| Number of pages | 17 |
| Journal | PeerJ |
| Volume | 4 |
| DOIs | |
| State | Published - Jan 21 2016 |