Mary Higby Schweitzer is an Americanpaleontologist atNorth Carolina State University, who led the groups that discovered the remains of blood cells in dinosaur fossils and later discovered soft tissue remains in theTyrannosaurus rex specimenMOR 1125,[1][2] as well as evidence that the specimen was a pregnant female when she died.[3]
In 2000, Bob Harmon, chief preparator of paleontology at theMuseum of the Rockies, discovered aTyrannosaurus skeleton in theHell Creek Formation in Montana. After a two-year retrieval process, Jack Horner, director of the Museum, gave thefemur bone to Schweitzer. Schweitzer was able to retrieve proteins from this femur in 2007.[6]
Schweitzer was the first researcher to identify and isolatesoft tissues from an ancient fossil bone. The soft tissues arecollagen, a connectiveprotein.Amino acid sequencing of several samples have shown matches with the known collagens ofchickens,frogs,newts and other animals. Schweitzer has also isolated organic compounds and antigenic structures insauropod 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 somemolecular biologists. Later research by Kaye et al.[11] published inPLoS ONE (30 July 2008) challenged the claims that the material found is the soft tissue ofTyrannosaurus. 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 ofpaleoproteomics, Schweitzer has also discovered that iron particles may play a part in the preservation of soft tissue over geologic time.[18]
On April 28, 2018, Schweitzer became the first recipient of the Dr.Elizabeth 'Betsy' Nicholls Award for Excellence in Palaeontology at theCanadian 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 journalNature 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]
^Schweitzer, Mary H. (Sep 23, 1993). "Biomolecule Preservation in Tyrannosaurus Rex".Journal of Vertebrate Paleontology.13: 56A.doi:10.1080/02724634.1993.10011533.
^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.
^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.PMID23085295.
^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.PMID23414624.
