Massospondylus (longer vertebra)
Massospondylus (longer vertebra)
Named By : Richard Owen - 1854
Diet : Herbivore / Possibly Omnivore
Size : Estimated 4 – 6 meters long
Type of Dinosaur : Sauropod
Type Species : M. carinatus (type), M. kaalae
Found in : Lesotho - Upper Elliot Formation, South Africa - Clarens Formation, Upper Elliot Formation, and Zimbabwe - Forest Sandstone Formation, Mpandi Formation, Upper Karroo Sandstone Formation
When it Lived : Early Jurassic, 208-204 million years ago
Massospondylus is a genus sauropodomorph dinosaur that dates back to the Early Jurassic Period (Hettangian and Pliensbachian ages ca. 200-183 million year ago. Sir Richard Owen, who discovered remains in South Africa in 1854, described it and named it one of the first dinosaurs. Fossils were also found in Lesotho and Zimbabwe. At different times, material from Arizona’s Kayenta Formation and Argentina were assigned to this genus. However, the Arizonan- and Argentinian materials are now assigned to other genera.
M. carinatus is the type species. Seven other species have been identified over the last 150 years but M. kaalae is still valid. Many scientists are unsure where Massospondylus is on the dinosaur evolutionary tree. Although the name Massospondylidae was originally given to the genus, current knowledge about early sauropodomorph relationships has been in flux. It is not clear which other dinosaurs, if any, belong in the natural grouping massospondylids. However, several papers from 2007 support this family’s validity.
Massospondylus had been long thought to be quadrupedal. However, a 2007 study revealed that it was bipedal. Although it was likely to be a plant-eater (herbivore), early sauropodomorphs might have been omnivorous. The animal measured 4-6m (13-20ft) in length and had a long tail and neck. It also had a small head and a slender body. It had a thumb claw on each forefeet that it used to feed or defend. Recent research has shown that Massospondylus grew steadily over its lifetime, had air sacs similar in size to birds and cared for its young.
Sir Richard Owen, a paleontologist, described the first massospondylus fossils in 1854. Owen initially did not consider these fossils to be dinosaurs. Instead, Owen attributed them to “large extinct, carnivorous snakes” that were closely related to today’s chameleons, lizards, and iguanas. The material, which consists of 56 bones, was discovered in 1853 by Joseph Millard Orpen, a government surveyor, in the Upper Elliot Formation in Harrismith, South Africa. It was then donated to the Hunterian Museum, Royal College of Surgeons, London. The remains included vertebrae from the neck and back, tail, a shoulder blade, a partial pelvis, a hip, a femur, a tibia, and bones of the hands, feet, as well as vertebrae. It was difficult to identify if the bones belonged to one species or all of them were disarticulated. Owen was able distinguish three types of caudal verbrae. He attributed them to three genera: Pachyspondylus/Leptospondylus, Massospondylus. Massospondylus was distinguished from the other genera based on its longer caudal vertebrae. Owen explained that this is because the vertebrae of Massospondylus are longer than those of Macrospondylus, an extinct Crocodile. Later, however, it was revealed that the massospondylus’s caudal vertebrae were actually cervical vertebrae. All the material is likely to belong to one species. The Hunterian Museum was destroyed by a German bomb on May 10, 1941. Only casts remained. The plaster casts of the type fossils lost were insufficient to correctly diagnose a genus or species using modern taxonomic practices. Yates and Barrett (2010) designated BP/1/4934, a skull, and a largely complete postcranial skeleton at the Bernard Price Institute for Palaeontological Research as the neotype specimen.
Massospondylus remains were found in the Upper Elliot Formation and the Clarens Formation. The remains include at least 80 partial skulls and four skulls. These represent both children and adults. Based on a 1985 skull, the report Massospondylus of Arizona’s Kayenta Formation was based. The Kayenta skull is 25% larger than any African specimen. The Kayenta specimen has four teeth in its premaxilla, and sixteen in its maxilla. It also had tiny, 0.04 in-long palatal teeth, which is a first among dinosaurs. However, a 2004 restudy on African Massospondylus skulls revealed that the Kayenta specimen was not related to Massospondylus. The Kayenta skull, along with its associated postcranial elements, were identified as MCZ 8893 in 2004. They were then referred to the new genus Sarahsaurus.
Massospondylus was also reported from Argentina. However, this genus has been reassessed and reaffirmed as closely related but distinct. These fossils contained several partial skulls and skeletons, which were found in the Lower Jurassic Canon del Colorado Formation, San Juan, Argentina. In 2009, this material was named Adeopapposaurus. In 2019, a South African specimen, BP/1/4779 was made the holotype for the new genus Ngwevu and the species Ngwevu.