Fruitadens

Live image of Fruitadens, reconstruction with spring-like structure of the skin on the back similar to the related genus Tianyulong.

• Colorado, USA ( Morrison Formation )

• Fruitadens haagarorum

Fruitadens is a genus of dinosaur from the group of Heterodontosauridae that lived in North America during the Late Jurassic (late Kimmeridgian to early Tithonian ). Fossils have been found in the 1970s, but scientifically described by paleontologists to Richard Butler in 2009. Fruitadens was one of the smallest known dinosaurs. The only known species is Fruitadens haagarorum.

Features

Fruitadens was one of the smallest dinosaurs, and was, according to Butler and colleagues from the smallest previously known ornithischian. The largest specimens found is estimated to have a length of 65 to 75 centimeters and a weight of 500 to 750 grams. These specimens were among nearly mature animals that were with her ​​death about five years old. Like all members of this group had Fruitadens various teeth ( Heterodontie ) - as was found in the lower jaw, an enlarged, canine -like teeth that fit into a recess in the upper jaw. The upper jaw was missing an enlarged canine, unlike the related Echinodon. Unique among Ornithischiern was a small tooth in front of the enlarged canine tooth of the lower jaw, which was longer than high. The crowns of the remaining teeth were low and triangular.

Way of life

Fruitadens was as its relatives adapted to the running, as the lower portion of the hind leg was extended. He supported himself probably omnivorous ( omnivorous ), whereupon the shape and the degree of wear of the teeth indicates. Thus adaptations to plant food were less well developed than in Heterodontosaurus, for some researchers an optional Omnivorie is also suspected.

System

Fruitadens is counted among the Heterodontosauridae, a group of small, primitive ornithischian. The phylogenetic relationships within this group are not well known due to the incomplete fossil record. Butler and colleagues suggest, however, that Fruitadens has been Tucki more closely related than Heterodontosaurus with Echinodon becklesii. The following cladogram shows the possible position of Fruitadens within the Heterodontosauridae (after Butler, 2009):

Echinodon

Fruitadens

NHM RU A100

Heterodontosaurus

Location and naming

The fossils of Fruitadens were recovered by members of the Natural History Museum of Los Angeles County from the layers of the Morrison Formation ( Brushy Basin layer member ), a major fossil site. The site is located north- west of Grand Junction, Colorado.

So far, the fossil remains have been found of four individuals: The holotype specimen ( specimen number LACM 115747 ) consists of complete upper and lower jaws, some vertebrae ( neck, back, - sacrum - and caudal vertebrae ) as well as parts of one hind leg. A second copy ( copy number LACM 115727 ) consists of vertebrae and parts of the hind legs, while two others, derived from young animals copies ( copy numbers LACM 128258 and LACM 120478 ) from pine trees, some vertebrae and parts consist of the front and hind legs.

The name Fruitadens has a named after the city of Fruita excavation site in Colorado, where the fossils were discovered; the ending dens is Latin for " tooth." The Artepitheth haagorum honors Paul Haaga, Paul Haaga Jr., Heather Haaga, Blythe Haaga, Paul Haaga III and Catalina Haaga, which the Natural History Museum of Los Angeles County foster critical.