| Analong | |
|---|---|
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Family: | †Mamenchisauridae |
| Genus: | †Analong Renet al.2020 |
| Type species | |
| †Analong chuanjieensis Renet al. 2020 | |
Analong is anextinctgenus ofmamenchisauridsauropod from theChuanjie Formation inYunnan,China. Thetype and only species isAnalong chuanjieensis.[1]
The fossils ofAnalong has a relatively convoluted history. The skeletons of two giant sauropods were discovered in 1995 by Tao Wang, who was working with theLufeng Dinosaur Museum. The fossils were found in the village of A'na and the town ofChuanjie in theLufeng County ofYunnan. The local villagers built a small shelter around the fossils because they could not be immediately excavated. They remained in situ for several years until 2000, when the two skeletons were described and given the nameChuanjiesaurus.[2] One of these skeletons, given the specimen number Lfch 1001, was made theholotype of this new genus,[3] and the other skeleton, given the specimen number LFGT LCD9701-1, was referred to the same genus and species. In 2008, theLufeng World Dinosaur Valley exhibition was built around the skeletons. In 2011, the holotype and referred specimens ofChuanjiesaurus were given a full osteological description, which included an emended diagnosis for the genus and species. LFGT LCD9701-1 was reaffirmed as the same taxon as the holotype based on the anatomy of the caudal vertebrae.[2]
In 2020, LFGT LCD9701-1 was re-examined by Xin-Xin Ren and colleagues. In this publication, Ren and colleagues determined that there were sufficient differences between LFGT LCD9701-1 and the holotype ofChuanjiesaurus were sufficient for them to erect a new genus and species to contain the specimen—Analong chuanjiensis. The genus name refers to the village of A'na and the suffix "-long" is a transliteration of theMandarin word for "dragon". Thespecific epithet refers to the town of Chuanjie, where the fossils were unearthed.[1]
The holotype ofAnalong is a partially complete skeleton lacking the skull. It includes 11 articulatedcervical vertebrae, 8dorsal vertebrae from the mid-posterior portion of the back, 4 or 5sacral vertebrae, the first 24caudal vertebrae with associatedchevrons, severalribs, bothpubic bones, the leftilium, a complete left forelimb, and the leftfemur.Analong can be distinguished from all other mamenchisaurids by severalautapomorphies including: transverse processes on the first ten caudals, a 45 degree angle between two processes on theulna, a metacarpal width 7% the width of theradius, and a pubis that is uniformly narrow along 40% of its distal width.Analong also has severalsynapomorphies including: bifid mid-caudal chevrons, a sub-equal length of the proximal condylar process of the ulna, and a weakly developed condyle of the anterior caudals.[1]
In their initial description ofAnalong, Ren and colleagues found it as a basally-branching member ofMamenchisauridae.[1] Subsequent authors have reaffirmed its affinities as a mamenchisaurid. A cladogram published by Moore and colleagues in 2023 illustrating the relationships of mamenchisaurids is shown below.[4]
| Mamenchisauridae |
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The only known fossils ofAnalong were unearthed from the Chuanjie Formation in Yunnan. This formation is roughy 221 m (725 ft) thick and is composed of purple and redmudstones andsiltstones interbedded with gray, green, and purple limestones. It unconformably overlies theLufeng Formation and conformably underlies theLaoluocun Formation. This constrains the formation's age to theMiddle Jurassic. Plant fossils from the area includepine andpodocarp conifers. Invertebrates are also common and include a diverse assemblage ofostracod andbivavle remains. Vertebrate fossils from the formation include fragmentary turtle remains and fish scales alongside large dinosaurs (Shidaisaurus andChuanjiesaurus) and the turtleXinjiangchelys.[3]
