Titanosaurs may have been the largest dinosaurs ever to walk the Earth, but new evidence shows that they started small and were basically forced to fend for themselves almost immediately after hatching, according to a new study published Friday in the journal Science.

Kristina Curry Rogers, a paleontologist at Macalester College in Minnesota, and her colleagues found fossils from a baby Rapetosaurus in an ancient 70- to 66-million-year-old rock formation in Madagascar. The specimen, which died (probably of starvation) 39 to 77 days after birth, was found to already have adult-sized proportions and was 14 inches (35 cm) tall at the hip.

Their research suggests that the newborn Rapetosaurus likely would have had a far greater range of movement than an adult member of the species, and the findings support a hypothesis that this type of gigantic dinosaur would have been able to move independently at a very early age, unlike contemporary dinosaurs such as theropods and ornithischians, which required parental care.

“Until now, we haven’t been able to access the earliest record of life for any sauropod dinosaur. This few-week-old baby skeleton tells us a great deal about the growth and early life of newborn sauropods like Rapetosaurus,” Curry Rogers explained in a statement Thursday.

Findings helped in development of a new guidebook

Curry Rogers, who originally named the long-necked, armored, herbivorous Rapetosaurus back in 2001, told National Geographic that she and her fellow researchers found the baby titanosaur fossil while sifting through turtle and crocodile bones from the Madagascar rock formation. This fortuitous discovery presented them with a rare opportunity to study early dinosaur life.

“Our record of the earliest lives of sauropods up to this point has been limited” to a handful of embryos still in the egg and a few juvenile specimens, limiting their ability to learn more about how titanosaurs lived during this part of their lives, she told the publication. Thus, she said that her team “wanted to glean everything we could from these bones, from anatomy and body size estimates to details of bones under the microscope and with micro-CT scanning.”

Through this analysis, they were able to learn that the baby Rapetosaurus likely weighed little more than 7.5 pounds (3.4 kg) at birth, but less than three months later, had grown to nearly 88 pounds (40 kg) when it died. Furthermore, the similarity of its bones to those in adults, and the apparent signs of bone remodeling under stress, indicates that the infant dinosaur was essentially on its own, moving around independently and without parental care shortly after hatching.

The bones, which included a thigh bone, a shin and arm bone, also revealed that the dinosaur was most likely born in a drought-stricken region, which the authors believe may have contributed to its eventual demise. Curry Rogers and her colleagues have used their research to develop a guide for other scientists to help determine if a specific dinosaur species was independent at birth, or if it spend an extended amount of time being cared for by its parents.

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Image credit: Wikimedia Commons

The full and horrifying extent of coral bleaching on the Great Barrier Reef has been revealed by Australian scientists.

Aerial and underwater surveys have shown that only 7 percent of the almost 1500 mile long Reef is unaffected, and climate change is to blame.

“We’ve never seen anything like this scale of bleaching before. In the northern Great Barrier Reef, it’s like 10 cyclones have come ashore all at once,” says Professor Terry Hughes, convenor of the National Coral Bleaching Taskforce that is documenting and studying the event. “Towards the southern end, most of the reefs have minor to moderate bleaching and should soon recover.”

He added: “We have now flown over 911 individual reefs in a helicopter and light plane, to map out the extent and severity of bleaching along the full 2300km length of the Great Barrier Reef. Of all the reefs we surveyed, only 7 percent (68 reefs) have escaped bleaching entirely. At the other end of the spectrum, between 60 and 100 percent of corals are severely bleached on 316 reefs, nearly all in the northern half of the Reef.”

Why does climate change cause bleaching?

Bleaching is due to the demise of zooxanthellae – tiny, colourful marine algae that creates much of the beautiful color in coral reefs, as well as providing them with energy.

Increasingly high sea surface temperatures leads to the death of zooxanthellae, without which coral tissue becomes transparent, revealing the white coral skeleton underneath. Zooxanthellae can return if conditions revert back to something more habitable, but if temperatures continue to increase then the corals can die.

Experts in Australia graded parts of the Reef as having very severe, moderate, or little damage.

“The bleaching is extreme in the 1000km region north of Port Douglas (Cairns in Queensland) all the way up to the northern Torres Strait between Australia and Papua New Guinea,” said Prof. Andrew Baird from the ARC Centre of Excellence for Coral Reef Studies.

“Tragically, this is the most remote part of the Reef, and its remoteness has protected it from most human pressures but not climate change. North of Port Douglas, we’re already measuring an average of close to 50 percent mortality of bleached corals. At some reefs, the final death toll is likely to exceed 90 percent. When bleaching is this severe it affects almost all coral species, including old, slow-growing corals that once lost will take decades or longer to return.”

There have been three mass bleaching events in recent times – in 2016, 2002 and 1998.

“In each case, the location of the most severe bleaching coincides with where the hottest water sits for the longest period,” said Hughes.

“This time, the southern third of the Great Barrier Reef was fortunately cooled down late in summer by a period of cloudy weather caused by ex-cyclone Winston, after it passed over Fiji and came to us as a rain depression. The 2016 footprint could have been much worse,” he added.

The Great Barrier Reef is extremely important for tourism in the region, and Daniel Gschwind, Chief Executive of the Queensland Tourism Industry Council, mixed caution with optimism in saying that: “Thankfully, many parts of the reef are still in excellent shape, but we can’t just ignore coral bleaching and hope for a swift recovery. Short-term development policies have to be weighed up against long-term environmental damage, including impacts on the reef from climate change.”

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Image credit: Thinkstock