James A. Jensen
Encyclopedia
Barnum Brown
Barnum Brown , a paleontologist born in Carbondale, Kansas, and named after the circus showman P.T. Barnum, discovered the second fossil of Tyrannosaurus rex during a career that made him one of the most famous fossil hunters working from the late Victorian era into the early 20th century.Sponsored...
during the early 20th century. He was given the name "Dinosaur Jim" during the media coverage of his activities. Perhaps his most significant contribution to paleontology was to replace the 19th-century web of external metal struts, straps and posts that had been used to mount dinosaurs with a system of supports which were placed inside of bones, which produced free-standing skeletons with few or no obvious supports.
He is credited with naming and describing Supersaurus
Supersaurus
Supersaurus is a genus of diplodocid sauropod dinosaur discovered by Vivian Jones of Delta, Colorado, in the Upper Jurassic Morrison Formation of Colorado in 1972. The fossil remains came from the Brushy Basin Member of the formation, dating to about 153 million years ago...
(1985) and Torvosaurus
Torvosaurus
Torvosaurus is a genus of large theropod dinosaur that lived during the Late Jurassic period...
(with Peter Galton
Peter Galton
Peter M. Galton is a British vertebrate paleontologist working in America, who has to date written or co-written about a hundred papers in scientific journals or chapters in paleontology textbooks, especially on ornithischian and prosauropod dinosaurs.With Robert Bakker in a joint article...
, 1979).
Life to 1956
Jensen was born in 1918 in LeamingtonLeamington, Utah
Leamington is a town in Millard County, Utah, United States. The population was 217 at the 2000 census.-Geography:Leamington is located at ....
, Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
and developed an interest as a child exploring the desert and mountains with his father. While working in the now-defunct mining town of Mercur, Utah
Mercur, Utah
Mercur is a historical hard rock mining ghost town located at in Tooele County, Utah, USA. Its elevation from sea level is approximately 2,042m...
, he met his future wife, Marie M Merrell. Neither had finished high school, which limited their options. Casting about for ways to begin their life, they decided to take advantage of the Federal Homestead Act and settled in Seward, Alaska
Seward, Alaska
Seward is a city in Kenai Peninsula Borough in the U.S. state of Alaska. According to 2005 Census Bureau estimates, the population of the city is 3,016....
which was still an unpopulated frontier. They married in 1941, and identified the plot of land that they intended to homestead.
However, in anticipation of World War II, the U.S. Army moved into Seward in July, 1941, and started construction on Fort Raymond. The massive influx of military personnel forced many civilians, including them, to return to the "Lower Forty-eight". They settled in Salt Lake City, and had two sons. He went through a crash training program on the University of Utah
University of Utah
The University of Utah, also known as the U or the U of U, is a public, coeducational research university in Salt Lake City, Utah, United States. The university was established in 1850 as the University of Deseret by the General Assembly of the provisional State of Deseret, making it Utah's oldest...
campus to become a machinist and welder. Upon completing the brief program, he received an appointment as a civilian contractor from the federal government, then went to Hanford, WA to work on nuclear "Reactor B" pile of the Manhattan Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...
, after which he transferred to Pearl Harbor
Pearl Harbor
Pearl Harbor, known to Hawaiians as Puuloa, is a lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. Much of the harbor and surrounding lands is a United States Navy deep-water naval base. It is also the headquarters of the U.S. Pacific Fleet...
to work in the reconstruction. Jensen returned to Utah in 1945, where he worked at odd jobs such as washing machine repairman, creamery man, truck driver, ceramics, gunsmith, linoleum block printing, sculpting, welder, machinist, taxidermist, inventor, and writer. During this time he met Arnie Lewis who worked at the Utah Field House of Natural History
Utah Field House of Natural History
The Utah Field House of Natural History State Park Museum is a museum in Vernal, Utah, United States.-State park:The Utah Field House of Natural History State Park consists of a structure on a property...
. They became friends and Lewis hired him to mount several birds of prey, later moving to the Museum of Comparative Zoology at Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
. In 1951, Jensen and family went to Seward, Alaska where he worked the next five years as a dockside longshoreman.
Artist and sculptor
As an artist, he worked in most media. His pastelPastel
Pastel is an art medium in the form of a stick, consisting of pure powdered pigment and a binder. The pigments used in pastels are the same as those used to produce all colored art media, including oil paints; the binder is of a neutral hue and low saturation....
and acrylic
Acrylic paint
Acrylic paint is fast drying paint containing pigment suspension in acrylic polymer emulsion. Acrylic paints can be diluted with water, but become water-resistant when dry...
paintings, reflecting his love of flowers, landscapes, and his appreciation of American Indians. His painting are hung from Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
to Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
. In 1972, the Humble Oil Company listed him in a publication of artists of Alaska as one of the best-known pre-WW II artist. He sculpted in stone and metal, honing skills which were useful in developing a new system for mounting dinosaurs.
Harvard University 1956 to 1961
Alfred Sherwood Romer, Harvard UniversityHarvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
, hired Jensen in 1956, at the suggestion of Arnie Lewis. He was trained as a preparator in the Department of Vertebrate Paleontology in the Museum of Comparative Zoology of Peabody Museum. In addition to working on collections and exhibits for several departments, he participated in these collecting expeditions with Romer and Lewis during those five years:
- Nova ScotiaNova ScotiaNova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...
- FloridaFloridaFlorida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
- Thomas Farm - Ichigualasto in ArgentinaArgentinaArgentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, the first of 2 such expeditions - TexasTexasTexas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
- Boone Ranch - PennsylvaniaPennsylvaniaThe Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
- OhioOhioOhio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
- Clark Hill - Drumheller, AlbertaDrumheller, AlbertaDrumheller is a town within the Red Deer River valley in the badlands of east-central Alberta, Canada. It is located northeast of Calgary...
, CanadaCanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean... - West VirginiaWest VirginiaWest Virginia is a state in the Appalachian and Southeastern regions of the United States, bordered by Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest, Pennsylvania to the northeast and Maryland to the east...
- Greer Quarry - MontanaMontanaMontana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
- Hell Creek - WyomingWyomingWyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
- McGrew Ranch
Kronosaurus queenslandicus
Kronosaurus
Kronosaurus is an extinct genus of short-necked pliosaur. It was among the largest pliosaurs, and is named after the leader of the Greek Titans, Cronus.-Discovery and species:Kronosaurus lived in the Early Cretaceous Period ....
queenslandicus skeleton and had to obtain an unusually large amount of money to do the job. This was because the weight of the final mount was estimated to exceed the carrying capacity of the floor on which it would rest, due to the large amount of steel that would be used in preparing the mount. Therefore, architects drafted plans for a large I-beam to span the entire width of the building. Then two large holes were opened in the external walls and permanent mounts were created on each wall to hold the beam. Cranes then raised and inserted the beam into the holes so that it spanned the entire floor and was then secured to the two mounts. Romer Lewis and Jensen decided how to mount Kronosaurus. Jensen had plans showing how to mount a dinosaur without visible supports, plans which relied on his talents as an artist, sculptor, house framer, machinist and welder. Romer gave his approval to attempt a free standing mount. The plans were modified to suit the actual skeleton and Kronosaurus became the first mount done anywhere without visible structural members. All supporting bars, beams and sheets of metal and wood were integrated into or behind the bones. In addition to the unique method of concealing structural elements, Jensen used a curved back wall that had no corners to create the trompe d'oeil effect of a floating skeleton. There were no corners, vertical walls, or lines which would create the impression that the Kronosaurus was standing on the floor.
Brigham Young University 1961 - 1984
When he went to Brigham Young University, http://dinosaurjim.com/html/byu_.html he helped develop the Paleontology program. He worked in the field every summer amassing a large collection of packaged bones in matrix. He continued to refine new mounting techniques, prepared specimens, describing some, and attempted unsuccessfully to obtain funding for an earth sciences museum. The bulk of his summer work was done in Western Colorado and Utah. In addition, he went on a second six-month expedition with Harvard University to Ichigualasto, ArgentinaArgentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, and went to Antarctica for three months in an expedition headed up by Ohio State University. His most significant find in Antarctica was a maxilla of a Lystrosaurus on Coalsack Bluff.
Dry Mesa Quarry
Starting in 1972, because of the remarkable range of species and number of specimens, he focused on Dry MesaDry Mesa Quarry
The Dry Mesa Dinosaur Quarry is situated in southwestern Colorado, USA, near the town of Delta. Its geology forms a part of the Morrison Formation and has famously yielded a great diversity of animal remains from the Jurassic Period, among them Ceratosaurus, Supersaurus, and Torvosaurus...
in Western Colorado. He did work other locales, but the bulk of his collecting time was spent at Dry Mesa which is probably the richest dinosaur quarry discovered in North America in the second half of the 20th Century.
New dinosaurs
Following is a list of new species that Jensen described. While the descriptions are sound, his publications reflected his lack of formal training, resulting in errors made in the assignment of sauropod material from Dry Mesa. Caveat all descriptions of Ultrasauros-Ultrasaurus-Superaurus.| Species | Discoverer |
|---|---|
| Cathetosaurus lewisi | Jensen, 1988 |
| Dystylosaurus edwini | Jensen, 1985 |
| Hypsilophodon Hypsilophodon Hypsilophodon is an ornithopod dinosaur genus from the Early Cretaceous period of Europe. It was a small bipedal animal with an herbivorous or possibly omnivorous diet... wielandi |
Galton & Jensen, 1979 |
| Iguanodon Iguanodon Iguanodon is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs... ottingeri |
Galton & Jensen, 1979 |
| Palaeopteryx Palaeopteryx Palaeopteryx is a genus of theropod dinosaur now considered a nomen dubium. It was named and misidentified by J. A. Jensen in 1981, then redescribed by Jensen and K. Padian in 1989. At that time the binomial Palaeopteryx thomsoni was deemed invalid by Jensen... |
Jensen, 1981 |
| Supersaurus Supersaurus Supersaurus is a genus of diplodocid sauropod dinosaur discovered by Vivian Jones of Delta, Colorado, in the Upper Jurassic Morrison Formation of Colorado in 1972. The fossil remains came from the Brushy Basin Member of the formation, dating to about 153 million years ago... vivianae |
Jensen, 1985 |
| Torvosaurus Torvosaurus Torvosaurus is a genus of large theropod dinosaur that lived during the Late Jurassic period... tanneri |
Galton & Jensen, 1979 |
| Ultrasauros | Jensen vide Olshevsky, 1991 |
| Ultrasauros macintoshi | Jensen vide Olshevsky, 1991 |
He did not describe all of the new species that were identified as they were collected. Additional new species will be described for Dry Mesa as they are worked out and studied at BYU.
Publications
Although he didn't complete a formal education, Jensen starting publishing in the "Alaska Sportsman" in 1955, while working as a longshoreman in Seward, Alaska. A list of his publications available at this link.Free-standing mounts
The technique for mounting free-standing dinosaurs was developed by Jensen in 1957, while participating in the mount of KronosaurusKronosaurus
Kronosaurus is an extinct genus of short-necked pliosaur. It was among the largest pliosaurs, and is named after the leader of the Greek Titans, Cronus.-Discovery and species:Kronosaurus lived in the Early Cretaceous Period ....
queenslandicus.
Plastic foam casting and other experiments
Cooperation with rock hounds
As noted above, part of his success in finding specimens was due to his interest in "rock hounds" who jointly combed thousands of square miles of ground each year. He visited them every year or so, cultivating their friendship with gifts of dinosaur bones in return for information about their latest finds. In several instances, he named new dinosaurs after the person who led him to it.Education
Another legacy was Jensen's interest in educating the public about dinosaurs. He enthusiastically educated the public by welcoming them into his quarries each summer. He received hundreds of letters from school kids and answered them all. In spite of the fact that BYU denied Jensen a teaching role, he encouraged graduate students to take up the profession. Today, there is a small group of graduate students who became paleontologists as a result of his efforts.BYU Museum of Paleontology
The BYU Museum of PaleontologyBYU Museum of Paleontology
The Brigham Young University Museum of Paleontology was started in 1976 around the collection of James A. Jensen. For many years it was known as the BYU Museum of Earth Science, and most of the collection was in storage under the Lavell Edwards Stadium....
was built around Jensen's collection.
Ankle and foot versus feathers in arboreal life
Jensen collected "bird" bones in the Dry Mesa Quarry and became interested in the changes necessary for species to move from terrestrial to arboreal life. For him the sine qua non of arboreal life was not feathers. It was the ability of organisms to actually live in trees. This required that they be able to grasp branches, to build nests where they laid eggs and then reared young, and to sleep on small branches for many hours. Feathers don't confer these advantages to the foot or ankle. He studied ankles and feet of a wide range of mammals including a recently deceased elephant which was brought to him in a refrigerated railroad car, birds, amphibians and any creatures with leg bones and feet. His conclusion was that evolution of the ankle and foot was the fundamental change which had to occur so that species could move permanently, regardless of feathers or not, from the ground into the branches of trees. His research over several years on ankles and feet of various fossil and extant species supported this hypothesis. Ultimately he wrote an article discussing his hypothesis and findings and illustrated it with his own drawings of bones. But out of pique at the time at the world of paleontology, he had the article translated into Japanese and then published it in a Japanese science magazine.Honorary doctorate
In 1971, Jensen was granted an honorary doctorate by Brigham Young UniversityBrigham Young University
Brigham Young University is a private university located in Provo, Utah. It is owned and operated by The Church of Jesus Christ of Latter-day Saints , and is the United States' largest religious university and third-largest private university.Approximately 98% of the university's 34,000 students...
.
Selected works
- Jensen, James A. (1981) "A New Oldest Bird?" Anima: 33-39. Tokyo.
- Jensen, James A. (1985) "Uncompahgre dinosaur fauna: a preliminary report," Western North American Naturalist, Vol 45, No 4
- Jensen James A. (2001) The Road to Chilecito, Launceston, Tasmania: Queen Victoria Museum and Art GalleryQueen Victoria Museum and Art GalleryThe Queen Victoria Museum and Art Gallery is a museum located in Launceston, Tasmania, Australia. Established in 1891, the Queen Victoria has a strong reputation for its excellent collection, which includes fine exhibitions of colonial art, contemporary craft and design, Tasmanian history and...
. ISBN 9780958620352, .
External links
- Dinosaur Jim website - Consists of 186 unique URLs and more than 1,000 photos showing all of Jensen's digs while at Harvard University and Brigham Young University including his trip to Antarctica where he found Lystrosaurus.
- Museum Information, BYU Museum of PaleontologyBYU Museum of PaleontologyThe Brigham Young University Museum of Paleontology was started in 1976 around the collection of James A. Jensen. For many years it was known as the BYU Museum of Earth Science, and most of the collection was in storage under the Lavell Edwards Stadium....
, Brigham Young UniversityBrigham Young UniversityBrigham Young University is a private university located in Provo, Utah. It is owned and operated by The Church of Jesus Christ of Latter-day Saints , and is the United States' largest religious university and third-largest private university.Approximately 98% of the university's 34,000 students... - Jensen's entry on the Enchanted Learning site
- Kronosaurus queenslandicus: Ancient Monarch of the Seas
- "What is an Ultrasaurus?"
- Dinosaurs group 'S' on Wordquests
- Dinosaurs group 'T-Z' on Wordquests
- Kozak entry in the National Anthropological Archives