Thinking of discovering tiny dinosaurs, who would have thought that when they grow up they weigh a ton

In the 1970s, Argentine paleontologist Jose Bonaparte led a research team that discovered eight dinosaur fossils in Laguna-Colorado, Santa Cruz, Argentina, and around two dinosaur fossils. Another specimen is an egg and some eggshell fragments. These fossils come from the Colorada Formation of the Triassic – about 215 million years ago, they were one of the earliest dinosaurs. For various reasons, it was not until 1990 that paleontologists established the genus Mussaurus based on these fossils, and the species was named Mussaurus patagonicus.

Based on the structure of the pelvis and fossil genera, paleontologists speculate that Mussaurus was a prosauropod dinosaur (a family of sauropod dinosaurs in Plateosauria. Plateosauridae is one of the dinosaur families). the first suborder Sauropodomorpha to exist in Asia, Europe and South America).

Mussaurus fossils ranged in length from 20 to 37 centimeters and were the smallest dinosaur fossils found at the time. Some people mistakenly believe that these Mussaurus fossils come from adults, and believe that Mussaurus is the smallest dinosaur ever discovered. As research continued, paleontologists determined that the adult Mussaurus could grow up to several meters long and was a medium-sized dinosaur. Although Mussaurus was not the smallest dinosaur, its fossils provided valuable information for early studies of sauropod growth patterns.

In 2007, paleontologists discovered more fossils in the Colorado Formation, where Mussaurus was found, including at least 14 juvenile Mussaurus fossils. However, compared to previous findings, the newly discovered Mussaurus fossil is 4 times the size of the newly hatched small dinosaurs, but they are still in the early stages of skeleton development.

Studies have shown that the maturation process of Mussaurus developed faster in the early stages, faster than other ancient protosauropods. In terms of skeletal histology, Mussaurus is also more closely related to sauropod dinosaurs than Banosaurus and Ceratosaurus.

In addition, according to the researchers, a newborn Mussaurus patagonicus, when hatched, weighs only about 60 grams and can fit in the palm of an adult. During this time their head and neck are relatively large, the legs are developed so that they can move evenly on all four legs. However, as their size increases, the tail has uneven growth, which causes the center of gravity of the body mass to shift to the pelvic region and help this species to stand up on two legs.

In fact, when considering a dinosaur could really stand on two legs, the length of the tail and the neck would be the most important thing, not the balance between the length of the forelegs and the hind legs.

And considering the length of the tail and neck is most important when figuring out whether dinosaurs were upright or not, which is more important than the balance between hind leg length and front leg length.

New research shows that strong growth in the first few years of life will lead to a change in the way it moves. At an adult stage, Mussaurus patagonicus is about 6 m long and weighs more than 1,000 kg.

The findings are based on 3D renderings created from fossils depicting 3 key stages of a dinosaur’s life: incubation, 1 year of age, and adulthood, then adding physical features such as a head and neck. , body, tail and limbs.

Dr Andrew Cuff, a University College London biologist, said: “We’ve struggled to find any animals other than humans going through that transition. Mussaurus goes through a string of events. special growth. They are hatched similar to a chick, but in later years they become as heavy as a rhinoceros, and then they will walk on two legs instead of four.”