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Soft-Tissue Vessels and Cellular Preservation in Tyrannosaurus rex

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Soft tissues are preserved within hindlimb elements of Tyrannosaurus rex (Museum of the Rockies specimen 1125). Removal of the mineral phase reveals transparent, flexible, hollow blood vessels containing small round microstructures that can be expressed from the vessels into solution. Some regions of the demineralized bone matrix are highly fibrous, and the matrix possesses elasticity and resilience. Three populations of microstructures have cell-like morphology. Thus, some dinosaurian soft tissues may retain some of their original flexibility, elasticity, and resilience.
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DOI: 10.1126/science.1108397
, 1952 (2005); 307Science
et al.Mary H. Schweitzer,
Tyrannosaurus rex
Soft-Tissue Vessels and Cellular Preservation in
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Anomalies in the strength of the Hadley cells
are inversely correlated with anomalies in the
strength of the Walker oscillation (18, 31):
Weakened Hadley cells correlate with epi-
sodes of La NiDa and strong Walker circula-
tion. Second, the stronger oceanic heat flux to
the high latitudes is consistent with enhanced
Ekman flow of warm water poleward as a re-
sult of increased Walker circulation. The con-
straint of a balanced heat budget during the
Pliocene implies that this increased heat loss
at high latitudes through vigorous deep-ocean
thermohaline circulation is accompanied by a
shoaling of the tropical thermocline (32). Most
oceanic heat gain occurs in low and mid-
latitude upwelling zones and is large (small)
when the thermocline is shallow (deep). Dur-
ing the Pliocene, the deeper thermocline in the
WEP argues that thermocline tilt must be great-
er to allow shoaling of the EEP thermocline.
Our data rebut the hypothesis that Bhothouse[
climates collapse onto an El NiDo–like state,
in agreement with Eocene hothouse studies
(33), and indicate that the tropical upper-ocean
structure during the warm Pliocene was indic-
ative of a La NiDa–like state consistent with
the dynamical Bocean thermostat.[ Twentieth-
century global warming has also resulted in a
stronger east-west SST gradient (34)ona
contrastingly rapid time scale. Both of these
scenarios, reflecting mean and transient Pacif-
ic states, respectively, support the role of the
Bjerknes feedback inhibiting an El NiDo posi-
tive feedback to global warming. Interestingly,
during the Pliocene the increase in east-west
SST gradient is due to eastern cooling, whereas
during the 20th century it is due to WEP warm-
ing. In the near future, if the warming of the
WEP warm pool reaches a limit without a
compensating cooling in the east (afforded
by the EUC during the Pliocene), could the
Bjerknes feedback be reversed to incite accel-
erated warmth of an El NiDo–like state?
References and Notes
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to the Ocean Drilling Program for providing samples
and to the Natural Environment Research Council for
providing financial support.
Supporting Online Material
www.sciencemag.org/cgi/content/full/307/5717/1948/
DC1
Materials and Methods
References
30 August 2004; accepted 24 January 2005
10.1126/science.1104666
Soft-Tissue Vessels and Cellular
Preservation in Tyrannosaurus rex
Mary H. Schweitzer,
1,2,3
*
Jennifer L. Wittmeyer,
1
John R. Horner,
3
Jan K. Toporski
4
.
Soft tissues are preserved within hindlimb elements of Tyrannosaurus rex
(Museum of the Rockies specimen 1125). Removal of the mineral phase reveals
transparent, flexible, hollow blood vessels containing small round micro-
structures that can be expressed from the vessels into solution. Some regions
of the demineralized bone matrix are highly fibrous, and the matrix possesses
elasticity and resilience. Three populations of microstructures have cell-like
morphology. Thus, some dinosaurian soft tissues may retain some of their
original flexibility, elasticity, and resilience.
A newly discovered specimen of Tyranno-
saurus rex EMuseum of the Rockies (MOR)
specimen 1125^ was found at the base of the
Hell Creek Formation, 8 m above the Fox
Hills Sandstone, as an association of disartic-
ulated elements. The specimen was incorpo-
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rated within a soft, well-sorted sandstone that
was interpreted as estuarine in origin. Al-
though some bones are slightly deformed or
crushed, preservation is excellent. MOR
1125 represents a relatively small individual
of T. rex, with a femoral length of 107 cm, as
compared to the Field Museum (Chicago)
specimen (FMNH PR2081) that has a fem-
oral length of approximately 131 cm. On the
basis of calculated lines of arrested growth
(LAG), we estimated that this animal was 18 T
2 years old at death (1).
No preservatives were applied to interior
fragments of the femur of MOR 1125 during
preparation, and these fragments were reserved
for chemical analyses. In addition to the dense
compact bone typical of theropods, this spec-
imen contained regions of unusual bone tissue
on the endosteal surface (2). Cortical and end-
osteal bone tissues were demineralized (3), and
Fig. 1. Demineralized fragments of end-
osteally derived tissues lining the mar-
row cavity of the T. rex femur. (A) The
demineralized fragment is flexible and
resilient and, when stretched (arrow),
returns to its original shape. (B)De-
mineralized bone in (A) after air dry-
ing. The overall structural and functional
characteristics remain after dehydration.
(C) Regions of demineralized bone show
fibrous character (arrows). Scale bars,
0.5 mm.
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 sub-
stance (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 mm. (F), (I), and (J) were
subjected to aldehyde fixation (3). The remaining vessels are unfixed.
1
Department of Marine, Earth, Atmospheric Sciences,
North Carolina State University, Raleigh, NC 27695,
USA.
2
North Carolina State Museum of Natural
Sciences, Raleigh, NC 27601, USA.
3
Museum of the
Rockies, Montana State University, Bozeman, MT
59717, USA.
4
Carnegie Institution of Washington,
Geophysical Laboratory, 5251 Broad Branch Road
N.W., Washington, DC 20018, USA.
*To whom correspondence should be addressed.
E-mail: schweitzer@ncsu.edu
.Present address: Department of Geosciences, Christian-
Albrechts University Kiel, Olshausenstrasse 40, 24098
Kiel, Germany.
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after 7 days, several fragments of the lining
tissue exhibited unusual characteristics not
normally observed in fossil bone. Removal of
the mineral phase left a flexible vascular tissue
that demonstrated great elasticity and resil-
ience upon manipulation. In some cases, re-
peated stretching was possible (Fig. 1A, arrow),
and small pieces of this demineralized bone
tissue could undergo repeated dehydration-
rehydration cycles (Fig. 1B) and still retain
this elastic character. Demineralization also
revealed that some regions of the bone were
highly fibrous (Fig. 1C, arrows).
Partial demineralization of the cortical bone
revealed parallel-oriented vascular canals that
were seen to bifurcate in some areas (Fig. 2A,
arrows). Occasional fenestrae (marked F)
were observed on the surface of the vascular
canals, possibly correlating with communicat-
ing Volkmann_s canals. Complete demin-
eralization of the cortical bone released thin
and transparent soft-tissue vessels from some
regions of the matrix (Fig. 2, B and C), which
floated freely in the demineralizing solution.
Vessels similar in diameter and texture were
recovered from extant ostrich bone, when de-
mineralization was followed by digestion with
collagenase enzyme (3) to remove densely fi-
brous collagen matrix (Fig. 2D). In both dino-
saur (Fig. 2C) and ostrich (Fig. 2D), remnants
of the original organic matrix in which the
vessels were embedded can still be visualized
under transmitted light microscopy. These
vessels are flexible, pliable, and translucent
(Fig. 2E). The vessels branch in a pattern
consistent with extant vessels, and many bi-
furcation points are visible (Fig. 2E, arrows).
Many of the dinosaur vessels contain small
round microstructures that vary from deep red
to dark brown (Fig. 2, F and G). The vessels
and contents are similar in all respects to
blood vessels recovered from extant ostrich
bone (Fig. 2H). Aldehyde-fixed (3) dinosaur
vessels (Fig. 2I) are virtually identical in over-
all morphology to similarly prepared ostrich
vessels (Fig. 2J), and structures consistent with
remnants of nuclei from the original endothe-
lial cells are visible on the exterior of both
dinosaur and ostrich specimens (Fig. 2, I and
J, arrows).
Under scanning electron microscopy (SEM)
(Fig. 3), features seen on the external surface of
dinosaurian vessels are virtually indistinguish-
able from those seen in similarly prepared
extant ostrich vessels (Fig. 3, B and F), sug-
gesting a common origin. These features
include surface striations that may be consistent
with endothelial cell junctions, or alternatively
may be artifacts of fixation and/or dehydration.
In addition, small round to oval features dot the
surface of both dinosaur and ostrich vessels,
which may be consistent with endothelial cell
nuclei (Fig. 3, E and F, arrows).
Finally, in those regions of the bone where
fibrillar matrix predominated in the deminer-
alized tissues, elongate microstructures could
be visualized among the fibers (Fig. 4A,
inset). These microstructures contain multiple
projections on the external surface and are
virtually identical in size, location, and overall
morphology to osteocytes seen among colla-
Fig. 3. SEM images of
aldehyde-fixed vessels.
(A) Isolated vessel from
T. rex.(B)Vesselisolated
from extant ostrich af-
ter demineralization
and collagenase diges-
tion (3). (C)Vesselfrom
T. rex,showinginternal
contents and hollow
character. (D)Exploded
T. rex vessel showing
small round microstruc-
tures partially embed-
ded in internal vessel
walls. (E)Highermagnifi-
cation of a portion of T.
rex vessel wall, showing
hypothesized endotheli-
al nuclei (EN). (F)Sim-
ilar structures visible on
fixed ostrich vessel. Stri-
ations are seen in both
(E) and (F) that may rep-
resent endothelial cell
junctions or alternatively
may be artifacts of the
fixation/dehydration
process. Scale bars in (A)
and (B), 40 mm; in (C)
and (D), 10 mm; in (E)
and (F), 1 mm.
Fig. 4. Cellular features
associated with T. rex
and ostrich tissues. (A)
Fragment of demin-
eralized cortical bone
from T. rex, showing
parallel-oriented fibers
and cell-like microstruc-
tures among the fibers.
The inset is a higher
magnification of one of
the microstructures seen
embedded in the fibrous
material. (B)Demin-
eralized and stained (3)
ostrich cortical bone,
showing fibrillar, parallel-
oriented collagen matrix
with osteocytes embed-
ded among the fibers.
The inset shows a high-
er magnification of one
of the osteocytes. Both
inset views show elon-
gate bodies with multi-
ple projections arising
from the external sur-
face 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)Fixedostrich
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 mm; in (C) and (D), 20 mm; in (E), 10 mm; in (F), 1 mm.
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gen fibers of demineralized ostrich bone (Fig.
4B, inset). These cell-like microstructures
could be isolated and, when subjected to al-
dehyde fixation (3), appeared to possess in-
ternal contents (Fig. 4C), including possible
nuclei (Fig. 4C, inset). These microstructures
are similar in morphology to fixed ostrich
osteocytes, both unstained (Fig. 4D) and
stained (3) for better visualization (Fig. 4D,
inset). SEM verifies the presence of the fea-
tures seen in transmitted light microscopy,
and again, projections extending from the
surface of the microstructures are clearly vis-
ible(Fig.4,EandF).
The fossil record is capable of exceptional
preservation, including feathers (4–6), hair (7),
color or color patterns (7, 8), embryonic soft
tissues (9), muscle tissue and/or internal organs
(10–13), and cellular structure (7, 14–16).
These soft tissues are preserved as carbon
films (4, 5, 10) or as permineralized three-
dimensional replications (9, 11, 13), but in
none of these cases are they described as still-
soft, pliable tissues.
Mesozoic fossils, particularly dinosaur fos-
sils, are known to be extremely well preserved
histologically and occasionally retain molecu-
lar information (6, 17, 18), the presence of
which is closely linked to morphological
preservation (19). Vascular microstructures
that may be derived from original blood ma-
terials of Cretaceous organisms have also been
reported (14–16).
Pawlicki was able to demonstrate osteo-
cytes and vessels obtained from dinosaur
bone using an etching and replication tech-
nique (14, 15). However, we demonstrate the
retention of pliable soft-tissue blood vessels
with contents that are capable of being liber-
ated from the bone matrix, while still retain-
ing their flexibility, resilience, original hollow
nature, and three-dimensionality. Additionally,
we can isolate three-dimensional osteocytes
with internal cellular contents and intact, sup-
ple filipodia that float freely in solution. This
T. rex also contains flexible and fibrillar bone
matrices that retain elasticity. The unusual
preservation of the originally organic matrix
may be due in part to the dense mineralization
of dinosaur bone, because a certain portion of
the organic matrix within extant bone is intra-
crystalline and therefore extremely resistant to
degradation (20, 21). These factors, combined
with as yet undetermined geochemical and
environmental factors, presumably also
contribute to the preservation of soft-tissue
vessels. Because they have not been embed-
ded or subjected to other chemical treatments,
the cells and vessels are capable of being
analyzed further for the persistence of molec-
ular or other chemical information (3).
Using the methodologies described here,
we isolated translucent vessels from two other
exceptionally well-preserved tyrannosaurs
(figs. S1 and S2) (3), and we isolated micro-
structures consistent with osteocytes in at least
three other dinosaurs: two tyrannosaurs and
one hadrosaur (fig. S3). Vessels in these spec-
imens exhibit highly variable preservation,
from crystalline morphs to transparent and
pliable soft tissues.
The elucidation and modeling of processes
resulting in soft-tissue preservation may form
the basis for an avenue of research into the
recovery and characterization of similar struc-
tures in other specimens, paving the way for
micro- and molecular taphonomic investiga-
tions. Whether preservation is strictly morpho-
logical and the result of some kind of unknown
geochemical replacement process or whether
it extends to the subcellular and molecular
levels is uncertain. However, we have identi-
fied protein fragments in extracted bone sam-
ples, some of which retain slight antigenicity
(3). These data indicate that exceptional mor-
phological preservation in some dinosaurian
specimens may extend to the cellular level or
beyond. If so, in addition to providing in-
dependent means of testing phylogenetic
hypotheses about dinosaurs, applying molecu-
lar and analytical methods to well-preserved
dinosaur specimens has important implica-
tions for elucidating preservational mi-
croenvironments and will contribute to our
understanding of biogeochemical interac-
tions at the microscopic and molecular
levels that lead to fossilization.
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22. We thank C. Ancell, J. Barnes, D. Enlow, J. Flight, B.
Harmon, E. Lamm, N. Myrhvold, A. de Ricqles, and A.
Steele for funding, preparation, insight, consultation,
and valued feedback; and J. Fountain and K. Padian
for editorial advice. Research was funded by North
Carolina State University as well as by grants from
N. Myhrvold (J.R.H.) and NSF (M.H.S.).
Supporting Online Material
www.sciencemag.org/cgi/content/full/307/5717/1952/
DC1
Materials and Methods
Figs. S1 to S5
References
7 December 2004; accepted 26 January 2005
10.1126/science.1108397
Glycan Foraging in Vivo
by an Intestine-Adapted
Bacterial Symbiont
Justin L. Sonnenburg,
1,2
Jian Xu,
1,2
Douglas D. Leip,
1,2
Chien-Huan Chen,
1,2
Benjamin P. Westover,
1,3
Jeremy Weatherford,
3
Jeremy D. Buhler,
1,3
Jeffrey I. Gordon
1,2
*
Germ-free mice were maintained on polysaccharide-rich or simple-sugar diets
and colonized for 10 days with an organism also found in human guts,
Bacteroides thetaiotaomicron, followed by whole-genome transcriptional
profiling of bacteria and mass spectrometry of cecal glycans. We found that
these bacteria assembled on food particles and mucus, selectively induced
outer-membrane polysaccharide-binding proteins and glycoside hydrolases,
prioritized the consumption of liberated hexose sugars, and revealed a
capacity to turn to host mucus glycans when polysaccharides were absent
from the diet. This flexible foraging behavior should contribute to ecosystem
stability and functional diversity.
The adult human body is a composite of many
species. Each of us harbors È10timesasmany
microbial cells as human cells (1). Our resident
microbial communities provide us with a variety
of metabolic capabilities not encoded in our
genome, including the ability to harvest other-
wise inaccessible nutrients from our diet (2). The
intestine contains an estimated 10 trillion to 100
trillion microorganisms that are largely members
of Bacteria but include representatives from
R EPORTS
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... Thus, the preserved state of a fossil/sub-fossil's biomolecular histology (which includes molecular sequences), is representative of the combined effect of these diagenetic variables upon its molecular sequences. Substantial precedence exists in the scientific literature for the preservation of remnant cells and tissues within ancient vertebrate specimens 29,[35][36][37][38][39][40][41][42][43][44][45][46][47] . Data characterizing the biomolecular histology of such remains is herein hypothesized to be usable as a proxy for molecular sequence preservation. ...
... Testing this hypothesis can be accomplished using a suite of molecular techniques capable of characterizing both the morphological 36,39,40,42,47,48 and chemical 29,30,36,38,43,49,50 aspects of biomolecular histology. Such data can then be used to identify connections between a specimen's observed biomolecular histology and its degree of molecular sequence preservation. ...
... These biomolecular tissue portions would then be observable unhindered by biogenic minerals. Observations of properties of these biomolecular structures such as flexibility, robustness, and color, among others, can then be readily made using light microscopy, and surface structure is less obscured during electron microscope imaging 35,39,40,43 . The absence of~67nm banding in type-1 collagen fibrils, for example, of demineralized collagenous matrix directly evidences a substantial degree of collagen sequence degradation 71,76,77 . ...
Preprint
Researcher ability to accurately screen fossil and sub-fossil specimens for preservation of DNA and protein sequences remains limited. Thermal exposure and geologic age are usable proxies for sequence preservation on a broad scale but are of limited use for specimens of similar depositional environments and/or ages. Cell and tissue biomolecular histology is thus proposed as a proxy for determining sequence preservation potential of ancient specimens with improved accuracy. Biomolecular histology as a proxy is hypothesized to elucidate why fossil/sub-fossils of some depositional environments and or geologic ages preserve sequences while others do not and to facilitate selection of ancient specimens for use in molecular studies.
... Schweitzer et al. (2007b) identified blood vessels in specimens of Tyrannosaurus rex (65 and 68 Ma), Triceratops horridus (65 Ma), and Brachylophosaurus canadensis (78 ma). In one case, T. rex vessels with endothelial cell nuclei were reported (Schweitzer et al. 2005a). Schweitzer and colleagues have even developed protocols for the isolation of blood vessels from the fossil bones of Brachylophosaurus canadensis and other species (Cleland et al. 2015). ...
... Initial reports of small red intravascular microstructures in bones of Tyrannosaurus rex, some of which were described as having "opaque central regions," were published by Schweitzer et al. (1997aSchweitzer et al. ( , 1997b. Similar results were subsequently obtained with the same specimen and two different specimens of T. rex (Schweitzer and Horner 1999;Schweitzer et al. 2005aSchweitzer et al. , 2007a. Schweitzer et al. (2005a) also reported the presence of structures "morphologically consistent with endothelial cell nuclei" in T. rex blood vessels. ...
... Similar results were subsequently obtained with the same specimen and two different specimens of T. rex (Schweitzer and Horner 1999;Schweitzer et al. 2005aSchweitzer et al. , 2007a. Schweitzer et al. (2005a) also reported the presence of structures "morphologically consistent with endothelial cell nuclei" in T. rex blood vessels. Small red microstructures/erythrocytes were also identified in bone tissues of a 1 Ka moa, a 300 Ka mammoth (Mammuthus columbi), and a 78 Ma specimen of Brachylophosaurus canadensis; however, such structures were not observed in the bone tissues of a 65 Ka mastodon Mammut americanum (Schweitzer et al. 2007a). ...
Chapter
Contrary to prevalent assumptions, blood—the ultimate “soft tissue”—has a substantial fossil record. Although initial reports of blood remnants from the Holocene were deservedly controversial—and reports of blood cells and proteins in Cretaceous therapods remain controversial today—there is currently good evidence for original blood components in fossils more than 500 million years old. In this review, our knowledge of the fossil record of blood and its cellular and molecular constituents is documented and appraised. Cellular components have been described from both amber (e.g., erythrocytes and protozoan parasites such as Plasmodium and Leishmania) and mineralized bone tissue (erythrocytes and capillary vessels). Although small molecules such as hemoglobin-derived heme and hemocyanin-derived copper are documented in the fossil record, sequenceable polymeric molecules proteins and DNA have the greatest potential for informing us of ancient behavior and physiology—examples include the functionality of mammoth hemoglobin and the disease states of pharaohs.
... The current study builds upon our prior work by examining the diagenetic history of another non-avian dinosaur preserved under drasticallydifferent paleoenvironmental and diagenetic circumstances within the Hell Creek Formation: Tyrannosaurus rex specimen MOR 1125. This specimen became one of the most widely-known fossils in the world when Schweitzer et al. [51,52] and Asara et al. [22] reported, respectively, the preservation of original bone cells, blood vessels, and pliable proteinaceous matrix in its right femur and both tibiae, as well as endogenous collagen I peptides in its right femur. Those studies of MOR 1125 ignited unprecedented interest in the now-growing field of molecular paleontology, so it is due time for the taphonomic and diagenetic history of this specimen to be resolved in comprehensive detail. ...
... Most of the bones are complete, though some exhibit transverse and longitudinal fractures stemming from minor post-fossilization compaction. None of the bones exhibit any noteworthy signs of weathering or abrasion, and the femur examined by Schweitzer et al. [51,52] and Asara et al. [22] exhibits infilling of the medullary cavity by crushed trabeculae and sedimentary matrix. ...
... Most of the bones are complete, though some exhibit transverse and longitudinal fractures stemming from minor post-fossilization compaction. None of the bones exhibit any noteworthy signs of weathering or abrasion, and the femur examined by Schweitzer et al. [51,52] and Asara et al. [22] exhibits infilling of the medullary cavity by crushed trabeculae and sedimentary matrix. Schweitzer et al. [51] (p. ...
Article
Full-text available
Many recent reports have demonstrated remarkable preservation of proteins in fossil bones dating back to the Permian. However, preservation mechanisms that foster the long-term stability of biomolecules and the taphonomic circumstances facilitating them remain largely unexplored. To address this, we examined the taphonomic and geochemical history of Tyrannosaurus rex specimen Museum of the Rockies (MOR) 1125, whose right femur and tibiae were previously shown to retain still-soft tissues and endogenous proteins. By combining taphonomic insights with trace element compositional data, we reconstruct the postmortem history of this famous specimen. Our data show that following prolonged, subaqueous decay in an estuarine channel, MOR 1125 was buried in a coarse sandstone wherein its bones fossilized while interacting with oxic and potentially brackish early-diagenetic groundwaters. Once its bones became stable fossils, they experienced minimal further chemical alteration. Comparisons with other recent studies reveal that oxidizing early-diagenetic microenvironments and diagenetic circumstances which restrict exposure to percolating pore fluids elevate biomolecular preservation potential by promoting molecular condensation reactions and hindering chemical alteration, respectively. Avoiding protracted interactions with late-diagenetic pore fluids is also likely crucial. Similar studies must be conducted on fossil bones preserved under diverse paleoenvironmental and diagenetic contexts to fully elucidate molecular preservation pathways.
... Isolated samples of these hollow, flexible tubes did not dissolve after multiple treatments with acetone, refuting the hypothesis that they are casts formed by the in-filling of acetone-soluble glues and/or field consolidates. The tapering bifurcation pattern observed in modern vessels and in reported soft tissues from other ancient vertebrates (e.g., [60,61]) was also observed among the recovered vessels from D. schrani ( Figure 9B). These vessels are inconsistent with fungal hyphae, which are cylindrical and grow from an apical tip extension [62,63] and, thus, do not taper when branching. ...
... Matrix recovered from D. schrani was soft, pliable, and fibrous in appearance, with encased elongated osteocytes oriented with their long axes parallel to one another ( Figure 9D). In general, osteocytes displayed shorter, blunted filopodia-like structures in comparison to those observed on putative osteocytes from other extinct taxa [13,60,61,[66][67][68]. It is not known if this is a result of tissue degradation during the time between the exhumation of the fossil and analyses, or an artifact of preservation caused by the specific depositional environment in which the specimen was entombed. ...
Article
Full-text available
Evidence that organic material preserves in deep time (>1 Ma) has been reported using a wide variety of analytical techniques. However, the comprehensive geochemical data that could aid in building robust hypotheses for how soft-tissues persist over millions of years are lacking from most paleomolecular reports. Here, we analyze the molecular preservation and taphonomic history of the Dreadnougtus schrani holotype (MPM-PV 1156) at both macroscopic and microscopic levels. We review the stratigraphy, depositional setting, and physical taphonomy of the D. schrani skeletal assemblage, and extensively characterize the preservation and taphonomic history of the humerus at a micro-scale via: (1) histological analysis (structural integrity) and X-ray diffraction (exogenous mineral content); (2) laser ablation-inductively coupled plasma mass spectrometry (analyses of rare earth element content throughout cortex); (3) demineralization and optical microscopy (soft-tissue microstructures); (4) in situ and in-solution immunological assays (presence of endogenous protein). Our data show the D. schrani holotype preserves soft-tissue microstructures and remnants of endogenous bone protein. Further, it was exposed to LREE-enriched groundwaters and weakly-oxidizing conditions after burial, but experienced negligible further chemical alteration after early-diagenetic fossilization. These findings support previous hypotheses that fossils that display low trace element uptake are favorable targets for paleomolecular analyses.
... Numerous molecular paleontological investigations have been conducted on geologically ancient fossils, (i.e., >1 Ma years old; [1]), many of which have demonstrated strong evidence for the preservation of endogenous biomolecules and soft tissues in deep time. These studies have yielded the recovery of cellular and tissue structures morphologically similar to their extant counterparts, (e.g., [2][3][4][5][6][7][8][9][10][11][12][13][14]), identified the presence of proteins in fossil soft cells and soft tissues via a variety of techniques, (e.g., [4][5][6]10,[15][16][17][18][19][20]), and even recovered protein sequences from mass spectrometry, (e.g., [4,[21][22][23][24]). The wealth of such discoveries, and the number of fossil taxa and preservational environments investigated and found to yield soft tissue and biomolecular preservation continues to grow. ...
Article
Full-text available
Endogenous biomolecules and soft tissues are known to persist in the fossil record. To date, these discoveries derive from a limited number of preservational environments, (e.g., fluvial channels and floodplains), and fossils from less common depositional environments have been largely unexplored. We conducted paleomolecular analyses of shallow marine vertebrate fossils from the Cretaceous–Paleogene Hornerstown Formation, an 80–90% glauconitic greensand from Jean and Ric Edelman Fossil Park in Mantua Township, NJ. Twelve samples were demineralized and found to yield products morphologically consistent with vertebrate osteocytes, blood vessels, and bone matrix. Specimens from these deposits that are dark in color exhibit excellent histological preservation and yielded a greater recovery of cells and soft tissues, whereas lighter-colored specimens exhibit poor histology and few to no cells/soft tissues. Additionally, a well-preserved femur of the marine crocodilian Thoracosaurus was found to have retained endogenous collagen I by immunofluorescence and enzyme-linked immunosorbent assays. Our results thus not only corroborate previous findings that soft tissue and biomolecular recovery from fossils preserved in marine environments are possible but also expand the range of depositional environments documented to preserve endogenous biomolecules, thus broadening the suite of geologic strata that may be fruitful to examine in future paleomolecular studies.
... Therefore, the upregulation of CGRP in response to divalent cations may possess multiple functions, including the nociceptive transmission contributing to central sensitization and the direct control of bone cells through the receptors they shared. The spiral-like TH + sympathetic nerve fibers typically wrap around the major blood vessels in the periosteum and penetrate the cortical bone via Volkmann's and Haversian canals 72,73 . They are known to be capable of regulating osteoblast activity through β2-adrenergic receptors (β2AR) 13,74 . ...
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Full-text available
Bone formation induced by divalent metal cations has been widely reported; however, the underlying mechanism is unclear. Here we report that these cations stimulate skeleton interoception by promoting prostaglandin E2 secretion from macrophages. This immune response is accompanied by the sprouting and arborization of calcitonin gene-related polypeptide-α ⁺ nerve fibers, which sense the inflammatory cue with PGE 2 receptor 4 and convey the interoceptive signals to the central nervous system. Activating skeleton interoception downregulates sympathetic tone for new bone formation. Moreover, either macrophage depletion or knockout of cyclooxygenase-2 in the macrophage abolishes divalent cation-induced skeleton interoception. Furthermore, sensory denervation or knockout of EP4 in the sensory nerves eliminates the osteogenic effects of divalent cations. Thus, our study reveals that divalent cations promote bone formation through the skeleton interoceptive circuit, a finding which could prompt the development of novel biomaterials to elicit the therapeutic power of these divalent cations.
... These deconvoluted peaks match very well with previously reported data (Warren et al., 2009;Gallagher, 2009). Complex organic matter preservation inside dinosaur bones have been reported (Schweitzer et al., 1997;Schweitzer & Horner, 1999;Bern et al.,2009;Asara et al., 2007;Martill & Unwin, 1997;Schweitzer et al., 1997Schweitzer et al., , 2005Schweitzer et al., , 2009). However, it was also interpreted as possible microbial biofilms (Peterson et al., 2010) and was also rebutted (Lindgren et al., 2011). ...
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Each chemical bond has unique vibration energy, which yields a certain characteristic peak(s) in Fourier-Transform Infrared Spectroscopy (FTIR). The alkyl (CH 3-, CH 2-) functional group, which exists in almost all organic compounds, will show two or more distinct absorption peaks in the 2800-3000 cm-1 range. Thus, if a given spectrum shows these peaks, we can safely say that the specimen contains the alkyl structure(s), which means organic compounds. Alkyl peaks can be used as a positive screening indicator without diving into the other IR spectra section. The overtone peaks, shapes, and intensity of carbonates in the 2800-3000cm-1 range are different from the alkyl group. This paper uses FTIR, including synchrotron radiation sr-FTIR, to examine 63 fossil specimens spanning across a long geological time and different taphonomic conditions and 15 extant specimens and nine matrices for comparisons. Each specimen was FTIR scanned multiple times. A total of 107 spectra were selected from 525 scans. The results indicate that preservation of organic remains in body fossils is a common phenomenon, not a particular case.
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The fossils are preserved remains of body parts or traces of ancient organisms. Sri Lanka is a continental island that evolved via unique geological formations, including fossil remains. This island represents many fossils belonging to three different geological periods, for instance: the Jurassic period, Miocene period, and Pleistocene epoch. Most of the Pleistocene fossils were found in terrestrial deposits (alluvial) from the Sabaragamuwa basin called Ratnapura fauna. Thus, our investigations focused on documenting samples of fossils gathered, under the project called “The Paleo World of Sabaragamuwa Basin - Sri Lanka” conducted by Eco Astronomy Inc (Sri Lanka). Considering the geological time scale, we are looking for reporting samples that approximately belong to the Quaternary period. As we know, the Quaternary period of the Earth’s geographic history includes two geologic epochs viz., which are: the Pleistocene (2.58 Myr to 0.0012 Myr), and the Holocene (0.0012 Myr to Present). Both epochs have changed and divided the fauna’s equilibrium and human’s cultural phases based on climate and sea�level fluctuations that took place during these periods. Some of the sections in those epochs has occurred during the last glacial maximum (LGM) and represent the mean sea level was much lower compared with the present records. Therefore, the quaternary period shows the open accessibility to migration of mammalian mega faunal species, that lived during the transition from the Pleistocene to the Holocene epoch. Most probably, the terrestrial climate change has impacted them and caused the extinction of those megafaunas. The gathered data details were synchronized via the technical aspect of sampling photography, toy photography, and virtual reality for analyses and reconstruction purposes.
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The fossils are preserved remains of body parts or traces of ancient organisms. Sri Lanka is a continental island that evolved via unique geological formations, including fossil remains. This island represents many fossils belonging to three different geological periods, for instance: the Jurassic period, Miocene period, and Pleistocene epoch. Most of the Pleistocene fossils were found in terrestrial deposits (alluvial) from the Sabaragamuwa basin called Ratnapura fauna. Thus, our investigations focused on documenting samples of fossils gathered, under the project called "The Paleo World of Sabaragamuwa Basin-Sri Lanka" conducted by Eco Astronomy Inc (Sri Lanka). Considering the geological time scale, we are looking for reporting samples that approximately belong to the Quaternary period. As we know, the Quaternary period of the Earth's geographic history includes two geologic epochs viz., which are: the Pleistocene (2.58 Myr to 0.0012 Myr), and the Holocene (0.0012 Myr to Present). Both epochs have changed and divided the fauna's equilibrium and human's cultural phases based on climate and sea-level fluctuations that took place during these periods. Some of the sections in those epochs has occurred during the last glacial maximum (LGM) and represent the mean sea level was much lower compared with the present records. Therefore, the quaternary period shows the open accessibility to migration of mammalian mega faunal species, that lived during the transition from the Pleistocene to the Holocene epoch. Most probably, the terrestrial climate change has impacted them and caused the extinction of those megafaunas. The gathered data details were synchronized via the technical aspect of sampling photography, toy photography, and virtual reality for analyses and reconstruction purposes.
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Dromaeosaurids, despite their notoriety, are poorly characterized meat-eating dinosaurs, and were previously known only from disarticulated or fragmentary specimens. Many studies have denied their close relationship to birds. Here we report the best represented and probably the earliest dromaeosaurid yet discovered, Sinornithosaurus millenii gen. et sp. nov., from Sihetun, the famous Mesozoic fish-dinosaur-bird locality in China. Sinornithosaurus not only greatly increases our knowledge of Dromaeosauridae but also provides evidence for a filamentous integument in this group. It is remarkably similar to early birds postcranially. The shoulder girdle shows that terrestrial dromaeosaurids had attained the prerequisites for powered, flapping flight, supporting the idea that bird flight originated from the ground up. The discovery of Sinornithosaurus widens the distribution of integumentary filaments among non-avian theropods. Phylogenetic analysis indicates that, among known theropods with integumentary filaments or feathers, Dromaeosauridae is the most bird-like, and is more closely related to birds than is Troodontidae.
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Histological analyses of trabecular tissue from the limb bones of a Tyrannosaurus rex revealed the presence of small (average 25 μm) round microstructures in the vascular channels of the bone. These bony tissues otherwise evidenced minimal diagenetic change, and no secondary mineral deposition was observed in the vessel channels. While we have published analyses of the bony tissues of this specimen, we have not published data obtained on these small intravascular microstructures. Several characteristics link these microstructures to endogenous biological components, although their origin is not confirmed, and several hypotheses are considered. A discussion of the meaning of the term ‘organic preservation’ and a suggestion of criteria that should be met to be described as such is included.
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Definitive non-avian dinosaur embryos, those contained inside fossil eggs, are rare. Here we describe the first known unequivocal embryonic remains of sauropod dinosaurs—the only known non-avian dinosaur embryos from Gondwana—from a nesting found in the Upper Cretaceous stage of Pagagonia, Argentina. At this new site, Auca Mahuevo, thousands of eggs are distributed over an area greater than 1 km sq. The proportion of eggs containing embryonic remains is high: over a dozen in-situ eggs and nearly 40 egg fragments incasing embryonic material were recovered. In addition to bone, these specimens contain large patches of fossil skin casts, the first definite portions of integument ever reported for a non-avian dinosaur embryo. As morphology of the eggs enclosing these osseous and integumentary remains is identical, we propose that these specimens belong to the same sauropod species. This discovery allows the confident association of the megaloolithid type of dinosaur eggshell with sauropod dinosaurs.
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Two different immunological assays were used to identify the remains of a bone matrix protein, osteocalcin (OC), in the bones of dinosaurs and other fossil vertebrates. Antibodies raised against OC from modern vertebrates showed strong immunological cross-reactivity with modern and relatively young fossil samples and significant reactions with some of the dinosaur bone extracts. The presence of OC was confirmed by the detection of a peptide-bound, uniquely vertebrate amino acid, gammacarboxyglutamic acid (Gla). Preservation of OC in fossil bones appears to be strongly dependent on the burial history and not simply on age. These results extend the range of protein preservation in the geologic record and provide a first step toward a molecular phylogeny of the dinosaurs.
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The mineralized soft tissue of a dinosaur, only the second discovery of its kind, is reported from the Low er Cretaceous of Las Koyas, Spain. Cellular details of mineralized skin and muscle of Pelecanimimus are replicated in an iron carbonate. The outline of this ornithomimosaur is preserved by a phosphatized microbial mat that enshrouded the carcass. It confirms the existence of either a throat pouch or dewlap, and soft occipital crest. This study confirms the importance of microbial mats in the fossilization of soft tissues and emphasises the need for careful monitoring of vertebrate remains for mineralized soft tissues prior to acid preparation.
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This overview is a summary of the state of understanding of processes and states in bone diagenesis, as seen from a chemical perspective. It deals with the significance and usefulness of the measurements of ‘diagenetic parameters’—that is, of measures of diagenetic alteration—and of the theories of physico–chemical processes which are considered to underlie the measured changes. In many ways these two aspects are seen to come together quite well, and some progress has been made in relating different burial environments to the observations of alteration. Such a framework also allows us to ask more penetrating questions, such as how characteristic differences in diagenetic alteration might arise, and how the pre–burial environment might influence the eventual course of diagenesis.