Linhevenator Temporal range: Late Cretaceous, | |
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Holotype Fossil | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Family: | † Troodontidae |
Subfamily: | † Troodontinae |
Genus: | † Linhevenator Xu et al., 2011 |
Species: | †L. tani |
Binomial name | |
†Linhevenator tani Xu et al., 2011 | |
Linhevenator is a genus of short-armed troodontid theropod dinosaur from the Late Cretaceous (Campanian) Bayan Mandahu Formation of Bayan Mandahu, Inner Mongolia, China. [1]
The type species Linhevenator tani was named and described in 2011 by Xu Xing, Tan Qingwei, Corwin Sullivan, Han Fenglu and Xiao Dong. The generic name combines a reference to the Linhe region with a Latin venator, "hunter". The specific name honours Professor Tan Lin. [1]
The holotype of Linhevenator is specimen LHV0021, a partial skeleton of an adult individual, including a cranium and mandible, six dorsal vertebrae, a right scapula, a right humerus, the ilia, a left femur and a left foot. It was found in 2009 and represents the most complete troodontid remains known from the Upper Cretaceous. Its four autapomorphies (unique traits) include a jugal with a lateral flange, a surangular crest that is anteroventrally oriented, the presence of medial expansion near the distal end of the femur, and a wide longitudinal groove present along the distal third of the dorsal surface of the third metatarsal. [1]
Linhevenator is a troodontid, a group of small, bird-like, gracile maniraptorans. All troodontids have many unique features of the skull, such as closely spaced teeth in the lower jaw, and large numbers of teeth. Troodontids have sickle-claws and raptorial hands, and some of the highest non-avian encephalization quotients, meaning they were behaviourally advanced and had keen senses. [2] Linhevenator is a rather large troodontid with an estimated body weight of 23 kg (51 lb), with a length of 1.9 to 2.7 meters (6.2 to 8.9 ft) with an average of 2.2 metres (7.2 feet), based on allometric scaling from Byronosaurus , Stenonychosaurus , and Zanabazar . The arms are relatively short but the humerus is very robust. The describers suggest the arm might have been used for digging or climbing. The first toe was preserved in a lateral position, instead of pointing forwards. Linhevenator has a dromaeosaurid-like pedal digit II, carrying a sickle-claw larger than that of basal troodontids. [1]
Linhevenator was assigned to the Troodontidae by the describers. It possesses a combination of "primitive" (basal) and derived characters, but was found to be a derived troodontid in a phylogenetic analysis, in a polytomy with Troodon and a clade formed by Zanabazar and Saurornithoides . This position was seen by the authors as an indication for an evolutionary trend in the Troodontidae of shortening the forelimbs and for a parallel evolution of large sickle-claws with both the troodontids and the dromaeosaurids. [1]