Feces, vomit and fossilized food from inside stomachs have provided new clues into how dinosaurs rose to dominate Earth, a new study revealed on Wednesday.
Scientists have discovered plenty about dinosaurs — particularly about how they vanished off the face of the planet 66 millions years ago.
But “we know very little about their rise,” said Martin Qvarnstrom, a researcher at Sweden’s Uppsala University and the study’s lead author.
Photo: AP
Dinosaurs first appeared at least 230 million years ago, fossils have shown.
But they would not become the world’s dominant animal until the start of the Jurassic Period some 30 million years later.
What caused this ascension — and why it took so long — have long been a subject of fevered debate between scientists.
Photo: Reuters
For the new study in Nature, a European team exhaustively probed more than 500 “bromalites” — the fossilized remains of dinosaur feces, vomit and undigested food inside intestines — from sites in Poland.
“By linking the bromalites to the producers and identifying what’s in them, we can start connecting who ate whom or who ate what,” Qvarnstrom explained.
The researchers used new technology such as synchrotron microtomography to build a 3D image of the samples. This revealed that the excrement contained the remains of insects, plants, fish and bigger animals.
The researchers compared this with data about fossils, plants and the climate to construct a model for the step-by-step rise of the dinosaurs.
‘OPPORTUNISTIC ANIMAL’
This ascension was illustrated by the bromalites themselves, which tripled in average length and width over the 30 million-year period.
This demonstrated how the animals that digested, vomited or excreted these remains tripled in size over that time.
Some of the fossilized remains belonged to an early ancestor of dinosaurs, the Silesaurus.
Far from the mighty T-Rex, the “pretty small” Silesaurus weighed around 15 kilograms at most, Qvarnstrom said.
The dominant animal at the time were barrel-chested herbivorous reptiles called Dicynodonts, which weighed a few tons.
But Silesaurus had a big advantage over its stocky rival — it was omnivorous.
“What we see from its droppings is that it was eating a lot of insects, fish and plants,” Qvarnstrom said.
This meant the “opportunistic animal” was better at adapting to sudden changes in the environment.
For example, a massively rainy period called the Carnian Pluvial Episode lead to the evolution of many new plants. The big herbivorous reptiles struggled to adapt to this new diet. But the Silesaurus — and later long-necked dinosaurs that were ancestors of the Diplodocus — “were able to just feast on all these new plants,” Qvarnstrom said.
As the smaller dinosaurs grew bigger from this new grub, so did larger carnivores that fed on them.
By the time the Jurassic period rolled around, the landscape was dominated by giant plant-eating dinosaurs and ferocious carnivores.
COMPETING THEORIES
The study will not settle the debate about what led to the rule of dinosaurs once and for all.
There are two main theories for their rise. One is that early dinosaurs used key physiological advantages — such as standing upright — to outcompete their rivals. The other is that environmental upheaval, such as volcanic eruptions or a changing climate, killed off many of the previously dominant animals, creating an opening at the top.
The researchers behind the bromalites study suggested it was a combination of the two theories, in which the dinosaurs used their evolutionary advantages to capitalize on environmental changes that had knocked back their rivals.
Lawrence Tanner, a researcher at Le Moyne College in New York, said the study “should be seen as a starting point for further work.”
Although its methodology is “particularly creative,” the study is “limited in its context and scope,” Tanner commented in an attached Nature paper.
The research only covers the Polish Basin region, which at the time was part of the north of the Pangea supercontinent, he observed.
Qvarnstrom agreed, saying that he thought it would be “really cool” to use the model the team developed on other regions — such as the south of Pangea, where the first dinosaurs appeared.
That US assistance was a model for Taiwan’s spectacular development success was early recognized by policymakers and analysts. In a report to the US Congress for the fiscal year 1962, former President John F. Kennedy noted Taiwan’s “rapid economic growth,” was “producing a substantial net gain in living.” Kennedy had a stake in Taiwan’s achievements and the US’ official development assistance (ODA) in general: In September 1961, his entreaty to make the 1960s a “decade of development,” and an accompanying proposal for dedicated legislation to this end, had been formalized by congressional passage of the Foreign Assistance Act. Two
March 31 to April 6 On May 13, 1950, National Taiwan University Hospital otolaryngologist Su You-peng (蘇友鵬) was summoned to the director’s office. He thought someone had complained about him practicing the violin at night, but when he entered the room, he knew something was terribly wrong. He saw several burly men who appeared to be government secret agents, and three other resident doctors: internist Hsu Chiang (許強), dermatologist Hu Pao-chen (胡寶珍) and ophthalmologist Hu Hsin-lin (胡鑫麟). They were handcuffed, herded onto two jeeps and taken to the Secrecy Bureau (保密局) for questioning. Su was still in his doctor’s robes at
Last week the Democratic Progressive Party (DPP) said that the budget cuts voted for by the China-aligned parties in the legislature, are intended to force the DPP to hike electricity rates. The public would then blame it for the rate hike. It’s fairly clear that the first part of that is correct. Slashing the budget of state-run Taiwan Power Co (Taipower, 台電) is a move intended to cause discontent with the DPP when electricity rates go up. Taipower’s debt, NT$422.9 billion (US$12.78 billion), is one of the numerous permanent crises created by the nation’s construction-industrial state and the developmentalist mentality it
Experts say that the devastating earthquake in Myanmar on Friday was likely the strongest to hit the country in decades, with disaster modeling suggesting thousands could be dead. Automatic assessments from the US Geological Survey (USGS) said the shallow 7.7-magnitude quake northwest of the central Myanmar city of Sagaing triggered a red alert for shaking-related fatalities and economic losses. “High casualties and extensive damage are probable and the disaster is likely widespread,” it said, locating the epicentre near the central Myanmar city of Mandalay, home to more than a million people. Myanmar’s ruling junta said on Saturday morning that the number killed had