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Dinosaurian soft tissues interpreted as bacterial biofilms.

Kaye TG, Gaugler G, Sawlowicz Z - PLoS ONE (2008)

Bottom Line: Mineralized and non-mineralized coatings were found extensively in the porous trabecular bone of a variety of dinosaur and mammal species across time.Blood cell size iron-oxygen spheres found in the vessels were identified as an oxidized form of formerly pyritic framboids.Our observations appeal to a more conservative explanation for the structures found preserved in fossil bone.

View Article: PubMed Central - PubMed

Affiliation: Department of Paleontology, Burke Museum of Natural History, Seattle, Washington, United States of America. tomkaye@u.washington.edu

ABSTRACT
A scanning electron microscope survey was initiated to determine if the previously reported findings of "dinosaurian soft tissues" could be identified in situ within the bones. The results obtained allowed a reinterpretation of the formation and preservation of several types of these "tissues" and their content. Mineralized and non-mineralized coatings were found extensively in the porous trabecular bone of a variety of dinosaur and mammal species across time. They represent bacterial biofilms common throughout nature. Biofilms form endocasts and once dissolved out of the bone, mimic real blood vessels and osteocytes. Bridged trails observed in biofilms indicate that a previously viscous film was populated with swimming bacteria. Carbon dating of the film points to its relatively modern origin. A comparison of infrared spectra of modern biofilms with modern collagen and fossil bone coatings suggests that modern biofilms share a closer molecular make-up than modern collagen to the coatings from fossil bones. Blood cell size iron-oxygen spheres found in the vessels were identified as an oxidized form of formerly pyritic framboids. Our observations appeal to a more conservative explanation for the structures found preserved in fossil bone.

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Bridging trough structures.(A) Vascular canal showing crack-like morphologies which are actually troughs, suggesting that organisms moved through a viscous medium. (B and C) Close-ups of bridged structures that are inconsistent with inorganic processes. (D) High magnification of additional trough structures showing rounded bottoms and branching morphology. UWBM 89322 Scale bars, 5 µm.
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pone-0002808-g008: Bridging trough structures.(A) Vascular canal showing crack-like morphologies which are actually troughs, suggesting that organisms moved through a viscous medium. (B and C) Close-ups of bridged structures that are inconsistent with inorganic processes. (D) High magnification of additional trough structures showing rounded bottoms and branching morphology. UWBM 89322 Scale bars, 5 µm.

Mentions: Figure 8A shows the concave surface of a vascular canal in trabecular bone. A network of structures, originally overlooked in this survey as cracks, cover the surface. The “cracks”, upon closer inspection, bridge each other in a way that is inconsistent with any inorganic process (Fig. 8, B and C). Closer investigation of these structures reveals a trough rather than a crack (Fig. 8D). This data suggests that these “cracks” are formed by free-swimming microbes or bacteria [5] in a viscous medium–again reinforcing the biofilm hypothesis.


Dinosaurian soft tissues interpreted as bacterial biofilms.

Kaye TG, Gaugler G, Sawlowicz Z - PLoS ONE (2008)

Bridging trough structures.(A) Vascular canal showing crack-like morphologies which are actually troughs, suggesting that organisms moved through a viscous medium. (B and C) Close-ups of bridged structures that are inconsistent with inorganic processes. (D) High magnification of additional trough structures showing rounded bottoms and branching morphology. UWBM 89322 Scale bars, 5 µm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2483347&req=5

pone-0002808-g008: Bridging trough structures.(A) Vascular canal showing crack-like morphologies which are actually troughs, suggesting that organisms moved through a viscous medium. (B and C) Close-ups of bridged structures that are inconsistent with inorganic processes. (D) High magnification of additional trough structures showing rounded bottoms and branching morphology. UWBM 89322 Scale bars, 5 µm.
Mentions: Figure 8A shows the concave surface of a vascular canal in trabecular bone. A network of structures, originally overlooked in this survey as cracks, cover the surface. The “cracks”, upon closer inspection, bridge each other in a way that is inconsistent with any inorganic process (Fig. 8, B and C). Closer investigation of these structures reveals a trough rather than a crack (Fig. 8D). This data suggests that these “cracks” are formed by free-swimming microbes or bacteria [5] in a viscous medium–again reinforcing the biofilm hypothesis.

Bottom Line: Mineralized and non-mineralized coatings were found extensively in the porous trabecular bone of a variety of dinosaur and mammal species across time.Blood cell size iron-oxygen spheres found in the vessels were identified as an oxidized form of formerly pyritic framboids.Our observations appeal to a more conservative explanation for the structures found preserved in fossil bone.

View Article: PubMed Central - PubMed

Affiliation: Department of Paleontology, Burke Museum of Natural History, Seattle, Washington, United States of America. tomkaye@u.washington.edu

ABSTRACT
A scanning electron microscope survey was initiated to determine if the previously reported findings of "dinosaurian soft tissues" could be identified in situ within the bones. The results obtained allowed a reinterpretation of the formation and preservation of several types of these "tissues" and their content. Mineralized and non-mineralized coatings were found extensively in the porous trabecular bone of a variety of dinosaur and mammal species across time. They represent bacterial biofilms common throughout nature. Biofilms form endocasts and once dissolved out of the bone, mimic real blood vessels and osteocytes. Bridged trails observed in biofilms indicate that a previously viscous film was populated with swimming bacteria. Carbon dating of the film points to its relatively modern origin. A comparison of infrared spectra of modern biofilms with modern collagen and fossil bone coatings suggests that modern biofilms share a closer molecular make-up than modern collagen to the coatings from fossil bones. Blood cell size iron-oxygen spheres found in the vessels were identified as an oxidized form of formerly pyritic framboids. Our observations appeal to a more conservative explanation for the structures found preserved in fossil bone.

Show MeSH
Related in: MedlinePlus