Agilisaurus
From Latin 'agilis' meaning 'agile' and Greek 'sauros' meaning 'lizard', meaning 'agile lizard'.
Agilisaurus is a genus of ornithischian dinosaur from the Middle Jurassic Period of what is now eastern Asia. The only named species is A. louderbacki, recovered from the Lower Shaximiao Formation of Sichuan, China. It was about 1.2-1.7 m (3.9-5.6 ft) in length, 60 cm (2.0 ft) in hip height, and 40 kg (88 lb) in weight. It has leaf-shaped teeth that were well-adapted to its abrasive, plant-based diet. Most surprisingly, the wavy enamel of the teeth of this genus (and all other ornithopods), presumed to make them more resistant to wear, was previously thought to be exclusive to hadrosaurs. This is also the case for Changchunsaurus from the Cretaceous Period.
Diagnosis
- Middle part of parietal strongly contracted
- Nasal long with longitudinal depression at central suture
- Posterior process of premaxilla does not contact the lacrimal
- Palpebral bone well-developed, posterior end abutting lateral surface of postorbital, dividing orbit into upper and lower openings
- Elliptical foramen present on lateral surface of femoral shaft distal to fourth trochanter
- Obturator process of ischium positioned at proximal third of shaft
Species
Agilisaurus louderbacki Peng, 1992
Type species
Named for Dr. George D. Louderback, the American geologist who was the first to recognize dinosaur fossils from the Sichuan Province of China in 1915.
- Holotype
- ZDM 6011 , Zigong Dinosaur Museum
- Material
- Nearly complete skeleton lacking only portions of the left forelimb and left hindlimb
- Horizon
- lower Shaximiao Formation, Bajocian–Oxfordian, Middle Jurassic–Late Jurassic , 170.9–154.8 million years ago
- Locality
- Dashanpu, Sichuan, China
References
- Peng, G. (1992). Jurassic ornithopod Agilisaurus louderbacki (Ornithopoda: Fabrosauridae) from Zigong, Sichuan, China. Vertebrata PalAsiatica 30(1): 39-53. peng1992a