Probactrosaurus
Skeletal reconstruction of Probactrosaurus in Chinese palaeozoological Museum
- Dashuigou Formation ( Inner Mongolia, China)
- Probactrosaurus gobiensis
Probactrosaurus is an extinct genus of Iguanodontia from the group of ornithopods. Fossils were found in Inner Mongolia in China and are dated to the Early Cretaceous ( Albian ). They were described by Anatoly Konstantinovich Rozhdestvensky as Probactrosaurus in 1966. The only way is Probactrosaurus gobiensis.
Features
Probactrosaurus was a herbivorous dinosaur. Gregory Paul estimated a length of 5.5 meters, and set a weight of one ton of. Probactrosaurus was a lightly built Ornithopod with comparatively long and slender limbs. The thumb spike, which is typical of the Iguanodontia was small. It had a narrow snout, an elongated lower jaw and tooth batteries including a replacement tooth row.
Discovery and exploration history
While a Chinese expedition in the years 1959 and 1960 in Inner Mongolia, the fossils of a ornithopods were found and described in 1966 by Anatoly Konstantinovich Rozhdestvensky. Rozhdestvensky theorized that Probactrosaurus was a direct ancestor of Hadrosauriers Bactrosaurus, a now discredited theory. The genus name means " pre- Bactrosaurus "; the species name refers to the Gobi desert. The holotype PIN 2232/1 consists of a skull and the Postkranialskelett. He was found in the Dashuigou lineup. There is in addition to the holotype another copy, PIN 2232-10, that consists of a partial skeleton. Rozhdestvensky named 1966 next Probactrosaurus gobiensis also a second type, Probactrosaurus alashanicus; this was based on fragments. In 2002, David Bruce Norman came to the conclusion that the two species are identical.
Lü Junchang 1997 described a third species, Probactrosaurus mazongshanensis. It was subsequently found that this species is more closely related to Altirhinus and Equijubus than Probactrosaurus gobiensis.
System
Probactrosaurus is regarded as a representative of the Hadrosauroidea within the Iguanodontia. However, the relationships are unclear. As next of kin Equijubus and Protohadros apply. A study by Prieto - Marquez and Norell (2010 ) showed that Probactrosaurus is a basal Hadrosauroidea. As a sister taxon is considered a clade, on the one hand a nameless group with Protohadros and Eolambia and another unnamed clade that contains the hadrosaur, among other things includes. Below is a cladogram by Prieto - Marquez and Norell (2010):
Jinzhousaurus
Penelopognathus
Equijubus
Probactrosaurus
Eolambia
Protohadros
Bactrosaurus
Telmatosaurus
Shuangmiaosaurus
Lophorhothon
Hadrosauridae