Sonorasaurus thompsoni was a sauropod dinosaur of the Brachiosauridae family that lived from the Early to Late Cretaceous period, 93-112 million years ago. The fact that Sonorasaurus belonged to the Cretaceous period is a challenge to the earlier concept that sauropods in North America never made it past the Jurassic Age. For instance, one of the most well-known brachiosaurs, the Brachiosaurus, also belonged to the Jurassic Age.
The name 'Sonorasaurus' translates to 'Sonora lizard'. This name is an indication of the location from where its fossils were found, in the Sonoran Desert of Arizona. Sonorasaurus is currently Arizona's official state dinosaur. Sonorasaurus was formally named by Ronald Paul Ratkevich in 1998. This dinosaur is the only member of its genus. The bones of Sonorasaurus that were found in the desert have helped researchers deduce some of its attributes. For instance, the Sonorasaurus length was about 49 ft (15 m). It probably had a weight of around 35 ton (31751.5 kg). This dinosaur had spoon-like teeth, which aided in its feeding habits. Being a herbivore, Sonorasaurus ate different plants. Facts related to its exact reproductive and social habits are still not known, and access to further fossil remains will certainly aid researchers in finding more relevant information.
The name 'Sonorasaurus' is pronounced as 'So-nor-ah-sore-us'. The name was given by paleontologist Ronald Paul Ratkevich in 1998.
Sonorasarus was a sauropod dinosaur, further classified into a brachiosaurid. This dinosaur was a member of the Brachiosauridae family.
The temporal range of Sonorasarus corresponds to the years of the Early to Late Cretaceous. This dinosaur existed 93-112 million years ago. More precisely, it was alive from the Albian to the Cenomanian stages, starting from the Early Cretaceous and ending in the Late Cretaceous.
Due to the lack of fossil remains proving otherwise, it can be assumed that Sonorasaurus became extinct towards the end of the Cenomanian stage of the Late Cretaceous.
The Sonorasaurus location was in the Sonoran Desert, located in the state of southern Arizona, southeast of Tucson. More precisely, the fossils of this dinosaur, which later came to be Arizona's official state dinosaur, were found in the Turney Ranch Formation of the Sonoran Desert. Apart from Sonorasaurus, Arizona and Tucson were home to other dinosaurs like Ammosaurus, Syntarsus, and so on. The name 'Sonorasaurus', given by Ronald Paul Ratkevich, is an indication of its place of discovery, as it translates to 'Sonora lizard'. The discovery of the fossils of this animal was made by a geology student named Richard Thompson in 1994. So, what do you think? You might as well stumble on a fossil if you are on the search!
The habitat of Sonorasaurus was characterized by semi-arid conditions that gave rise to evergreen woodlands. The rainfall in this region was variable, and further research is required to assess the exact precipitation levels throughout the year. The flora in this region of Arizona state consisted of conifers and pines.
Sonorasaurus thompsoni may have been a solitary animal. This is because another member of this family, Brachiosaurus (belonging to Late Jurassic), is thought to have been solitary, as well. However, the discovery of more fossils would give researchers a better idea about the social structure of this species.
Though the exact lifespan of Sonorasaurus is not known, this dinosaur probably lived up to 30 or more, a similar life range to other members of the Brachiosauridae family.
Sonorasaurus was oviparous, so reproduction took place through eggs. However, the exact number of eggs laid by this dinosaur has not yet been found due to a lack of fossil specimens. In general, it is known that sauropods lay between 15-40 eggs. Once the baby dinosaurs hatched out, they would grow exponentially, even after crossing the age of sexual maturity.
All the physical traits of the Sonorasaurus dinosaur, the official state dinosaur belonging to Arizona State, are yet to be established since scientists do not have access to a complete skeleton. However, the remains of Sonorasaurus discovered to date have certainly shed some light on its physical attributes.
Being a member of the Brachiosauridae family, Sonorasaurus had some characteristics typical to this group. This dinosaur had a long neck and quite a giant body. There were four pillar-like legs that provided support to the overall frame of the body. However, in comparison to other brachiosaurid, Sonorasaurus was comparatively smaller. Apart from all this, the skull fossil of this dinosaur that was recovered showed that it had a nasal opening placed at the top of its head. In addition, it had the typical brachiosaurid spoon-like teeth in its jaws.
A complete skeleton of Sonorasaurus has not been unearthed, and hence, researchers have not been able to calculate the exact number of bones this animal possessed. However, the bones that have been found to date include parts of the shoulder blade, limb joints, and ribs. Nevertheless, these partial remains have helped paleontologists deduce various aspects about this dinosaur.
Even though the patterns of communication used by the Sonorasaurus remain a mystery, since this dinosaur was a brachiosaur, it can be assumed it communicated using methods that are similar to the other members of its group. In general, brachiosaurs are known to have communicated through vocal and visual means, with the help of various calls and bodily movements.
Despite being a brachiosaurid, Sonorasaurus was not very large in size. This dinosaur had a length of 49 ft (15 m) and a height of 26 ft (8 m). When compared to the related Brachiosaurus, which had a length range of 59-69 ft (18-21 m), it is quite clear that Sonorasaurus was significantly smaller.
The exact speed of Sonorasaurus is yet to be ascertained. However, dinosaurs belonging to the same family as Sonorasaurus showed moderate to high speeds while running. For instance, the mighty Brachiosaurus had a speed of about 10 mph (16 kph). Since Sonorasaurus was smaller, its speed probably varied a bit in comparison to that of Brachiosaurus'.
The weight of Sonorasaurus, the official state dinosaur of Arizona, is thought to have been somewhere around 35 ton (31751.5 kg). This dinosaur is often compared to a small herd of elephants due to its enormous size.
The male and female Sonorasaurus have no species names assigned to them. They are simply referred to as male Sonorasaurus and female Sonorasaurus.
A baby Sonorasaurus would be known as a hatchling.
Like other brachiosaurid dinosaurs, the Sonorasaurus was also herbivorous in nature. It relied on the various plants and the dominant flora in its environment to sustain its diet. Sonorasaurus had species spoon-like teeth, which aided the dinosaur in consuming plants that are tough in nature. Interestingly, this dinosaur, along with other brachiosaurs, resorted to slicing through their food instead of pulling it off from the branches.
Since Sonorasaurus was a herbivorous animal, it can be safely assumed that it was not aggressive.
This dinosaur was given the specific epithet of 'Thompsoni' after Richard Thompson, who found the remains of this dinosaur.
Sonorasaurus was discovered by Richard Thompson, a student of geology, in the year 1994. This event took place in the Sonoran Desert, part of southern Arizona. Following this discovery, Thompson reported to the paleontologist Ronald Paul Ratkevich, who continued further investigations to secure more fossils. The entire process came to an end in 1999. However, a year earlier, in 1998, Ratkevich successfully described and named this new dinosaur. Exactly 20 years later, in 2018, Sonorasaurus became the official state dinosaur of Arizona.
While a lot of unique features are related to Sonorasaurus, the unique feature is probably the fact that this dinosaur lived during the Cretaceous period. This is because earlier research suggested that sauropods, the clade to which brachiosaurs belong, were extinct in North America before the start of the Cretaceous period, during the Jurassic. However, the presence of Sonorasaurus confirms that sauropods did exist during the Cretaceous era as well, even if they were not as common.
*The first image is by Dmitry Bogdanov.
*The second image is by Mproart.