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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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Iron oxide framboids.An iron oxide framboid cluster in dinosaur trabecular bone found commonly throughout time and taxa. At approximately 10 microns in diameter they are closely matched in size to red blood cells and typical pyrite framboids. UWBM 89327 Scale bar, 3 µm.
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pone-0002808-g003: Iron oxide framboids.An iron oxide framboid cluster in dinosaur trabecular bone found commonly throughout time and taxa. At approximately 10 microns in diameter they are closely matched in size to red blood cells and typical pyrite framboids. UWBM 89327 Scale bar, 3 µm.

Mentions: The hollow morphology of the tyrannosaur femur supported the general idea that an exceptionally well-preserved bone may act as a containment vessel for biomolecules. To test this concept, a perfectly preserved turtle phalange showing no cracks or deformities (Fig. 2) was first selected for SEM examination. The specimen was pressure fractured and directly examined uncoated in the SEM. A cluster of spheres approximately 10 microns in diameter, similar to Fig. 3, was discovered almost immediately. Subsequent EDS showed an iron-oxygen signature. Continuing SEM surveys of multiple specimens from the Lance, Hell Creek, Chadron and Pierre Shale formations all showed similar iron-oxygen spheres ranging in size from 5–29 microns. Examination of demineralized specimens under the light microscope displayed small red spheres clustered in the tubular structures (Fig. 4A). Discovery of these spheres in an ammonite suture indicated they had no relationship to iron derived from blood. These spheres were identified as framboids which are seen world wide in black smokers, algal mats and are commonly found in sediments [4].


Dinosaurian soft tissues interpreted as bacterial biofilms.

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

Iron oxide framboids.An iron oxide framboid cluster in dinosaur trabecular bone found commonly throughout time and taxa. At approximately 10 microns in diameter they are closely matched in size to red blood cells and typical pyrite framboids. UWBM 89327 Scale bar, 3 µm.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0002808-g003: Iron oxide framboids.An iron oxide framboid cluster in dinosaur trabecular bone found commonly throughout time and taxa. At approximately 10 microns in diameter they are closely matched in size to red blood cells and typical pyrite framboids. UWBM 89327 Scale bar, 3 µm.
Mentions: The hollow morphology of the tyrannosaur femur supported the general idea that an exceptionally well-preserved bone may act as a containment vessel for biomolecules. To test this concept, a perfectly preserved turtle phalange showing no cracks or deformities (Fig. 2) was first selected for SEM examination. The specimen was pressure fractured and directly examined uncoated in the SEM. A cluster of spheres approximately 10 microns in diameter, similar to Fig. 3, was discovered almost immediately. Subsequent EDS showed an iron-oxygen signature. Continuing SEM surveys of multiple specimens from the Lance, Hell Creek, Chadron and Pierre Shale formations all showed similar iron-oxygen spheres ranging in size from 5–29 microns. Examination of demineralized specimens under the light microscope displayed small red spheres clustered in the tubular structures (Fig. 4A). Discovery of these spheres in an ammonite suture indicated they had no relationship to iron derived from blood. These spheres were identified as framboids which are seen world wide in black smokers, algal mats and are commonly found in sediments [4].

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