Pronunciation: JIN-yun-PEL-tuh
Meaning: Jinyun shield
Author/s: Zheng et al. (2018)
Synonyms: None known
First Discovery: Zhejiang, China
Discovery Chart Position: #980
Jinyunpelta sinensis
The tail club is a highly specialized structure thought to characterize a subgroup of the ankylosaurine ankylosaurians, and prior to 2018, the oldest documented example of such a weapon in the fossil record belonged to the Campanian-aged ankylosaurine Pinacosaurus. But not anymore. Jinyunpelta smashed that record when it became the new oldest ankylosaurian known to have a well-developed tail club by some 20 million years. It's also the basalmost ankylosaurine and the first definitive and best-preserved ankylosaurid dinosaur ever found in southern China. But its teeth are just as notable.
Using a confocal laser microscope, Kubo et al. studied the dental microwear of Jinyunpelta and discovered that the upper half of the tooth crowns in the rear of the lower jaws had vertical scratch patterns, but on the bottom half, the scratch patterns were horizontal. They concluded that Jinyunpelta "adopted precise tooth occlusion and biphasal jaw movement", which basically means the teeth were aligned for maximum contact while the lower jaws moved both upwards and backwards during the "power stroke" of chewing. Such a sophisticated munching mechanism, which helped them grind tough vegetation effectively, had previously been seen only in ankylosaurid fossils from Late Cretaceous North America, but Jinyunpelta blazed a trail again as it pushed the presence of this feature way back into the "Middle" Cretaceous and moved it to Asia.
Using a confocal laser microscope, Kubo et al. studied the dental microwear of Jinyunpelta and discovered that the upper half of the tooth crowns in the rear of the lower jaws had vertical scratch patterns, but on the bottom half, the scratch patterns were horizontal. They concluded that Jinyunpelta "adopted precise tooth occlusion and biphasal jaw movement", which basically means the teeth were aligned for maximum contact while the lower jaws moved both upwards and backwards during the "power stroke" of chewing. Such a sophisticated munching mechanism, which helped them grind tough vegetation effectively, had previously been seen only in ankylosaurid fossils from Late Cretaceous North America, but Jinyunpelta blazed a trail again as it pushed the presence of this feature way back into the "Middle" Cretaceous and moved it to Asia.
(Chinese Jinyun Shield)Etymology
Jinyunpelta is derived from the Mandarin "jinyun" (in reference to Jinyun County in which the type locality is located) and the Latin "pelta" (shield).
The species epithet, sinensis, is derived from the Greek "sin" (referring to China) and the Latin "ensis" (from).
Discovery
The remains of Jinyunpelta were discovered in the Liangtoutang Formation, in a construction site at Lijin Industrial Park, Huzhen Town, Jinyun County, Zhejiang Province, China, by Mr. Meiyun Li, a local farmer, in June of 2008. More fossils were discovered at this site and others in Huzhen Town during several excavations by a joint team from the Zhejiang Museum of Natural History, Jinyun Museum and Fukui Prefectural Dinosaur Museum between 2008 and 2014.
The holotype (ZMNH M8960) is an almost complete skull and partial skeleton, including some vertebrae from the neck, back and hip, a partial tail club knob, some ribs, a right shoulder blade, a partial right hand, hip bones (left ilium and both ischia), a left thigh, skin armour and some tiny middle ear bones. The paratype (ZMNH M8963) is another partial skeleton, including an almost complete tail club, and the left shin and calf. Both ZMNH M8960 and ZMNH M8963 were discovered in the same quarry, approximately two to three meters apart.
Preparators
C. Yu and Y. Sheng of Zhejiang Museum of Natural History.
