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Author Topic:   Blood in dino bones
gnojek
Inactive Member


Message 26 of 138 (194496)
03-25-2005 5:51 PM
Reply to: Message 7 by Sylas
03-25-2005 2:34 AM


Re: Read the article more closely...
Thanks for the citation.
Someone else had a link to a page that had some of the images from the paper, but I'll try to post all of them here. Some of the ones not posted on that website are pretty compelling even to a layman. Some of the images jump right out at you screaming "I'm a cell!"
Comparison of T. rex objects (left) with ostrich cells (right).
Caption.
Fig. 4. Cellular features associated with T. rex and ostrich tissues. (A) Fragment of demineralized cortical bone from T. rex, showing parallel-oriented fibers and cell-like microstructures among the fibers. The inset is a higher magnification of one of the microstructures seen embedded in the fibrous material. (B) Demineralized and stained (3) ostrich cortical bone, showing fibrillar, parallel-oriented collagen matrix with osteocytes embedded among the fibers. The inset shows a higher magnification of one of the osteocytes. Both inset views show elongate bodies with multiple projections arising from the external surface consistent with filipodia. (C) Isolated microstructure from T. rex after fixation. In addition to the multiple filipodial-like projections, internal contents can be seen. The inset shows a second structure with long filipodia and an internal transparent nucleus-like structure. (D) Fixed ostrich osteocyte; inset, ostrich osteocyte fixed and stained for better visualization. Internal contents are discernible, and filipodia can be seen extending in multiple planes from the cell surface. (E and F) SEM images of aldehyde-fixed (3) microstructures isolated from T. rex cortical bone tissues. Scale bars in (A) and (B), 50 m; in (C) and (D), 20 m; in (E), 10 m; in (F), 1 m.
Caption.Fig. 3. SEM images of aldehyde-fixed vessels. (A) Isolated vessel from T. rex. (B) Vesselisolated from extant ostrich after demineralization and collagenase digestion (3). (C) Vesselfrom T. rex, showing internal contents and hollow character. (D) Exploded T. rex vessel showing small round microstructures partially embedded in internal vessel walls. (E) Highermagnification of a portion of T. rex vessel wall, showing hypothesized endothelial nuclei (EN). (F) Similar structures visible on fixed ostrich vessel. Striations are seen in both (E) and (F) that may represent endothelial cell junctions or alternatively may be artifacts of the fixation/dehydration process. Scale bars in (A) and (B), 40 m; in (C) and (D), 10 m; in (E) and (F), 1 m.
Caption.Fig. 2. Demineralization of cortical bone reveals the presence of soft-tissue structures. (A) Partial demineralization of a fragment of T. rex cortical bone shows an emerging network of vascular canals, some of which are bifurcated (arrows). All are aligned in parallel, consistent with Haversian canals in cortical bone. Small fenestrae (marked F) may indicate invaginations for communicating Volkmann's canals. (B) A second fragment of T. rex cortical bone illustrates transparent vessels (arrows) arising from bone matrix in solution. (C) Complete demineralization reveals transparent flexible vessels in what remains of the cortical bone matrix, represented by a brown amorphous substance (marked M). (D) Ostrich vessel after demineralization of cortical bone and subsequent digestion of fibrous collagenous matrix. Transparent vessels branch and remain associated with small regions of undigested bone matrix, seen here as amorphous, white fibrous material (marked M). Scale bars in (A) to (D), 0.5 mm. (E) Higher magnification of dinosaur vessels shows branching pattern (arrows) and internal contents. Vascular structure is not consistent with fungal hyphae (no septae, and branching pattern is not consistent with fungal morphology) or plant (no cell walls visible, and again branching pattern is not consistent). Round red microstructures within the vessels are clearly visible. (F) T. rex vessel fragment, containing microstructures consistent in size and shape with those seen in the ostrich vessel in (H). (G) Second fragment of dinosaur vessel. Air/fluid interfaces, represented by dark menisci, illustrate the hollow nature of vessels. Microstructure is visible within the vessel. (H) Ostrich vessel digested from demineralized cortical bone. Red blood cells can be seen inside the branching vessel. (I) T. rex vessel fragment showing detail of branching pattern and structures morphologically consistent with endothelial cell nuclei (arrows) in vessel wall. (J) Ostrich blood vessel liberated from demineralized bone after treatment with collagenase shows branching pattern and clearly visible endothelial nuclei. Scale bars in (E) to (J), 50 m. (F), (I), and (J) were subjected to aldehyde fixation (3). The remaining vessels are unfixed.
Caption.Fig. 1. Demineralized fragments of endosteally derived tissues lining the marrow cavity of the T. rex femur. (A) The demineralized fragment is flexible and resilient and, when stretched (arrow), returns to its original shape. (B) Demineralized bone in (A) after air drying. The overall structural and functional characteristics remain after dehydration. (C) Regions of demineralized bone show fibrous character (arrows). Scale bars, 0.5 mm.
The suplemental info is in PDF format, but it has some really nice images also, as well as more supporting data.
edit: pdf's of The Article and Supplemental
This message has been edited by gnojek, 03-25-2005 06:06 PM

This message is a reply to:
 Message 7 by Sylas, posted 03-25-2005 2:34 AM Sylas has not replied

  
gnojek
Inactive Member


Message 27 of 138 (194502)
03-25-2005 6:20 PM


Sorry for multiple posts, but reading the supplemental answers and earlier issue raised regarding whether this is the first time or only time this sort of thing has been seen.
Quoting pg. 6 - "3. Osteocytes. Preservation of small microstructures consistent with osteocytes have been recovered from three dinosaurs in addition to MOR 1125."
Oh, and someone commented on "matrix" sounding unreal, whatever that means. People refer to a material in which other materials are merely embedded as a matrix. If you found a piece of dirty sand and you identified some inclusions as being iron or something, you'd say that it was iron particles in a silica matrix. Or the little pieces of glitter in a ball of toy slime are in the matrix of the slime.
Figure S2 is blowing my mind, especially the fact that it is taking up common stains normally used in "fresh" samples.

  
gnojek
Inactive Member


Message 55 of 138 (195207)
03-29-2005 1:23 PM
Reply to: Message 40 by simple
03-26-2005 12:39 PM


Re: stretching the evidence
You did notice that one of your quotes speaks against your case.
quote:
"It has always been thought that cells couldn't be preserved, but there really wasn't any evidence to back up those ideas, other than no one having found cellular preservation before."
Montana T. Rex Yields Next Big Discovery in Dinosaur Paleontology
So you realize that what this quote says is that previous assumptions made about cell preservation may not be correct in light of new evidence.

This message is a reply to:
 Message 40 by simple, posted 03-26-2005 12:39 PM simple has replied

Replies to this message:
 Message 56 by simple, posted 03-29-2005 9:33 PM gnojek has replied

  
gnojek
Inactive Member


Message 58 of 138 (195455)
03-30-2005 1:23 PM
Reply to: Message 56 by simple
03-29-2005 9:33 PM


Re: stretching the evidence
There are far fewer assumptions being made about radioactive decay since we can observe it happening.
The reason people have to make assumptions about the preservation of organic material over millions of years is because there is so little real data on this type of thing. It's difficult to know what the conditions inside the T. rex bone was for 70 million years, much less being able to simulate it.
If they find viable DNA, I would be very surprised, but it's not outside of the realm of possibility. I would put money on them not being able to pull even a preliminary Jurassic Park type thing, as in I seriously doubt they'll be able to sequence T. rex's genome or something like that. The DNA is likely there in small fragments if it is there at all anymore.

This message is a reply to:
 Message 56 by simple, posted 03-29-2005 9:33 PM simple has replied

Replies to this message:
 Message 60 by simple, posted 03-31-2005 2:26 AM gnojek has not replied

  
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