Ammosaurus ‭(‬sand lizard‭)

Short Info

Ammosaurus ‭(‬sand lizard‭)

Phonetic : ah-moh-sore-us.

Named By : Othniel Charles Marsh‭ ‬-‭ ‬1891

Diet : Herbivore

Size : Estimated 5 meters long

Type of Dinosaur : Sauropod

Type Species : A. major (‬type‭)

Found in : USA – Portland Formation

When it Lived : Early Jurassic, 195-180 million years ago

Ammosaurus (“sand Lizard”) is an genus of sauropodomorphs that was found in during the Early as well as the Middle Jurassic Period of North America. At just 4 metres (13 feet) in length, it was tiny when compared with the other suborders of it which contained the largest animal ever to walk on Earth. Gregory S. Paul estimated its weight at 70kg in the year 2010. It was a multi-faceted animal that was able to move bipedally and quadruple, and could be Omnivorous. There are remains found outside of Connecticut however, they are somewhat, if ever being referred to as Ammosaurus.

The term “generic name” Ammosaurus originates by its Greek word “ammos” (“ammos” as “sandy ground”) and “sauros” (“lizard”) which refers to the sandstone on which it was discovered and its reptile nature. There is a current legitimate kind of species (Ammosaurus major) that is called because it is bigger than Anchisaurus and was initially thought to be a separate species. Anchisaurus major. It is a well-known American paleontologist Othniel Charles Marsh created this particular designation in 1889. The year was 1891 when Marsh came up with the name of the Genus Ammosaurus to refer to this particular species. He later named another kind from Anchisaurus by 1892 as Anchisaurus solus, which was derived from a specimen of a young animal YPM 209, found in the same quarry that Ammosaurus major was discovered in. In 1932, Friedrich von Huene renamed this to Ammosaurus solus. Scientists are now able to see it as being to be a synonym for Ammosaurus major.

The relationship between Ammosaurus to other dinosaurs remain a mystery in the present. Ammosaurus is an early member in the suborder Sauropodomorpha and is the closest with Anchisaurus and could be a synonym. Different paleontologists believe Anchisaurus as a prosauropod that is either basal, or an sauropodomorph superior to prosauropods, but not part of Sauropoda specifically.

Marsh initially described Ammosaurus major in the form of Anchisaurus major, but Marsh changed the animal from its original genus two years afterward. But, recent research have indicated the possibility that Ammosaurus along with Anchisaurus are one and the same animal in the end (Sereno 1999). Others prefer keeping the two genera apart because of anatomical differences between the hind foot and pelvis however, the two species are nevertheless considered to be sister taxa. Because the specimen YPM 1883 was identified as the neotype for Anchisaurus polyzelus It is highly likely Ammosaurus is a subjective synonym of the species.

The fossils of Ammosaurus were found inside the Portland Formation of the Newark Supergroup located in the U.S. state of Connecticut. This formation has preserved an arid climate with intense dry and wet seasons that span from the Hettangian time to the Sinemurian period, roughly 200-195 million years in the past. The first specimens were retrieved from a quarry of sandstone, which was utilized to construct the South Manchester Bridge in Connecticut. Actually, the Holotype specimen, YPM 208, was discovered on 20 October 1884 , discovered from quarry employees. Unfortunately, it is only the rear part of the skeleton as the block that contained the front portion had been placed in the bridge by the time Marsh obtained the fossil. In August 1969 the bridge was torn down and some Ammosaurus remnants later identified as YPM 6282, were found by a group led through John Ostrom. Three other skeletons in a state of incompleteness from different ages are recognized from Connecticut however, there isn’t a skull to be found. Ammosaurus remains in Bajocian stages of North America, making it one of the rare “prosauropod” genera to survive through The Middle Jurassic.

Ammosaurus remains are discovered from other regions in North America, but may not be the true specific species A. major or even the genus in any way.

It is believed that the Navajo Sandstone of Arizona is identical to that of the Portland Formation, and has produced prosauropod remains which are often called Ammosaurus. It is however possible that they belong to the Genus Massospondylus that is known as a distinct species in South Africa.

The eastern Canadian Province that is Nova Scotia, scientists have discovered prosauropods from the McCoy Brook Formation, which is between 200-197 million years old. It dates back to in the Early Jurassic Hettangian stage. These Nova Scotia material provides clues to the diet of the creatures. There were a lot of gastroliths, which are stones that were swallowed to grind plant material inside the intestines located in the abdomen and bone was also found in an animal’s skull, a tiny sphenodont called Clevosaurus. This suggests that the dinosaurs were omnivores, having their diet mostly comprised of plants, but occasional meat. But, the remains have not been completely described or illustrated and were not even formally attributed to Ammosaurus. Another study has found them to be a new sauropodomorph taxon, Fendusaurus Elloni.