James A. Jensen

As an artist, he worked in most media.[2] His pastel and acrylic paintings, reflecting his love of flowers, landscapes, and his appreciation of American Indians. His painting are hung from Alaska to Florida. 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.

Kronosaurus queenslandicus before glass was added to exhibit. 1957-8

In 1956, Romer decided to mount a Kronosaurus 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. 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.[3]

Starting in 1972, because of the remarkable range of species and number of specimens, he focused on Dry Mesa near Delta, 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.

In 1973, Brigham Young University cooperated with producer Steve Linton and director John Linton in order to produce The Great Dinosaur Discovery, a 1-hour-long color documentary showing Jensen's on-site finds in Dry Mesa. First released on November 13, 1973, in local "Egyptian Theater" in Delta, and subsequently aired on several USA TV channels, The Great Dinosaur Discovery was originally planned to be trimmed to about 30 minutes for educational use.[1] Indeed, to obtain a shortened educational version, the full-length documentary was reduced to a 24-minute-long mini-film which started airing on American television channels throughout the US as of 1976.

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-Supersaurus.

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.

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.[14]

The technique for mounting free-standing dinosaurs was developed by Jensen in 1957, while participating in the mount of Kronosaurus queenslandicus.[15]

Allosaurus skull suspended on little finger

Because of Jensen's experience in manufacturing, he was aware of techniques, equipment and materials not generally used in museum displays. For example, in 1958, he pioneered the use of a novel industrial product, "rigid foam", for casting dinosaur bones as illustrated by the adjacent photo of an allosaurus skull cast in foam.[16] He worked at the time in the Department of Vertebrate Paleontology, Museum of Comparative Zoology, in the Peabody Museum at Harvard University. By experimenting with an Allosaurus skull he refined the technique and then published his findings in 1961.[17]

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.

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.[18] 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.

The BYU Museum of Paleontology was built around Jensen's collection.