Tag Archives: gobi

New Hadrosauroid.

New species of duck-billed dinosaur discovered in the Gobi Desert

A fossilized, nearly-intact dinosaur skeleton unearthed in Mongolia fills a gap in the evolution of hadrosaurs.

New Hadrosauroid.

Skeletal reconstructions of Gobihadros mongoliensis.
Image credits Tsogtbaatar et al,, (2019), PLOS ONE.

Researchers from the Mongolian Academy of Science and the Royal Ontario Museum, funded by the Hayashibara Museum of Natural Sciences, describe a new species closely related to Hadrosaurids, which they named Gobihadros mongoliensis. The new species will help us better understand the evolution and ecology of the dinosaur family Hadrosauridae, the ‘duck-billed’ dinosaurs.

Quak

“The article describes, for the first time, extraordinary well-preserved fossil material of hadrosauroid dinosaur as a new genus and species from the early Late Cretaceous in Mongolia. We hope that it will be very useful material for further study of the evolution of hadrosauroids, iguanodintians and ornithopods as well,” the authors write.

Duck-billed dinosaurs were quite successful during their day in the Late Cretaceous. They had a wide geographical range over the world as it was at the time and were important large herbivores in their ecosystem. But we don’t really know much about the species during its early days. Some partial fossils found previously are helping us piece together the duck-billed dinos’ family tree, but complete fossils remain few and far between.

Gobihadros mongoliensis was discovered at the Bayshin Tsav Site in the Gobi Desert, Mongolia. Several specimens were found at the site, including one “virtually complete” skeleton measuring almost three meters in length. Anatomical comparisons to Hadrosauridae fossils revealed that this species doesn’t quite fit into the family. The species, however, are very closely related. Gobihadros is the first hadrosaur-like dinosaur from the Late Cretaceous of central Asia known from complete remains.

The team also reports, based on comparisons to later Asian hadrosaurs, that Gobihadros would not make it through the natural-selection gauntlet. Later Asian hadrosaurs are related to species in today’s North America, and likely migrated from there during the Late Cretaceous. The authors caution that we need more fossils from this transition period in order to get a proper idea of what happened — and when. But, from the data we have now, Gobihadros seems to have disappeared from Asia and was soon followed by the hadrosaurs. This suggests that the hadrosaurs ultimately outcompeted species like Gobihadros.

“[…] the relationships of other taxa are well-resolved, and in combination with biostratigraphic data, suggest that hadrosaurids from the Maastricthian of Asia migrated from North America across Beringia in the Campanian, and replaced non-hadrosaurids such as Gobihadros,” the authors conclude.

The paper “A new hadrosauroid (Dinosauria: Ornithopoda) from the Late Cretaceous Baynshire Formation of the Gobi Desert (Mongolia)” has been published in the journal PLoS ONE.

Archaeologists unearth a huge dinosaur footprint in the Gobi desert

Archaeologists have discovered one of the largest ever dinosaur footprints in the Gobi desert. The print is thought to have belonged to a titanosaur.

Professor Shinobu Ishigaki of the Okayama University of Science lies next to the footprint in the Gobi desert.
Image credits Japan Times.

The print was discovered this August in the Gobi desert by a joint Japanese-Mongolian team. Measuring in at 106cm (42in) in length and 77cm (30in) in width, according to the AFP, it’s a real monster of a fossil. The team believes the imprint was formed by a titanosaur, a giant, long-necked herbivore which could grow to be over 30 meters (98ft) long and 20 meters (66ft) tall.

The imprint was formed in a Cretaceous layer, deposited between 70 and 90 million years ago, most likely by sand rapidly filling a mold left by the dinosaur‘s passing. The team is very excited about the find, hoping that it will give insight into how titanosaurs walked — footprints have been used before to glimpse into dinosaurs’ way of life.

“This is a very rare discovery as it’s a well-preserved fossil footprint that is more than a metre long with imprints of its claws,” a statement from Okayama University of Science read, according to AFP.

The researchers from Okayama University of Science and the Mongolian Academy of Science are now searching for the dinosaur’s remains, said OkUni paleontology professor Shinobu Ishigaki for the Japan Times. The only known specimen up to now was found in Argentina in 2014. Weighing a hefty 70 tons and being 37 meters (122ft) long, it was dubbed the largest dinosaur ever discovered. A replica of the beast is on display at the American Museum of Natural History in New York.

 

Corals under attack summon friendly fish

The natural world sometimes has a magnificent way of dealing with its own problems – and this is exactly the case here. Coral threatened by toxic seaweeds emit a chemical signal which draws fish to eat away the danger.

When Acropora nasuta corals come into contact with the toxic seaweed Chlorodesmis fastigiata, they scream for help; but they don’t use sounds; instead, they emit a chemical signal that attracts the “bodyguards”: inch long gobies, fish that live in the crevices and “outskirts” of the corals. According to Mark Hay, of the Georgia Institute of Technology in Atlanta. Hay and his colleague Danielle Dixson, the gobies were summoned minutes after the threat appeared.

Working in the Fiji, they noticed a 30% drop in seaweed abundance, in only three days after the gobies were summoned. But other fishy residents of the coral reef weren’t so helpful. Damselfish had an entirely different approach, but still one conditioned by the chemical signal: when they “heard” the call, they simply abandoned their homes within 48 hour – talk about your scumbag citizen.

“The neighbourhood is going to hell, we’re out of here.” – what a damselfish probably says when it receives the signal.

“The sensory basis for ecological interactions remains enigmatic, especially in marine habitats,” says Richard Zimmer, who studies chemical signalling between organisms at the University of California, Los Angeles. “This research by Dixon and Hay bridges the gap” between cause — in this case the chemical signal — and the effect on the ecosystem.

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