The heart test revealed: the dinosaur had warm blood
by Tamara Traubman
Scientists have found a fossilized heart of a dinosaur for the first time. The discovery also reveals a sensational scientific finding about the dinosaurs. Contrary to everything known to scientists so far, say the team of researchers, the dinosaur that was discovered did not have cold blood like reptiles, but warm blood.
The dinosaur, or Thesulosaurus in its scientific name, lived about 66 million years ago. He walked on two and fed on plants. The researchers, who discovered it during excavations in South Dakota, gave it the name Willow, as a tribute to the wife of the farmer on whose land the fossil was discovered. Willow belongs to the type of dinosaur that many researchers believe birds evolved from.
The man who discovered Willow, Michael Hamer, a professional dinosaur collector and one of the research partners, noticed that the dinosaur's ribs were remarkably well preserved, and thought that some internal organs might have been preserved in its chest cavity. Instead of removing all the soil and dirt around the bones, he cleaned only the surface of the fossil and sent it for computed tomography (CT) scans. The researchers were surprised to discover that scans of the dinosaur's chest cavity showed a heart with a structure more similar to that of birds and mammals than to the heart of contemporary reptiles, and from this they concluded that it had warm blood.
Willow's heart consists of four chambers and a tube-like structure, which was probably the aorta - like the hearts of birds and mammals. Not all parts of the heart were preserved - delicate parts such as the atrium of the heart probably collapsed when the dinosaur died. The research is published today in the scientific journal Science.
"This challenges some of our most fundamental theories about the evolution of dinosaurs," paleontologist Dr. Dale Russell, from the University of North Carolina, one of the partners in the study, said in an interview with Haaretz. "It's really amazing that a dinosaur probably had such a developed heart. The consequences of this completely knocked me down."
He says that in light of the new findings, it will be interesting to re-examine the dinosaur's activity. A heart with four chambers allows oxygenated blood to be delivered to the body, which gives birds and mammals a relatively fast metabolism. In contrast, reptiles tend to be slower, and their oxygen consumption is lower.
Dr. Russell says that it's very possible that other dinosaur fossils also have preserved internal organs, but the researchers just didn't notice them. "To clean a fossil for the purposes of research and display of the skeleton, everything that is not bone is thrown away. It's interesting how much material we lost in this way."
{Appeared in Haaretz newspaper, 21/4/2000{
In a quarry in northern Italy, the remains of a carnivorous dinosaur of an unknown type, 8 meters long, living in the Jurassic period 200 million years ago, were discovered
11/11/2000
News agencies
Italian palaeontologists announced Thursday that they had identified the remains of an unknown type of dinosaur. The dinosaur, which was a meat eater, lived about 200 million years ago. The remains of the dinosaur were found in the Salterio quarry, near Milan in northern Italy.
Giorgio Truzzi, the director of the paleontological department at the Historical Museum of Milan, said that according to the remains, the length of the dinosaur reached eighty meters, it weighed more than a ton, and that it had a long neck and its sharp teeth reached seven centimeters in length.
The scientists believe that the dinosaur lived in the Jurassic period and that it was related to more primitive forms of meat-eating dinosaurs. The Jurassic period lasted from 208 to 140 million years before our time. The new dinosaur was named Saltrizaurus after the quarry where it was discovered. More than a hundred fossilized bone fragments and one tooth were discovered there.
* * * ** *
Late credit ("Haaretz" 20/11/94)
A fossilized egg of a dinosaur of the species Phyloseratops obiraptor, and inside it a fossilized skeleton of a fetus, found in the Gobi Desert in Mongolia, reinforces the notion that different species of dinosaurs used to care for their offspring.
The care of the offspring is an outcome of a choice between two possible main reproductive strategies. One strategy is based on spawning very many offspring, or laying a large amount of eggs, and abandoning the eggs, or the offspring to their fate. Thus, even if some of the eggs or offspring are eaten, or destroyed for various reasons, there will still be some that will survive and carry the genetic load to the next generation.
The second strategy entails laying a few eggs, or giving birth (or spawning) to a small number of offspring, and ensuring their safety through care and protection. In a well-known sense, this is the old dilemma between quantity and quality.
The explorers of the oviraptor Philoseratops egg found to their surprise that it was very similar to fossilized eggs found nearby, in 1923, and mistakenly associated with a small vegetarian dinosaur of the Protoceratops species. Next to the eggs discovered in 1923 was also a fossilized skeleton of a dinosaur, which the researchers believed came to devour the abandoned Protoceratops eggs. Therefore, they gave this dinosaur the name Oviraptor Phyloseratops, which means "predator of protoceratops eggs".
Now it turns out that the "predator" did not come to the ferret. In fact, they were his own eggs and he kept them. However, this finding does not indicate the behavior of all dinosaur species. Different dinosaur species may have adopted different reproductive strategies.
* * ** * * **
The Age of the Gigantosaurus ("Haaretz" 24/10/94)
New York Times
A hard blow to the Tyrannosaurus Rex. Fossils recently discovered in South America have revealed the remains of an animal that may be the largest meat-eating dinosaur yet discovered, scientists reported in the latest issue of the journal. "Nature
The scientists estimate that the length of the dinosaur, which is similar to Tyrannosaurus Rex, was 13-12 meters and weighed 8-6 tons. He roamed the steppe that is now Argentina, searching for food that he chewed with his long, jagged teeth.
According to Dr. Rodolfo Correa, the author of the report and a paleontologist at the Carmen Pines Banken Museum in Argentina, the dinosaur lived about 100 million years ago, about 30 million years before the appearance of Tyrannosaurus Rex, but was a little longer and heavier. It appears to have weighed three tons more, Correa says.
The fossils were discovered by Ruben Karolini, a mechanic whose hobby was searching for dinosaur bones, and the giant dinosaur was named Gigantosaurus Karolini. The scientists discovered only about 70% of the dinosaur's skeleton. According to Kuria, without a complete skeleton one can only estimate what the exact size of the animal was. However, it is clear that the dinosaur ran on its hind legs, and most likely had small arms. It is still unclear what he feeds on in his environment, which resembles an African savannah.
Despite the general resemblance to the Tyrannosaurus rex, the Gigantosaurus was not closely related. The two animals emerged separately in different places, time and space where there were ecological niches for giant carnivores, Kuria says. Tyrannosaurus rex lived in North America, at a time when there was no land bridge from South America that could have allowed Gigantosaurus or its descendants to move north and become the ancestors of Tyrannosaurus rex.
Jack Horner, curator of paleontology at the Museum of the Rockies in Montana, says comparing the size of Gigantosaurus and Tyrannosaurus rex is dangerous because dinosaurs grew continuously until the day they died. Therefore, there is no clear answer to the question of how big Tyrannosaurus rex was, and estimates vary between 12 and 15 meters. Fossils of a meat-eating dinosaur from North America hint at the existence of another animal, larger than Tyrannosaurus rex, says Horner, but the results of the examination of these bones have not yet been published.
And in any case, more than size will be important in determining whether the Gigantosaurus was a hunter, or was content with scavenging.
The shark-toothed reptile from the Sahara ("Haaretz" 31/07/96)
Salvin Merit
Remains of dinosaur fossils recently discovered in the Sahara desert in Morocco are strikingly similar to the giant carnivorous dinosaur Tyrannosaurus rex, the huge monster that scared the viewers in "Jurassic Park", and lived about 70 million years ago in North America. The great similarity points to a common origin of the two carnivores and it indicates that Africa was not completely separated from the northern continents at that time, and the dinosaurs could migrate from place to place.
A giant dinosaur skull was the most dramatic find uncovered in the Sahara by two expeditions of paleontologists (researchers of fossils) from the University of Chicago. Until then, not much was known about the dinosaurs that lived in Africa.
Of the hundreds of species of dinosaurs identified so far around the world, only a few could probably exist in such remote and hostile regions as Africa. "We know very little about the dinosaurs that lived in Africa in the Cretaceous, the period that marked the age of the dinosaurs. Most of the evidence from this period came from North America and Asia. The fossils discovered in Morocco allow us for the first time to examine the nature of the carnivores that evolved on the isolated continent of Africa," says Paul Sarno, who headed the expeditions.
Sarno became interested in the evolution of dinosaurs in Africa in 1990 when he joined a group of paleontologists from the British Museum that went looking for fish fossils in Nigeria. "Then we discovered a burial complex of dinosaurs the size of a basketball court with huge bones buried in the sand. One of the chest bones reached a length of two meters," Serno says. The findings ignited his imagination and he decided to organize an excavation expedition to the area.
After three years of planning, he managed to lead a group of 21 scientists and students back to Nigeria. In six Land Rovers loaded with equipment, they crossed more than 2,500 kilometers of the Shakhon desert and spent two months searching for the remains of the dinosaurs that lived there. "When we brushed the sand sediments over the buried remains, to our surprise we discovered well-preserved bones," Sarno says. "The skeleton was preserved as if these giant animals had been resting there quietly for millions of years. It seems that they were buried in a sudden flood of an ancient river." About a year ago Serano led another expedition that excavated near the Morocco-Algiers border. The uncovered skull, which is more than one and a half meters long, is larger than the skull of Tyrannosaurus Rex, which lived 70-65 million years ago in North America, and is considered the largest predator among the giant lizards that ruled the Earth in the Jurassic and Cretaceous eras. Sarno named the skull Carcharodontosaurus saharicus, which means "the shark-toothed reptile of the Sahara". Its brain cavity is well preserved and reaches half the brain size of Tyrannosaurus rex (15th the size of a human brain). It probably fed on small plant-eating dinosaurs. Sarno estimates its length at about 14 meters.
The fossils that were uncovered solved a mystery of fossilized bones and teeth that were discovered in Egypt at the beginning of the century and were destroyed in World War II. No one knew who they belonged to, but the teeth in the giant skull found in Morocco matched the description of the teeth found in Egypt, and they apparently belonged to the same type of dinosaur discovered by Sarno.
When the dinosaurs appeared about 230 million years ago during the Triassic period, all the continents were connected together in a supercontinent known as Pangea. Free-roaming dinosaurs were similar everywhere on the continent.
80 million years later, towards the end of the Jurassic period, the Pangea continent broke into two subcontinents: a northern continent - Eurasia, and a southern continent - Gondwana, with the ancient Tethys Ocean between them. During the next geological period - the Cretaceous - 146 to 65 million years ago, the continents moved away from each other and eventually reached their current location.
At the time when the dinosaur that was discovered in Africa appeared, about 90 million years ago, the world appeared as a patchwork of isolated continents, each with its own dinosaur forms, which developed separately after being separated from each other. Like all forms of life, the different species of dinosaurs also evolved and changed over the years according to the conditions of the place where they lived. This is how human-sized carnivorous dinosaurs evolved in Mongolia, rhinoceros-like vegetarian dinosaurs in North America, and more.
Until recently, no one knew what the dinosaurs looked like in Africa. For many years, scientists believed that the dinosaurs evolved from two groups: a northern group originating in Laurasia, and a southern group originating in Gondwana. The basis for this idea were finds of strange dinosaurs discovered in South America. These dinosaurs, with a pair of horns above their eyes, were unlike any of the northern dinosaurs.
Because Africa and South America were included in the continent of Gondwana, and both were isolated from northern Eurasia, scientists assumed that the dinosaurs in Africa would be different from the northern ones but similar to their South American counterparts. The remains of the dinosaur found in Africa turned the theory upside down, in that they were not similar to the South American predator but rather to the giant dinosaur that lived in North America during the early Cretaceous period.
What can explain the similarity between the early Cretaceous African dinosaurs and those from the northern continents? Sarno believes that land bridges or shallow sea areas remained between Eurasia and Gondwana after they broke off from each other. These areas allowed the migration of dinosaurs from continent to continent and this explains the similarity between certain dinosaur species in the world.
After Africa and South America separated from the northern continents, they began to separate from each other and the Atlantic Ocean stretched between them. This happened about 90 million years ago. On each of the two continents, some dinosaurs became extinct and some survived. One of the survivors was the dinosaur whose remains were found in Morocco last year. From then on, the African dinosaurs continued to develop in complete isolation - this is what Sarno believes, who wants to return to Africa in a few years and look for findings that will substantiate his hypotheses. According to Sarno, the story of the dinosaurs in Africa has only just begun.
**********
A dinosaur's nest ("Haaretz" 16/02/97)
e-mail
The inhabitants of the Indian village, who were plowing the wheat and cotton fields, thought they had come across rocks, but scientists who arrived at the scene were happy to discover that they were fossilized dinosaur eggs. In recent years, residents of the village of Pisdora - 700 km northeast of Bombay - have come across these eggs, which are about 15 cm long and 7.5 cm wide, more than once, but only recently did scientists learn about the findings.
"The villagers were not aware of the importance of the fossils," said Dr. Giani Badam, a paleontologist from the nearby Deccan College. The villagers also found fossilized bones and dung in their fields. In total, more than 300 dinosaur eggs were found around the village, in groups of four to ten eggs.
"The eggs look just like stones," said farmer Kinsa Dadamal, "and then people come in cars and take them away. The bones do look like the bones of an animal, but it must have been a very large animal."
According to Badam, the dinosaurs that laid these eggs lived 65 million years ago. The study of the remains may provide clues as to the cause of the disappearance of these giant animals. The dinosaur embryos in the eggs may have suffocated due to volcanic eruptions, but it will take about six months before the samples sent for biochemical tests will provide information about the size of the dinosaurs, their eating habits and the environment in which they lived.
From tests of stone fossils and vegetation found around the eggs, it was discovered that these dinosaurs had four legs and a long neck, avoided eating meat and fed on pine cones and ferns.
The scientists were called to the village by Vikas Amata, a doctor and environmental activist who oversees a rehabilitation project for lepers and the disabled near Pisadura.
"The whole area needs to be fenced off," he said. "Every site where dinosaur remains are found is of national importance. The area should be turned into a park like Jurassic Park." In the early nineties, tools, carvings and ornaments dating to the Stone Age were found in the villages near Pisdora.
Seashells of various sizes found at the site led the researchers to assume that this area, which is now in the heart of the land, was once part of the coastal plain, and volcanic eruptions caused its elevation.
To extract blood from a fossil ("Haaretz" 10/07/97).
New York Times
Scientists from the University of Montana say they managed to extract blood remains from the bones of a dinosaur that died about 65 million years ago. This is the first time this has been done. In this way, science is approaching - to an extent that it has never been before - the fantasy of science fiction about the re-creation of creatures that once lived, using the genetic information found in their blood cells. Unlike most fossils found so far, the dinosaur skeleton, a nearly complete Tyrannosaurus rex found in eastern Montana, was buried in conditions that prevented its bones from breaking down into minerals, thus preserving the interior of the bone in its original state.
Because of the good condition in which the bones were kept, Dr. Mary H. Schweitzer, a paleontologist at the University of Montana, to look for direct signs of life, such as cells, DNA and proteins.
The practice of extracting ancient molecules is a fascinating but extremely treacherous field, and many scientists have stumbled into it. The more sensitive the extraction technique, the greater the chance of "exiling" molecules that contaminated the source. For example, the claim by a team of researchers from Utah that they succeeded in extracting DNA from the bones of an 80-million-year-old dinosaur was later refuted by other researchers, who claimed that it was a human genetic code. Due to concerns of this type, Dr. Schweitzer and her colleagues acted cautiously and waited several years before publishing their findings. Dr. Schweitzer emphasized that she was unable to find any direct evidence of the presence of cells, but a chemical used to detect DNA was able to pick up something in the holes where the blood cells were supposed to be. According to her, she was unable to find DNA that could be clearly identified as belonging to a dinosaur. However, she and her colleagues were more successful in searching for recycled mutin - the part of hemoglobin that serves as the oxygen carrier in the blood. In the June issue of the journal Academy of Science The Proceedings of the National, they report that they were able to find evidence of the presence of hematin in six separate chemical tests. In one of the experiments, they injected crushed dinosaur bone into mice in an attempt to see if they would develop a vaccine against the blood of the dinosaur. Since they could not get a dinosaur to take his blood, the scientists chose a substitute in the form of a turkey. The choice was based on the theory that the origin of birds is from the dinosaurs and therefore the turkey is a distant relative of the Tyrannosaurus rex. The mice did react to the blood, evidence that they had developed genes for some part of the hemoglobin molecule.
According to Dr. Schweitzer, the immune system of the mice apparently reacted to a small part of the hemoglobin molecule and not to all of it. Another chemical test raised the possibility that the condensed hemotin is attached to a protein particle.
Dr. S. Blair Hedges, an evolutionary biologist at Pennsylvania State University, says that Dr. Schweitzer's paper convinced him, since he himself was able to collect "a fairly significant body of evidence supporting the possibility of the preservation of biological molecules in dinosaur bones."
Dr. Norman R. Pace, a member of the National Academy of Sciences, who recommended the publication of Dr. Schweitzer's article in the academy's journal, says that in his opinion "she did a very careful job, the best that can be done given the current technology." The importance of Schweitzer's work lies, apparently, in the message it conveys to other fossil researchers, according to which it makes sense to look for biological molecules in fossils, although this should be done with caution. Dr. Schweitzer believes that the fact that the dinosaur bones almost did not undergo a mineralization process is out of the ordinary, but not unique, and it is possible to find molecular evidence preserved in other fossils as well.
The importance of extracting DNA from fossils is that it may help reconstruct evolutionary development. Proteins, for example, may provide immunological information that can clarify the relationships between already extinct species.
