Peter Lars Larson (born 1952) is an American paleontologist, fossil collector, and president of the Black Hills Institute of Geological Research. He led the team that excavated "Sue", the largest and most complete specimen of Tyrannosaurus rex found to date, and has published numerous scientific and popular works on dinosaur paleontology. He is criticized by some academic paleontologists for his commercial enterprises and support of private collections, but defended by others. 
Early life and education
Peter Larson grew up on a ranch near Mission, South Dakota. He began rock hunting at the age of four on his parent's ranch. He attended the South Dakota School of Mines to study paleontology. He graduated with a bachelor's degree in 1974. Shortly after graduating college he started Black Hills Minerals.
Larson founded what eventually became the Black Hills Institute in 1974. Partners Robert Farrar and (Larson's brother) Neal Larson later joined the company. In 1990, Larson led the excavation of the Tyrannosaurus rex skeleton later named "Sue". With only a bachelor's degree in geology, Larson has written and co-authored numerous publications on dinosaurs, has excavated more T. rex skeletons than any other paleontologist, and his organization's work on excavation and preparation of fossils has been recognized by paleontologists Robert Bakker, Philip Currie, Phillip Manning, and Jack Horner for its quality. He was one of the first to work with T. rex bone pathologies, has worked to uncover sexual dimorphism in the chevron length of T. rex, and argues that the controversial tyrannosaurid Nanotyrannus is not a juvenile T. rex, as some claim.
In 1992, Larson's team helped to discover second largest Tyrannosaurus rex Stan. Larson, along with paleontologist Kenneth Carpenter, edited the scholarly text Tyrannosaurus Rex, the Tyrant King. Larson and his ex-wife Kristin Donnan wrote the book Rex Appeal, which relates the story of how the U.S. Government took possession of the "Sue" T. rex skeleton following its excavation, and Bones Rock!, a children's book about the history of paleontology and requirements on how to become a palaeontologist.
Federal lands dispute
In 1992, an Acting United States Attorney led about 35 F.B.I. agents and 20 National Guardsmen on a raid on the Black Hills Institute of Geological Research, Larson's company. The federal agents seized the skeleton of Sue, along with other fossils and records. Larson and associates believed they were excavating "Sue" on private land, and had paid the owner $5,000 for permission. The U.S. Attorney charged that the fossil had been illegally taken from land under Federal administration. In 1994, a Federal court ruled that "Sue" belonged to the landowner, an Indian whose deed was held in trust by the Bureau of Indian Affairs.  After the sale to the Field Museum, the landowner received $7.6 million. 
Following a trial on charges unrelated to the "Sue" T. rex find, Larson was convicted of two felonies and two misdemeanors, charges which some considered politically motivated. The felonies involved the "failure to fill out forms," which resulted from contested instructions from the judge. The trial record shows that the judge told the jury to ignore testimony from the government's own customs witnesses, testimony that normally would have resulted in acquittals in these charges. Richard Howard Battey sentenced Larson two years in federal prison despite the maximum sentence being only six months. In 2015, South Dakota lawmakers have petitioned Barack Obama for a formal full pardon of Larson.
Larson has developed a controversial standing among some academic paleontologists who object to his organization's commercial selling of fossils and his lack of pedigree, though Robert Bakker has backed Larson as a responsible paleontologist. To date, he has discovered the most T. rex skeletons, and is considered by some to have made some of the greatest paleontological discoveries of all time.
- Larson,P and Frey,E. "Sexual Dimorphism in the Abundant Upper Cretaceous Theropod, T. rex." Journal of Vertebrate Paleontology 12, Abstract 96, 3 September 1992.
- DePalma, R. A.; Burnham, D. A.; Martin, L. D.; Rothschild, B. M.; Larson, P. L. (2013). "Physical evidence of predatory behavior in Tyrannosaurus rex". Proceedings of the National Academy of Sciences. 110 (31): 12560–12564. PMC . PMID 23858435. doi:10.1073/pnas.1216534110.
- Larson, P. and Donnan, K. "Rex Appeal". Montpelier, VT: Invisible Cities Press, 2002.
- Larson, P. and Carpenter, K. "Tyrannosaurus Rex, the Tyrant King (Life of the Past)". Indiana University Press, 2008.
- Larson, Peter; Kristin Donnan (2004). Bones rock! Everything you need to know to become a paleontologist. Montpelier, Vt.: Invisible Cities Press. ISBN 193122935X.
- Sue Hendrickson, discoverer and namesake of the T.rex "Sue"
- Dinosaur renaissance
- Paleontology in South Dakota
- Mullen, William (January 21, 2003). "Bones of contention: Academics and commercial fossil hunters may never settle their differences". Chicago Tribune.
- Browne, Malcolm W. (July 21, 1992). "A Dinosaur Named Sue Divides Fossil Hunters". New York Times.
- Rooney, Brian (Nov 13, 2007). "Racing Against Time and Weather for Dinosaur Bones". ABC News. Retrieved 26 April 2014.
- Alden, John (August 11, 2002). "'Rex Appeal' - one historic fossil, three stories". The Baltimore Sun.
- Switek, Brian (23 October 2013). "(News Feature) Palaeontology: The truth about T. rex". Nature. 502 (7472): 424–426. doi:10.1038/502424a.
- Smith, Matt (June 4, 2013). "Triceratops trio unearthed in Wyoming". CNN. Retrieved 18 April 2014.
- Browne, Malcolm (February 22, 1996). "Fossil Dealer, Target of Federal Prosecutors, Begins Jail Term". New York Times. Retrieved 18 April 2014.
- Steve Fiffer (2000). Tyrannosaurus Sue. W. H. Freeman and Company, New York. ISBN 0-7167-4017-6. Chapter 12 "Everything Changed that Day".
- Kjærgaard, Peter C. (June 2012). "The Fossil Trade: Paying a Price for Human Origins". ISIS. 103 (2): 340–355. JSTOR 10.1086/666365.
- Larson & Donnan, Peter & Kristin (2002). Rex Appeal: The Amazing Story of Sue, the Dinosaur That Changed Science, the Law, and My Life. Invisible Cities Press. Note: primary source, written by Larson.
- Associated Press. "Panel calls for pardon of famous paleontologist credited in discovery of 'Sue' the T. rex". Chicago Tribune.
- Collaborator Profile, University of Manchester Paleontology
- Peter Larson on IMDb
- Black Hills Institute of Geological Research Inc. website