Ultrasauros

from Wikipedia, the free encyclopedia
This vertebra was once considered the holotype specimen of Ultrasauros - today it is ascribed to Supersaurus .

Ultrasauros is an invalid genus of dinosaurs . It was originally described by James A. Jensen in 1985 under the name Ultrasaurus , based on some very large bones thatwere discoveredin Colorado (USA) in1979. Later, however, the name had to bechanged to Ultrasauros , as the name Ultrasaurus was already given for a Korean dinosaur. In the public was Ultrasauros dubbed the largest known dinosaurs. In the following period (1996), however, the bones found turned out to be a mixture of Supersaurus and Brachiosaurus fossils. Today, ultrasauros , like the only type of ultrasauros macintoshi , arethereforeinvalid.

The name Ultrasauros means something like "over-lizard". The second part of the species name, macintoshi , honors John S. McIntosh for his important research in the field of sauropod dinosaurs.

Find history

Between 1972 and 1982, paleontologist James A. Jensen recovered a number of very large bones from the Dry Mesa Quarry , a quarry of the Morrison Formation in western Colorado famous for its numerous dinosaur finds. These bones were not found in the skeletal system, rather the bones of different species were mixed with one another. Nevertheless, in his scientific description of the finds published in 1985, Jenson comes to the conclusion that there are three previously unknown genera of sauropod dinosaurs: Supersaurus , Dystylosaurus and Ultrasauros . Ultrasauros was based on a dorsal vertebra ( holotype specimen), furthermore a caudal vertebra, a cervical vertebra and an exceptionally large shoulder girdle (scapulocoracoid) were assigned to this genus. All ultrasauros fossils were uncovered in 1979.

Size of the fossils

Jensen suspected that with Ultrasauros he discovered “probably the ultimate in size for a land animal”. Particularly noteworthy is the huge scapulocoracoid, which would measure 2.7 meters in height when erect. Accordingly, he chose the name Ultrasauros ("over-lizard"), which he had already informally used before the official first description published in 1985 . In various interviews and press articles, Jensen estimated the animal to be around 30 meters long and weigh around 70 tons. Various popular science books surpassed this estimate, giving weights of up to 180 tons. Curtice and colleagues (1996) state, however, that the “huge” scapulocoracoid was actually only 2.5 meters long, and not 2.7 meters, as Jensen originally stated. Consequently, this bone belonged to an animal no larger than the largest known individuals of Giraffatitan (formerly known as Brachiosaurus brancai ); in fact, this animal was probably smaller than the largest known Giraffatitan specimen.

Further research history

After the first description in 1985, the validity of sauroposeidon was soon questioned. Paul (1988) assumed that Ultrasauros macintoshi was identical to Brachiosaurus altithorax . Horrocks (1989) suspected in an unpublished manuscript that Ultrasauros is a new species of Brachiosaurus , which he called Brachiosaurus macintoshi . Miller and colleagues (1991) first noticed that the dorsal vertebra (the holotype specimen) shows similarities to the Supersaurus fossils discovered at the same site . In a new investigation of the ultrasauros fossils, Curtice and colleagues (1996) were finally able to confirm that the vertebrae actually belong to Supersaurus and that the scapulocoracoid can be assigned to Brachiosaurus . Thus, Ultrasauros forms a younger synonym of Supersaurus .

Ultrasaurus or Ultrasauros ?

In 1983, the Korean paleontologist Haang Mook Kim described the sparse remains of a supposedly huge sauropod from Korea under the name Ultrasaurus . The US fossils were unofficially dubbed “Ultrasaurus” by Jensen shortly after their discovery; In order for a scientific name to be valid, however, it must be published in the form of an initial description . This did not happen until 1985 when the American bones were found. The rules of the International Code of Zoological Nomenclature (ICZN) stipulate, in the case of the same name, that the previously published name is valid and the more recent one must be changed. A proposed change to Jenson initially provided for the new name Jensenosaurus , which, however, did not suit Jenson - instead, he proposed the slightly modified name Ultrasaur o s .

Individual evidence

  1. ↑ a b c James A. Jensen: Three new sauropod dinosaurs from the Upper Jurassic of Colorado. In: Western North American Naturalist. Vol. 45, No. 4, 1985, ISSN  1527-0904 , pp. 697-709, here pp. 697, 701, 704 and 707, online .
  2. ^ A b c d Brian D. Curtice, Kenneth L. Stadtman, Linda J. Curtice: A reassessment of Ultrasauros macintoshi (Jensen, 1985). In: Michael Morales (Ed.): The Continental Jurassic. Transactions of the Continental Jurassic Symposium, October 21-23, 1996, Museum of Northern Arizona, Flagstaff, Arizona (= Museum of Northern Arizona Press. Bulletin Series. Vol. 60). Museum of Northern Arizona, Flagstaff AZ 1996, ISBN 0-89734-119-8 , pp. 87-95, here pp. 87-88: History , digitized (PDF; 378,55) .
  3. ^ Donald F. Glut : Dinosaurs. The Encyclopedia. McFarland & Company, Jefferson NC et al. 1997, ISBN 0-89950-917-7 , pp. 961-963: Ultrasauros.
  4. ↑ Christopher McGowan: Dinosaurs, Spitfires, and Sea Dragons. Harvard University Press, Cambridge MA et al. 1992, ISBN 0-674-20770-X , p. 126.
  5. ^ Brian D. Curtice, Kenneth L. Stadtman, Linda J. Curtice: A reassessment of Ultrasauros macintoshi (Jensen, 1985). In: Michael Morales (Ed.): The Continental Jurassic. Transactions of the Continental Jurassic Symposium, October 21-23, 1996, Museum of Northern Arizona, Flagstaff, Arizona (= Museum of Northern Arizona Press. Bulletin Series. Vol. 60). Museum of Northern Arizona, Flagstaff AZ 1996, ISBN 0-89734-119-8 , pp. 87-95, here p. 93: Right Scapulocoracoid , digitized (PDF; 378.55) .
  6. ↑ Haang Mook Kim: [Lower Cretaceous Dinosaur Remains from Korea]. In: The Journal of the Geological Society of Korea. Vol. 19, No. 3, 1983, ISSN  0435-4036 , pp. 115-126, (In Korean language and script).