James "Jim" Henry Madsen Jr. (July 28, 1932 – November 28, 2009) was an American vertebrate paleontologist and geologist and main leader of excavations at the

Cleveland-Lloyd Dinosaur Quarry Jurassic National Monument, at the site of the Cleveland-Lloyd Dinosaur Quarry, well known for containing the densest concentration of Jurassic dinosaur fossils ever found, is a paleontological site located near Cleveland, Utah, in the San Rafa ...

in the 1960s. Madsen primarily worked to describe skeletons of ''

Allosaurus ''Allosaurus'' ( ) is an extinct genus of theropod dinosaur that lived 155 to 145 million years ago during the Late Jurassic period ( Kimmeridgian to late Tithonian ages). The first fossil remains that could definitively be ascribed to th ...

'' from the quarry, eventually getting the site to become a

National Natural Landmark The National Natural Landmarks (NNL) Program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only national natural areas program that identifies and recognizes the best e ...

in 1965 and a

national monument A national monument is a monument constructed in order to commemorate something of importance to national heritage, such as a country's founding, independence, war, or the life and death of a historical figure. The term may also refer to a sp ...

after his death.

Biography

James Henry Madsen Jr. was born to James Henry Madsen Sr. and Eva Anne Weidner on July 28, 1932, in

Murray, Utah Murray () is a city situated on the Wasatch Front in the core of Salt Lake Valley in the U.S. state of Utah. Named for territorial governor Eli Murray, the city had a population of 50,637 as of the 2020 United States Census. Murray shares borde ...

and married his wife Susan Sowles in 1956. Madsen Jr. had two children and four grandchildren, with a nephew and two nieces.

Paleontology

When Madsen graduated the University of Utah in 1959, few careers were open for geologists until the geologist and paleontologist William Lee Stokes selected Madsen to oversee the excavation of

Upper Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...

dinosaur fossils from the

in 1960.Madsen Jr, J. H. (1976). Allosaurus fragilis: a revised osteology. ''Utah Geological and Mining Survey Bulletin'', ''109'', 1-163. Madsen led excavations of the site for 5 years, recovering over 14,000 fossils, making it one of the most productive dinosaur quarries in the world. In 1974, Madsen named a new genus and species of theropod dinosaur from Cleveland-Lloyd based on 2 partial ilia, naming it '' Stokesosaurus clevelandi'' after his advisor and the

Cleveland Museum of Natural History The Cleveland Museum of Natural History is a natural history museum in University Circle, a district of educational, cultural and medical institutions approximately five miles (8 km) east of Downtown Cleveland, Ohio, United States. The ...

. Of the 14,000 fossils found at Cleveland-Lloyd, 10,000 were of the large carnivorous theropod ''

'' with elements from a young juvenile to an old adult represented that were later described by Madsen in 1976. Madsen along with Samuel Paul Welles published an osteology of two ''

Ceratosaurus ''Ceratosaurus'' (from Greek 'horn' and 'lizard') is a genus of carnivorous theropod dinosaur that lived in the Late Jurassic period (Kimmeridgian to Tithonian ages). The genus was first described in 1884 by American paleontologist Othni ...

'' species they named, ''C. magnicornis'' & ''C. dentisulcatus,'' from

Grand Junction, Colorado Grand Junction is a List of municipalities in Colorado#Home rule municipality, home rule municipality that is the county seat and largest city of Mesa County, Colorado, United States. Grand Junction's population was 65,560 at the 2020 United St ...

and Cleveland-Lloyd respectively in 2000.

Public appearances

Madsen was featured on 2 episodes of the History channel television series '' Jurassic Fight Club'' in 2008, where he spoke about ''

,'' and other Upper Jurassic American dinosaurs featured in the show.

Legacy

In 2019, Madsen's student Daniel Chure and Mark Loewen described a new species of ''

'', which they named ''Allosaurus jimmadseni'' after Madsen's work on ''Allosaurus'' from Cleveland Lloyd Dinosaur Quarry.

References

1932 births 2009 deaths {{Improve categories, date=June 2022 American paleontologists Scientists from Utah Paleontologists University of Utah alumni