Mary Higby Schweitzer

Mary Higby Schweitzer is an American paleontologist at North Carolina State University, who led the groups that discovered the remains of blood cells in dinosaur fossils and later discovered soft tissue remains in the Tyrannosaurus rex specimen MOR 1125,[1][2] as well as evidence that the specimen was a pregnant female when she died.[3]

Mary Higby Schweitzer
NationalityAmerican
Alma mater
Scientific career
FieldsPaleontology

Biography
Schweitzer's mobile laboratory, Museum of the Rockies, Bozeman (Montana)

Schweitzer earned a B.S. in Communicative Disorders from Utah State University in 1977, and got a Certificate of Secondary Education in Broadfield Science from Montana State University in 1988. Under the direction of mentor Jack Horner, she received her Ph.D. in Biology from Montana State University in 1995.

She has three children.[4]

Based at North Carolina State University, Schweitzer is currently researching Molecular Paleontology, molecular diagenesis and taphonomy, evolution of physiological and reproductive strategies in dinosaurs and their bird descendants, and astrobiology.[5]

Discoveries

In 2000, Bob Harmon, chief preparator of paleontology at the Museum of the Rockies, discovered a Tyrannosaurus skeleton in the Hell Creek Formation in Montana. After a two-year retrieval process, Jack Horner, director of the Museum, gave the femur bone to Schweitzer. Schweitzer was able to retrieve proteins from this femur in 2007.[6]

Schweitzer was the first researcher to identify and isolate soft tissues from an ancient fossil bone. The soft tissues are collagen, a connective protein. Amino acid sequencing of several samples have shown matches with the known collagens of chickens, frogs, newts and other animals. Schweitzer has also isolated organic compounds and antigenic structures in sauropod egg shells.[7] With respect to the significance of her work, Kevin Padian, Curator of Paleontology, University of California Museum of Paleontology, has stated "Chemicals that might degrade in a laboratory over a short period need not do so in a protected natural chemical environment...it's time to readjust our thinking."[8]

Schweitzer previously announced similar discoveries in 1993.[9][10] Since then, the claim of discovering soft tissues in an ancient fossil has been disputed by some molecular biologists. Later research by Kaye et al.[11] published in PLoS ONE (30 July 2008) challenged the claims that the material found is the soft tissue of Tyrannosaurus. A more recent study (October 2010) published in PLoS ONE contradicts the conclusion of Kaye and supports Schweitzer's original conclusion.[12] Evidence for the extraction of short segments of ancient DNA from dinosaur fossils has been reported on two occasions.[13] The extraction of protein, soft tissue, remnant cells and organelle-like structures from dinosaur fossils has been confirmed.[14][15][16] Blood-derived porphyrin proteins have also been discovered in a mid Eocene mosquito fossil.[17]

In the developing field of paleoproteomics, Schweitzer has also discovered that iron particles may play a part in the preservation of soft tissue over geologic time.[18]

Awards and honors

On April 28, 2018, Schweitzer became the first recipient of the Dr. Elizabeth 'Betsy' Nicholls Award for Excellence in Palaeontology at the Canadian Fossil Discovery Centre's Dig Deep Gala event. As the award recipient Schweitzer was the keynote speaker and presented on her research.[19][20]

On March 20, 2019 the journal Nature Communications published a paper naming an extinct bird "Avimaia schweitzerae... in honor of Mary Higby Schweitzer for her ground-breaking works on MB [ medullary bone ] and for her role in establishing the field of molecular paleontology."[21]

References
  1. Schweitzer, Mary H.; Wittmeyer, Jennifer L.; Horner, John R. (2007). "Soft tissue and cellular preservation in vertebrate skeletal elements from the Cretaceous to the present". Proc Biol Sci. 274 (1607): 183–97. doi:10.1098/rspb.2006.3705. PMC 1685849. PMID 17148248.
  2. Hitt J (2005). "New discoveries hint there's a lot more in fossil bones than we thought". Discover. October. Archived from the original on February 22, 2007. Retrieved 2007-03-05.
  3. "Geologists Find First Clue To Tyrannosaurus Rex Gender In Bone Tissue". Science Daily. 2005-06-03. Retrieved 2007-03-05.
  4. Yeoman, Barry (2006). "Schweitzer's Dangerous Discovery". Discover (April).
  5. "Schweitzer bio page". NCSU.
  6. Wilfor, John Noble (April 12, 2007). "Scientists Retrieve Proteins From Dinosaur Bone". New York Times. Retrieved February 8, 2011.
  7. Schweitzer, Mary H.; Chiappe, L; Garrido, A.C; Lowenstein, J.M; Pincus, S.H (April 22, 2005). "Molecular preservation in Late Cretaceous sauropod dinosaur eggshells". Proceedings of the Royal Society B: Biological Sciences. 272 (1565): 775–784. doi:10.1098/rspb.2004.2876. PMC 1599869. PMID 15888409.
  8. Perlman, David (April 13, 2007). "T. Rex Tissue Offers Evolution Insights". San Francisco Chronicle.
  9. Schweitzer, Mary H. (Sep 23, 1993). "Biomolecule Preservation in Tyrannosaurus Rex". Journal of Vertebrate Paleontology. 13: 56A. doi:10.1080/02724634.1993.10011533.
  10. Schweitzer, Mary H.; Cano, R. J.; Horner, J. R. (Sep 7, 1994). "Multiple Lines of Evidence for the Preservation of Collagen and Other Biomolecules in Undemineralized Bone from Tyrannosaurus Rex". Journal of Vertebrate Paleontology. 14: 45A. doi:10.1080/02724634.1994.10011592.
  11. Kaye, Thomas G.; Gaugler, Gary; Sawlowicz, Zbigniew (July 30, 2008). Stepanova, Anna (ed.). "Dinosaurian Soft Tissues Interpreted as Bacterial Biofilms". PLOS ONE. 3 (7): e2808. doi:10.1371/journal.pone.0002808. PMC 2483347. PMID 18665236.
  12. Peterson, J. E.; Lenczewski, M. E.; Reed, P. S. (October 2010). Stepanova, Anna (ed.). "Influence of Microbial Biofilms on the Preservation of Primary Soft Tissue in Fossil and Extant Archosaurs". PLOS ONE. 5 (10): 13A. doi:10.1371/journal.pone.0013334. PMC 2953520. PMID 20967227.
  13. Schweitzer MH, Zheng W, Cleland TP, Bern M (2012-10-17). "Molecular analyses of dinosaur osteocytes support the presence of endogenous molecules". Bone. 52 (1): 414–23. doi:10.1016/j.bone.2012.10.010. PMID 23085295.
  14. San Antonio, James D.; Schweitzer, Mary H.; Jensen, Shane T.; Kalluri, Raghu; Buckley, Michael; Orgel, Joseph P. R. O. (2011-06-08). Van Veen, Hendrik W. (ed.). "Dinosaur Peptides Suggest Mechanisms of Protein Survival". PLOS ONE. 6 (6): e20381. doi:10.1371/journal.pone.0020381. PMC 3110760. PMID 21687667.
  15. Armitage, Mark H.; Anderson, Kevin L. (2013-02-13). "Soft sheets of fibrillar bone from a fossil of the supraorbital horn of the dinosaur Triceratops horridus". Acta Histochemica. 115 (6): 603–8. doi:10.1016/j.acthis.2013.01.001. PMID 23414624.
  16. Cleland, Timothy P.; Schroeter, Elena R. (2015-11-23). "Mass Spectrometry and Antibody-Based Characterization of Blood Vessels from Brachylophosaurus Canadensis". Journal of Proteome Research. 14 (12): 5252–5262. doi:10.1021/acs.jproteome.5b00675. PMC 4768904. PMID 26595531.
  17. Greenwalta, Dale E.; Gorevab, Yulia S.; Siljeströmb, Sandra M.; Roseb, Tim; Harbache, Ralph E. (2013-02-13). "Hemoglobin-derived porphyrins preserved in a Middle Eocene blood-engorged mosquito". Proceedings of the National Academy of Sciences. 110 (46): 18496–18500. doi:10.1073/pnas.1310885110. PMC 3831950. PMID 24127577.
  18. Schweitzer, Mary H.; Zheng, Wenxia; Cleland, Timothy P.; Goodwin, Mark B.; Boatman, Elizabeth; Theil, Elizabeth; Marcus, Matthew A.; Fakra, Sirine C. (January 2014). "A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time". Proc. R. Soc. B. 281 (1775): 20132741. doi:10.1098/rspb.2013.2741. PMC 3866414. PMID 24285202.
  19. "World renown fossil hunter accepts award of excellence in Manitoba | Watch News Videos Online". Global News. Retrieved 2018-04-29.
  20. "Dig Deep: Renowned Fossil Hunter to Keynote Morden Gala | ChrisD.ca". ChrisD.ca. 2018-01-28. Retrieved 2018-04-29.
  21. Bailleul, Alida; O’Connor, Jingmai (20 March 2019). "An Early Cretaceous enantiornithine (Aves) preserving an unlaid egg and probable medullary bone". Nature Communications. 10 (1): 1275. doi:10.1038/s41467-019-09259-x. PMC 6426974. PMID 30894527.
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