Paleontologists have discovered the oldest navel known to science – and the first dinosaur ever discovered on a neptic bird – on 125 million years of fossils of a two-legged parrot with a beak in China.
The weak navel scar belongs to a reptile of the genus Psittacosaurus, who lived during the Cretaceous period (145 million to 66 million years ago). Scientists noticed a long, thin trail of umbilical cord scar when they exposed the fossils to a concentrated beam of laser light. The scar is a slight discrepancy in the pattern of the skin and scales above of the dinosaur abdomen and is the equivalent of a reptile to the navel of a mammal.
Unlike fetal mammals, which receive their nutrients from the placenta, bird and reptile embryos feed on a yolk sac connected to their abdomen through various blood vessels. When these embryos hatch, the yolk sac is completely absorbed into the body, leaving a linear scar on the abdomen that usually heals in a few days or weeks. But in some reptiles, such as alligators, umbilical cord scarring can continue after puberty. This discovery of a petrified navel is the first indication that dinosaurs may have had umbilical cord scars that never completely disappeared. The researchers published their findings on June 7 in the journal Biology of BMC.
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“This Psittacosaurus the specimen is perhaps the most important fossil we have to study dinosaur skin, ”said vertebrate paleontologist Phil Bell, a senior lecturer at the School of Environmental and Rural Sciences at the University of New England in Armidale, Australia. said in a statement. “But this continues to bring surprises that we can bring to life with new technologies such as laser imaging.”
The fossil, known as SMF R 4970, is a Psittacosaurus mongoliensisearly type ceratopsian, a group of herbivores with a beak that later included Triceratops. Measuring 6 feet (1.8 meters) long and 4 feet (1.2 m) high, P. mongoliensis he was probably a strong social creature, living in groups and looking for seeds to grind and nuts to crack in his sharp beak. Discovered about 20 years ago, the fossils of the horned-cheeked creature are remarkably well-preserved, which has allowed scientists to document individual scales, tail bristles and the first dinosaur hole discovered (described at the time as “perfect” and “unique”), Live Science reported earlier.
Researchers were able to make detailed observations of the specimen’s abdomen because of its exquisite preservation and because of the animal’s position in death – the creature petrified while lying on its back. This posture of dinosaur deaths allowed the study’s authors to apply a technique called laser-stimulated fluorescence (LSF) to the ancient reptile’s abdomen. The glow of a laser beam on the specimen caused it to emit a very faint glow, which helped scientists analyze the preserved skin on its abdomen a rock at a time. Their investigation revealed a 4-inch (10-centimeter) scar that did not appear to be caused by physical trauma or illness.
“Using LSF images, we identified distinctive scales that surrounded a long umbilical cord in Psittacosaurus an instance similar to [scars in] some living lizards and crocodiles, “said paleontologist Michael Pitman, an assistant professor at the School of Natural Sciences at the Chinese University of Hong Kong. This specimen is the first dinosaur fossil to preserve the navel, due to its exceptional state of preservation. “
Scientists estimate the age of the dinosaur by comparing the length of its femur with those of others Psittacosaurus specimens and found to be about 6 or 7 years old – approaching sexual maturity. This revealed that the navel was preserved in the early stages of the creature’s life, as are the case with modern alligators.
While the fossil specimen offers rare information on the biology of dinosaurs, it is also the subject of fierce controversy over repatriation. Discovered by an unknown region of China sometime in the 1980s or 1990s, it is said to have been smuggled out of the country and into European underground markets before being purchased and exhibited in 2001 at the Zenkenberg Museum in Frankfurt, Germany. , according to Nature (opens in a new tab). Attempts have been made to repatriate fossils in China by Chinese and European researchers, researchers said in 2001 in the journal Nature. (opens in a new tab)but ownership of the fossil is still disputed.
“The debate over the legal ownership of this specimen continues and efforts to repatriate it to China have been unsuccessful. “Our international team of Australian, Belgian, British, Chinese and American members looks forward to and supports a friendly solution to this ongoing debate,” the researchers wrote in their paper. “We believe it is important to note that the specimen was acquired by the Zenkenberg Museum in order to prevent its sale into private hands and to ensure its availability for scientific research.
Originally published in Live Science.