Moabosaurus

''Moabosaurus'' (meaning "Moab reptile") is a genus of turiasaurian sauropod dinosaur from the Early Cretaceous Cedar Mountain Formation of Utah, United States.

Description

''Moabosaurus'' is characterized by a suite of features including: extremely low neural spines that are thin, transverse ridges in the posterior cervical vertebrae and anterior dorsal vertebrae; strongly procoelous proximal and distal caudal vertebrae; and an ulna with well-developed lateral and medial anteroproximal ridges combined with a large olecranon process.

According to the 2017 article which officially named and described ''Moabosaurus'', the animal was said to reach 10 meters (32.8 feet) long. However, the specimens which were examined belonged to juveniles and sub-adults, so it's possible that the creature measured longer when fully-grown.

Discovery and naming

''Moabosaurus'' was collected from the Dalton Wells Quarry, which is about 20 km northwest of Moab, Utah. The quarry produced parts of at least 18 individuals of ''Moabosaurus'' based on the number of braincases present, totalling over 5,500 bones. Many of the recovered bones are fragmentary due to intense trampling as evidenced by breakage and trample scratches.Britt, B.B., Eberth, D.A., Scheetz, R.D., Greenhalgh, B.W., Stadtman, K.L., 2009. Taphonomy of debris-flow hosted dinosaur bonebeds at Dalton Wells, Utah (Lower Cretaceous, Cedar Mountain Formation, USA). Palaeogeography, Palaeoclimatology, Palaeoecology. 280(1-2):1-22. Another factor that degraded the bones before burial was consumption by insects. Insects, probably beetle larvae, consumed portions of the bones that were in contact with the ground, as evidenced by burrows and mandible marks. Later, the bones were transported a short distance by a stream and buried in sediments reworked from the underlying Morrison Formation.Eberth, D.A., Britt, B.B., Scheetz, R.D., Stadtman, K.L., and Brinkman, D.B., 2006. Dalton Wells: Geology and significance of debris-flow-hosted dinosaur bonebeds (Cedar Mountain Formation, eastern Utah, USA). Palaeoclimatology, Palaeoecology, Palaeoclimatology, 236:217-245. Detrital zircon crystals from the Dalton Wells Quarry yield an age of 125 million years, indicating ''Moabosaurus'' is Aptian in age.

Classification

Phylogenetic analyses in the describing article in 2017 indicated that ''Moabosaurus'' is a basal titanosauriform macronarian neosauropod. Unlike other titanosauriform sauropods it has thick-walled vertebrae with large pneumatic chambers (camerate-grade) as in basal macronarians and large, spatulate teeth, as in ''Camarasaurus''. However, a second study which was made in 2017 placed it in the Turiasauria, thus outside of the Neosauropoda. With ''Turiasaurus'' it shares derived features of the braincase; bifurcated cervical (neck) ribs; extremely low neural spines on the cervical and anterior dorsal vertebrae; and strongly procoelous proximal caudal vertebrae.

Paleoecology

The Dalton Wells quarry has also yielded specimens of ''Venenosaurus'' (a brachiosaurid sauropod), the theropod dinosaurs ''Utahraptor'' and ''Nedcolbertia'', plus a tall-spined iguanodontian, and the ankylosaurian '' Gastonia''. Non-dinosaurian taxa are rare at the quarry and are limited to fragments of a pterosaur, crocodilian, turtle, and a neochoristodere.Britt, B.B., R. D. Scheetz, D. B. Brinkman, and D. A. Eberth. 2006. A Barremian neochoristodere from the Cedar Mountain Formation, Utah, USA. Journal of Vertebrate Paleontology, 26(4): 1005-1008.

See also

*2017 in archosaur paleontology

References

{{Taxonbar, from=Q6886334

Early Cretaceous dinosaurs of North America
Turiasauria
Fossil taxa described in 2017