High-resolution computed tomography exposed fossilized embryos of Mussaurus within some of the eggs and revealed all these fossils belong to a communal breeding site of a single dinosaur types.
“The bones of these dinosaurs grew in yearly cycles, much as the tree rings, so by counting the growth cycles we could presume the age of the dinosaur,” includes Pol.
All the findings reveal a well-organized herd structure and it is the very first record of this kind of complex social behavior in an early dinosaur (it pre-dates other records of dinosaurs with evolved social behavior by more than 40 million years). “These are not the earliest dinosaurs, however they are the oldest dinosaurs for which a herd behavior has actually been proposed. Mussaurus belongs to the very first effective household of herbivorous dinosaurs, so we postulate that being social and protecting their young together as a herd may have been part of the factor these long-necked dinosaurs were so common in all continents,” concludes Pol.
After an intricate journey from Argentina (it is not every day that somebody takes dinosaur eggs as carry-on baggage in between continents), Pol pertained to the ESRF with 30 out of the more than 100 eggs discovered on the website, to scrutinize them with powerful X-rays. “We spend 4 days scanning the eggs around the clock,” discussed Fernandez, “it was tiring, however the amazing outcomes were morale-boosting”. High-resolution computed tomography revealed fossilized embryos of Mussaurus within some of the eggs and revealed all these fossils belong to a common breeding website of a single dinosaur species.
The researchers, in parallel, studied the site itself. The fossils were found in multiple rock horizons at the same region, indicating that Mussaurus returned to the exact same area during successive seasons to form breeding colonies. Based on the sediments, the scientists had the ability to presume that the nesting ground was found on the dry margins of a lake.
Using X-ray imaging, the researchers scanned eggs to discover preserved embryo skeletons, which they used to validate the fossils as members of the plant-eating dinosaur, Mussaurus patagonicus. Credit: Vincent Fernandez
A crucial element of this locality is that dinosaur skeletons were not randomly spread throughout the fossil site, but instead they were grouped according to their age. Dinosaur infants fossils were located near the nests. 1 year old children were discovered carefully associated with each other, including a cluster of 11 skeletons in resting posture, suggesting that Mussaurus formed schools of young individuals. Adults and sub adults were frequently associated in sets or alone however all within one square kilometer location. To figure out the age of the juvenile fossils, scientists performed histological studies, i.e. cutting a thin piece of bone and observing the bone tissue under a microscopic lense. “The bones of these dinosaurs grew in yearly cycles, much as the tree rings, so by counting the development cycles we might infer the age of the dinosaur,” adds Pol.
The group of researchers utilized high-energy X-rays at the European Synchrotron (ESRF) to permeate the dinosaur eggs without ruining them and get a full view inside them. Credit: Vincent Fernandez/Diego Pol/ESRF
All the findings show a well-organized herd structure and it is the very first record of this kind of complex social habits in an early dinosaur (it pre-dates other records of dinosaurs with progressed social habits by more than 40 million years). Mussaurus belongs to the first successful household of herbivorous dinosaurs, so we postulate that being social and securing their young together as a herd might have been part of the factor these long-necked dinosaurs were so common in all continents,” concludes Pol.
Scientists Diego Pol and Vincent Fernandez throughout imaging experiments of the Mussaurus patagonicus eggs at the ESRF, the European Synchrotron, France. Credit: ESRF, the European Synchrotron
Check Out Fossil Treasure Trove Shows Complex Social Herd Behavior in Dinosaurs 193 Million Years Ago for more on this research study.
Referral: “Earliest evidence of herd-living and age segregation among dinosaurs” by Diego Pol, Adriana C. Mancuso, Roger M. H. Smith, Claudia A. Marsicano, Jahandar Ramezani, Ignacio A. Cerda, Alejandro Otero and Vincent Fernandez, 21 October 2021, Scientific Reports.DOI: 10.1038/ s41598-021-99176-1.
Artistic restoration of a Mussaurus patagonicus nest. Credit: Jorge Gonzalez
New research on a vast fossil site in Patagonia shows that a few of the earliest dinosaurs lived in herds and recommends that this habits may have been among the keys to the success of dinosaurs. The discovery, at the ESRF, of embryos of the same types inside fossilized eggs contributed to the outcomes.
In the past, research studies have actually revealed that some dinosaurs that existed in the newest stage of the dinosaur Era (the Cretaceous Period) lived in herds. However, a major pending concern was when and how this behavior appeared in their evolutionary history.
New research on a vast fossil website in Patagonia reveals that a few of the earliest dinosaurs, the Mussaurus patagonicus, lived in herds and suggests that this behavior may have been one of the secrets to the success of dinosaurs. Credit: Jorge Gonzalez
In the early 2000s, an international team of researchers discovered a 190-million-year-old dinosaur nesting ground, which likewise contained juvenile skeletons coming from Mussaurus patagonicus, a primitive, herbivorous sauropodomorph dinosaur (forerunner of the big, long-necked dinosaurs) in Patagonia (Argentina). “Such a preserved site was bound to provide us with a lot of details about how early dinosaurs lived,” described Diego Pol, the paleontologist at CONICET and who discovered the site.
One of the components that could clarify how early dinosaurs lived was the eggs discovered on the site and Pol desired to discover whether they were laid by Mussaurus or not. “It is tough to discover fossil eggs, and much more to discover fossil eggs with embryos inside, as you need extremely special conditions for their fossilization,” explains Pol. The ESRF, the European Synchrotron, is the best tool to research study this kind of samples: “We utilize high-energy X-rays to permeate in the sample without damaging it and get a complete view inside it,” stated Vincent Fernandez, paleontologist at the London Natural History Museum and former ESRF scientist.
