Mamenchisaurus

*Mamenchisaurus constructus*

* Jurassic Park Institute Artwork
* Stan Winston Artwork
* Robert F Walters Artwork

*Mamenchisaurus* is an extinct genus of sauropod dinosaur including several species, known for their remarkably long necks of around 14 metres; which made up half the total body length.

## Discoveries

It is known from numerous species which ranged in time from 160 to 145 million years ago, from the Oxfordian to Tithonian ages of the late Jurassic Period of China, and the largest species may have reached 35 meters (115 feet) in length and possibly weighed 50 to 75 tons. It is in the Mamenchisauridae.

*Mamenchisaurus* was first discovered in 1952 on the construction site of the Yitang Highway in Sichuan, China. The partial skeleton fossil was then studied, and named *Mamenchisaurus constructus* in 1954, by the renowned Chinese paleontologist Professor C. C. Young. The type specimen had an incomplete neck with 14 vertebra preserved and none of these were complete. *M. constructus* has been estimated around 13 m (43 ft) and 15 m (49 ft) in length.

    In 1972, a second species was described, named *Mamenchisaurus hochuanensis*, with a neck that reached up to 9.3 m (31 ft) in length. This species had a complete neck preserved which contained 19 vertebrae This was the longest neck known until the description of *Supersaurus*, based on a single neck vertebra, BYU 9024, with an estimated neck length of about 14 meters (46 feet). Another long-necked sauropod exceeding *M. hochuanensi*s was Sauroposeidon which was discovered in 1994. Based on the *Sauroposeidon* holotype, which only preserved 4 neck vertebra, its neck was estimated to be between 11.25 and 12 meters (36.9–39.4 feet) long.

In 1993, *M. sinocanadorum* was described, which consisted of skull material and the first four cervical vertebrae. This species possessed the longest cervical rib of any described sauropod dinosaur, measuring 4.1 meters (13.5 feet). This is longer than the longest *Sauroposeidon* cervical rib, which measures 3.42 meters (11.2 feet).[9] Additional remains attributed to this species, but not yet formally described, belong to one of the largest dinosaurs known—the restored skeleton measuring 35 metres (115 feet) in length with a neck measuring nearly 17 metres (56 feet) long.

In 2001, another *M. hochuanensis* specimen was described. It had skull, pectoral girdle and forelimb material preserved, all of which were missing from the holotype. It was also found with four fused tail vertebra, which have expanded neural arches and taller neural spines, that belong at the tip of the tail. It’s thought that these could be a weapon, such as a tail club, or a sensory organ. Other Chinese sauropods, *Shunosaurus* and *Omeisaurus*, are also known to have had ’tail clubs’ but they differ in shape to that of *M. hochuanensis*.

## Naming

*Mamenchisaurus* means 'Mamenchi lizard', from the Chinese Pinyin mǎ (马 'horse') and mén (门 'gate'), while chi is a transliteration of xī (溪 'stream' or 'brook'), combined with the suffix -saurus (from Greek sauros meaning 'lizard').

It was intended to name the reptile after the place where its fossil was first found — a construction site next to the Mǎmíngxī (马鸣溪) Ferry Crossing by the Jinsha River (金沙江, the westernmost major headwater stream of the Yangtze River), near Yibin (宜宾) in Sichuan Province of China. However, due to an accentual mix-up by Young, the location name Mǎmíngxī (马鸣溪 'horse-neighing brook') was mistaken as Mǎménxī (马门溪 'horse-gate brook').

## Species

* *M. anuyensis*: It grew Approximately 21 meters (69 feet) in length. Known from both the Suining Formation and Penglaizhen Formation.
* *M. constructus*: (Type species) The holotype specimen, represented by a partial skeleton that was 13 meters (43 feet) long.
* *M. hochuanensis*: Four partial skeletons. Known from Shaximiao Formation and 22 meters (72 feet) in length.
* *M. jingyanensis*: It is Known from Shaximiao Formation and estimated between 20 to 26 metres (66 to 85 feet) in length.

## JPInstitute.com Description

Mamenchisaurus is one of the most unique long-necked dinosaurs for a very good reason - it has a really long neck. In fact, it had the longest neck of any creature that ever lived. Stretching 46 feet (15 m), the neck on Mamenchisaurus was longer than a school bus! The rest of it was just like other members of its family; a long tail, stout legs and really big.

The architecture of the neck of this dinosaur is incredible. It had 19 neck vertebrae, more than any other dinosaur. The vertebrae had long struts running between them that would have limited the ability of Mamenchisaurus to turn its neck too sharply, but it could still reach well up into the trees to feed. This plant-eater had spatula-shaped teeth that seem to have been well designed to chew coarse plant material. This is one feature that makes it different from the members of the Diplodocidae family, which had peg shaped teeth, to which it has been thought to belong. It is now being thought of as possibly part of a group of sauropods unique to Asia. Most of the big Asian sauropods, such as Omeisaurus, had spatulate teeth. In fact, the Asian sauropods, including Mamenchisaurus, seem to share more characteristics with Brachiosaurus than with Diploducus. For evidence of this, one needs to look no further than the nose - Mamenchisaurus and other Asian sauropods are very close in evolutionary terms to that of Brachiosaurus. It is also thought that another aspect that these creatures had in common was that they were finding their food high off the ground. Diploducus and Apatosaurus on the other hand were likely feeding on low growing plants.

Note: Many people don't realize that China is one of the most prolific areas for the discovery of dinosaurs. The Sichuan Province is perhaps the best place in the world to find Jurassic dinosaurs.

## Dinosaur Field Guide Description

Mamenchisaurus ("lizard from Mamen's Brook") is basically a giant neck attached to a small body. The neck is about 40 feet (12 m) long, and the body is about the same length! The purpose of this short, wide body is to act as a stable, heavy base to anchor the neck. At the end of the neck is a short head with thick teeth. Its length allowed Mamenchisaurus to eat the leafy parts at the tops of some Jurassic trees. By doing so, it did not have to compete with its own young, who had to eat plants closer to the ground. Functionally, this dinosaur could be called a "plant vacuum." Its super-long neck allowed it to suck up hundreds of pounds of leaves from treetops. Structurally, the neck represents the pinnacle of animal engineering. The vertebrae have hollow portions where there is little internal stress on the bones. This lightens the bones and makes them stronger. Struts and braces give added strength for load bearing. On top of the neck vertebrae are split spines that form a V-shaped trough. Inside this trough lies a series of ligaments that function like the cables on suspension bridges, holding up the neck.

### Fun Facts

This dinosaur had the longest neck in the history of Earth.

### Trivia

Answer: In the book by Michael Crichton, it is a Diplodocus, but in the movie it looks more like a Mamenchisaurus.

## Links

http://web.archive.org/web/20040214062143fw\_/http://www.jpinstitute.com/dinopedia/dinocards/dc\_mamen.html#